[browser] samplepoint instrumentation into Mono profiler

src/mono/browser/runtime/cwraps.ts

@@ -63,7 +63,6 @@ const fn_signatures: SigLine[] = [
  [() => !runtimeHelpers.emscriptenBuildOptions.enableAotProfiler, "mono_wasm_profiler_init_aot", "void", ["string"]],
  [() => !runtimeHelpers.emscriptenBuildOptions.enableBrowserProfiler, "mono_wasm_profiler_init_browser", "void", ["string"]],
  [() => !runtimeHelpers.emscriptenBuildOptions.enableLogProfiler, "mono_wasm_profiler_init_log", "void", ["string"]],
- [true, "mono_wasm_profiler_init_browser", "void", ["number"]],
  [false, "mono_wasm_exec_regression", "number", ["number", "string"]],
  [false, "mono_wasm_invoke_jsexport", "void", ["number", "number"]],
  [true, "mono_wasm_write_managed_pointer_unsafe", "void", ["number", "number"]],
@@ -73,6 +72,7 @@ const fn_signatures: SigLine[] = [
  [true, "mono_wasm_f64_to_i52", "number", ["number", "number"]],
  [true, "mono_wasm_f64_to_u52", "number", ["number", "number"]],
  [true, "mono_wasm_method_get_name", "number", ["number"]],
+ [true, "mono_wasm_method_get_name_ex", "number", ["number"]],
  [true, "mono_wasm_method_get_full_name", "number", ["number"]],
  [true, "mono_wasm_gc_lock", "void", []],
  [true, "mono_wasm_gc_unlock", "void", []],
@@ -131,6 +131,9 @@ const fn_signatures: SigLine[] = [
  [true, "mono_jiterp_end_catch", "void", []],
  [true, "mono_interp_pgo_load_table", "number", ["number", "number"]],
  [true, "mono_interp_pgo_save_table", "number", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_enter", "void", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_samplepoint", "void", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_leave", "void", ["number", "number"]],
 
  ...threading_cwraps,
 ];
@@ -193,6 +196,7 @@ export interface t_Cwraps {
  mono_wasm_f64_to_i52(destination: VoidPtr, value: number): I52Error;
  mono_wasm_f64_to_u52(destination: VoidPtr, value: number): I52Error;
  mono_wasm_method_get_name(method: MonoMethod): CharPtr;
+ mono_wasm_method_get_name_ex(method: MonoMethod): CharPtr;
  mono_wasm_method_get_full_name(method: MonoMethod): CharPtr;
  mono_wasm_gc_lock(): void;
  mono_wasm_gc_unlock(): void;

src/mono/browser/runtime/driver.c

@@ -534,6 +534,22 @@ EMSCRIPTEN_KEEPALIVE const char * mono_wasm_method_get_name (MonoMethod *method)
 	return res;
 }
 
+EMSCRIPTEN_KEEPALIVE const char * mono_wasm_method_get_name_ex (MonoMethod *method) {
+	const char *res;
+	MONO_ENTER_GC_UNSAFE;
+	res = mono_method_get_name (method);
+	// starts with .ctor or .cctor
+	if (mono_method_get_flags (method, NULL) & 0x0800 /* METHOD_ATTRIBUTE_SPECIAL_NAME */ && strlen (res) < 7) {
+ char *res_ex = (char *) malloc (128);
+ snprintf (res_ex, 128,"%s.%s", mono_class_get_name (mono_method_get_class (method)), res);
+ res = res_ex;
+	} else {
+ res = strdup (res);
+	}
+	MONO_EXIT_GC_UNSAFE;
+	return res;
+}
+
 EMSCRIPTEN_KEEPALIVE float mono_wasm_get_f32_unaligned (const float *src) {
 	return *src;
 }

src/mono/browser/runtime/es6/dotnet.es6.lib.js

@@ -90,6 +90,7 @@ function injectDependencies() {
  `enablePerfTracing: ${FEATURE_PERFTRACING ? "true" : "false"}, ` +
  `enableAotProfiler: ${ENABLE_AOT_PROFILER ? "true" : "false"}, ` +
  `enableBrowserProfiler: ${ENABLE_BROWSER_PROFILER ? "true" : "false"}, ` +
+ `enablePerfTracing: ${ENABLE_BROWSER_PROFILER ? "true" : "false"}, ` +
  `enableLogProfiler: ${ENABLE_LOG_PROFILER ? "true" : "false"}, ` +
  `runAOTCompilation: ${RUN_AOT_COMPILATION ? "true" : "false"}, ` +
  `wasmEnableThreads: ${USE_PTHREADS ? "true" : "false"}, ` +

src/mono/browser/runtime/exports-binding.ts

@@ -6,14 +6,14 @@ import WasmEnableThreads from "consts:wasmEnableThreads";
 import { mono_wasm_debugger_log, mono_wasm_add_dbg_command_received, mono_wasm_set_entrypoint_breakpoint, mono_wasm_fire_debugger_agent_message_with_data, mono_wasm_fire_debugger_agent_message_with_data_to_pause } from "./debug";
 import { mono_wasm_release_cs_owned_object } from "./gc-handles";
 import { mono_wasm_bind_js_import_ST, mono_wasm_invoke_js_function, mono_wasm_invoke_jsimport_MT, mono_wasm_invoke_jsimport_ST } from "./invoke-js";
-import { mono_interp_tier_prepare_jiterpreter, mono_jiterp_free_method_data_js } from "./jiterpreter";
+import { mono_interp_tier_prepare_jiterpreter, mono_wasm_free_method_data } from "./jiterpreter";
 import { mono_interp_jit_wasm_entry_trampoline, mono_interp_record_interp_entry } from "./jiterpreter-interp-entry";
 import { mono_interp_jit_wasm_jit_call_trampoline, mono_interp_invoke_wasm_jit_call_trampoline, mono_interp_flush_jitcall_queue } from "./jiterpreter-jit-call";
 import { mono_wasm_resolve_or_reject_promise } from "./marshal-to-js";
 import { mono_wasm_schedule_timer, schedule_background_exec } from "./scheduling";
 import { mono_wasm_asm_loaded } from "./startup";
 import { mono_log_warn, mono_wasm_console_clear, mono_wasm_trace_logger } from "./logging";
-import { mono_wasm_profiler_leave, mono_wasm_profiler_enter, ds_rt_websocket_close, ds_rt_websocket_create, ds_rt_websocket_poll, ds_rt_websocket_recv, ds_rt_websocket_send } from "./profiler";
+import { mono_wasm_profiler_record, mono_wasm_profiler_now, ds_rt_websocket_close, ds_rt_websocket_create, ds_rt_websocket_poll, ds_rt_websocket_recv, ds_rt_websocket_send } from "./profiler";
 import { mono_wasm_browser_entropy } from "./crypto";
 import { mono_wasm_cancel_promise } from "./cancelable-promise";
 
@@ -68,10 +68,10 @@ export const mono_wasm_imports = [
  mono_interp_jit_wasm_jit_call_trampoline,
  mono_interp_invoke_wasm_jit_call_trampoline,
  mono_interp_flush_jitcall_queue,
-mono_jiterp_free_method_data_js,
+mono_wasm_free_method_data,
 
-mono_wasm_profiler_enter,
-mono_wasm_profiler_leave,
+mono_wasm_profiler_now,
+mono_wasm_profiler_record,
 
  // driver.c
  mono_wasm_trace_logger,

src/mono/browser/runtime/jiterpreter-support.ts

@@ -1600,6 +1600,27 @@ export const _now = (globalThis.performance && globalThis.performance.now)
 
 let scratchBuffer: NativePointer = <any>0;
 
+export function append_profiler_event (builder: WasmBuilder, ip: MintOpcodePtr, opcode: MintOpcode) {
+ let event_name:string;
+ switch (opcode) {
+ case MintOpcode.MINT_PROF_ENTER:
+ event_name = "prof_enter";
+ break;
+ case MintOpcode.MINT_PROF_SAMPLEPOINT:
+ event_name = "prof_samplepoint";
+ break;
+ case MintOpcode.MINT_PROF_EXIT:
+ case MintOpcode.MINT_PROF_EXIT_VOID:
+ event_name = "prof_leave";
+ break;
+ default:
+ throw new Error(`Unimplemented profiler event ${opcode}`);
+ }
+ builder.local("frame");
+ builder.i32_const(ip);
+ builder.callImport(event_name);
+}
+
 export function append_safepoint (builder: WasmBuilder, ip: MintOpcodePtr) {
  // safepoints are never triggered in a single-threaded build
  if (!WasmEnableThreads)

src/mono/browser/runtime/jiterpreter-trace-generator.ts

@@ -28,6 +28,7 @@ import {
  try_append_memmove_fast, getOpcodeTableValue,
  getMemberOffset, isZeroPageReserved, CfgBranchType,
  append_safepoint, modifyCounter, simdFallbackCounters,
+ append_profiler_event,
 } from "./jiterpreter-support";
 import {
  sizeOfDataItem, sizeOfV128, sizeOfStackval,
@@ -1415,9 +1416,15 @@ export function generateWasmBody (
  }
 
  case MintOpcode.MINT_RETHROW:
+ ip = abort;
+ break;
+
+ // call C
+ case MintOpcode.MINT_PROF_ENTER:
+ case MintOpcode.MINT_PROF_SAMPLEPOINT:
  case MintOpcode.MINT_PROF_EXIT:
  case MintOpcode.MINT_PROF_EXIT_VOID:
-ip = abort;
+append_profiler_event(builder, ip, opcode);
  break;
 
  // Generating code for these is kind of complex due to the intersection of JS and int64,

src/mono/browser/runtime/jiterpreter.ts

@@ -26,6 +26,7 @@ import { mono_jiterp_free_method_data_interp_entry } from "./jiterpreter-interp-
 import { mono_jiterp_free_method_data_jit_call } from "./jiterpreter-jit-call";
 import { mono_log_error, mono_log_info, mono_log_warn } from "./logging";
 import { utf8ToString } from "./strings";
+import { mono_wasm_profiler_free_method } from "./profiler";
 
 // Controls miscellaneous diagnostic output.
 export const trace = 0;
@@ -298,6 +299,12 @@ function getTraceImports () {
  if (nullCheckValidation)
  traceImports.push(importDef("notnull", assert_not_null));
 
+ if (runtimeHelpers.emscriptenBuildOptions.enablePerfTracing) {
+ traceImports.push(importDef("prof_enter", getRawCwrap("mono_jiterp_prof_enter")));
+ traceImports.push(importDef("prof_samplepoint", getRawCwrap("mono_jiterp_prof_samplepoint")));
+ traceImports.push(importDef("prof_leave", getRawCwrap("mono_jiterp_prof_leave")));
+ }
+
  const pushMathOps = (list: string[], type: string) => {
  for (let i = 0; i < list.length; i++) {
  const mop = list[i];
@@ -579,6 +586,30 @@ function initialize_builder (builder: WasmBuilder) {
  },
  WasmValtype.void, true
  );
+ builder.defineType(
+ "prof_enter",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
+ builder.defineType(
+ "prof_samplepoint",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
+ builder.defineType(
+ "prof_leave",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
  builder.defineType(
  "hashcode",
  {
@@ -1050,9 +1081,13 @@ export function mono_interp_tier_prepare_jiterpreter (
 
 // NOTE: This will potentially be called once for every trace entry point
 // in a given method, not just once per method
-export function mono_jiterp_free_method_data_js (
+export function mono_wasm_free_method_data (
  method: MonoMethod, imethod: number, traceIndex: number
 ) {
+ if (runtimeHelpers.emscriptenBuildOptions.enablePerfTracing) {
+ mono_wasm_profiler_free_method(method);
+ }
+
  // TODO: Uninstall the trace function pointer from the function pointer table,
  // so that the compiled trace module can be freed by the browser eventually
  // Release the trace info object, if present

src/mono/browser/runtime/profiler.ts

@@ -7,6 +7,7 @@ import { ENVIRONMENT_IS_WEB, mono_assert, runtimeHelpers } from "./globals";
 import { MonoMethod, AOTProfilerOptions, BrowserProfilerOptions, LogProfilerOptions } from "./types/internal";
 import { profiler_c_functions as cwraps } from "./cwraps";
 import { utf8ToString } from "./strings";
+import { free } from "./memory";
 
 // Initialize the AOT profiler with OPTIONS.
 // Requires the AOT profiler to be linked into the app.
@@ -32,7 +33,13 @@ export function mono_wasm_init_browser_profiler (options: BrowserProfilerOptions
  mono_assert(runtimeHelpers.emscriptenBuildOptions.enableBrowserProfiler, "Browser profiler is not enabled, please use <WasmProfilers>browser;</WasmProfilers> in your project file.");
  if (options == null)
  options = {};
- const arg = "browser:";
+ let arg = "browser:";
+ if (typeof options.callSpec === "string") {
+ arg += `callspec=${options.callSpec},`;
+ }
+ if (typeof options.sampleIntervalMs === "number") {
+ arg += `interval=${options.sampleIntervalMs},`;
+ }
  cwraps.mono_wasm_profiler_init_browser(arg);
 }
 
@@ -76,6 +83,7 @@ export function startMeasure (): TimeStamp {
 
 export function endMeasure (start: TimeStamp, block: string, id?: string) {
  if (runtimeHelpers.enablePerfMeasure && start) {
+ // API is slightly different between web and Nodejs
  const options = ENVIRONMENT_IS_WEB
  ? { start: start as any }
  : { startTime: start as any };
@@ -84,28 +92,27 @@ export function endMeasure (start: TimeStamp, block: string, id?: string) {
  }
 }
 
-const stackFrames: number[] = [];
-export function mono_wasm_profiler_enter (): void {
- if (runtimeHelpers.enablePerfMeasure) {
- stackFrames.push(globalThis.performance.now());
- }
+export function mono_wasm_profiler_now (): number {
+ return globalThis.performance.now();
+}
+
+export function mono_wasm_profiler_free_method (method: MonoMethod): void {
+ methodNames.delete(method as any);
 }
 
 const methodNames: Map<number, string> = new Map();
-export function mono_wasm_profiler_leave (method: MonoMethod): void {
- if (runtimeHelpers.enablePerfMeasure) {
- const start = stackFrames.pop();
- const options = ENVIRONMENT_IS_WEB
- ? { start: start }
- : { startTime: start };
- let methodName = methodNames.get(method as any);
- if (!methodName) {
- const chars = cwraps.mono_wasm_method_get_name(method);
- methodName = utf8ToString(chars);
- methodNames.set(method as any, methodName);
- }
- globalThis.performance.measure(methodName, options);
+export function mono_wasm_profiler_record (method: MonoMethod, start: number): void {
+ const options = ENVIRONMENT_IS_WEB
+ ? { start: start }
+ : { startTime: start };
+ let methodName = methodNames.get(method as any);
+ if (!methodName) {
+ const chars = cwraps.mono_wasm_method_get_name_ex(method);
+ methodName = utf8ToString(chars);
+ methodNames.set(method as any, methodName);
+ free(chars as any);
  }
+ globalThis.performance.measure(methodName, options);
 }
 
 /* eslint-disable @typescript-eslint/no-unused-vars */

src/mono/browser/runtime/types/internal.ts

@@ -259,6 +259,12 @@ export type AOTProfilerOptions = {
 }
 
 export type BrowserProfilerOptions = {
+ sampleIntervalMs?: number, // default: 1000
+ /**
+ * See callspec in https://github.com/dotnet/runtime/blob/main/docs/design/mono/diagnostics-tracing.md#trace-monovm-profiler-events-during-startup
+ * When used together with Mono AOT, the callspec needs to match one in <WasmProfilers>browser:callspec=N:Sample;</WasmProfilers> in your project file.
+ */
+ callSpec?: string,
 }
 
 export type LogProfilerOptions = {

src/mono/mono/metadata/jit-icall-reg.h

@@ -250,6 +250,7 @@ MONO_JIT_ICALL (mono_ppc_throw_exception)	\
 MONO_JIT_ICALL (mono_profiler_raise_exception_clause) \
 MONO_JIT_ICALL (mono_profiler_raise_gc_allocation) \
 MONO_JIT_ICALL (mono_profiler_raise_method_enter) \
+MONO_JIT_ICALL (mono_profiler_raise_method_samplepoint) \
 MONO_JIT_ICALL (mono_profiler_raise_method_leave) \
 MONO_JIT_ICALL (mono_profiler_raise_method_tail_call) \
 MONO_JIT_ICALL (mono_resolve_generic_virtual_call) \
@@ -298,6 +299,7 @@ MONO_JIT_ICALL (mono_throw_platform_not_supported) \
 MONO_JIT_ICALL (mono_throw_invalid_program) \
 MONO_JIT_ICALL (mono_throw_type_load) \
 MONO_JIT_ICALL (mono_trace_enter_method) \
+MONO_JIT_ICALL (mono_trace_samplepoint_method) \
 MONO_JIT_ICALL (mono_trace_leave_method) \
 MONO_JIT_ICALL (mono_trace_tail_method) \
 MONO_JIT_ICALL (mono_upgrade_remote_class_wrapper) \

src/mono/browser/runtime/cwraps.ts

@@ -63,7 +63,6 @@ const fn_signatures: SigLine[] = [
  [() => !runtimeHelpers.emscriptenBuildOptions.enableAotProfiler, "mono_wasm_profiler_init_aot", "void", ["string"]],
  [() => !runtimeHelpers.emscriptenBuildOptions.enableBrowserProfiler, "mono_wasm_profiler_init_browser", "void", ["string"]],
  [() => !runtimeHelpers.emscriptenBuildOptions.enableLogProfiler, "mono_wasm_profiler_init_log", "void", ["string"]],
- [true, "mono_wasm_profiler_init_browser", "void", ["number"]],
  [false, "mono_wasm_exec_regression", "number", ["number", "string"]],
  [false, "mono_wasm_invoke_jsexport", "void", ["number", "number"]],
  [true, "mono_wasm_write_managed_pointer_unsafe", "void", ["number", "number"]],
@@ -73,6 +72,7 @@ const fn_signatures: SigLine[] = [
  [true, "mono_wasm_f64_to_i52", "number", ["number", "number"]],
  [true, "mono_wasm_f64_to_u52", "number", ["number", "number"]],
  [true, "mono_wasm_method_get_name", "number", ["number"]],
+ [true, "mono_wasm_method_get_name_ex", "number", ["number"]],
  [true, "mono_wasm_method_get_full_name", "number", ["number"]],
  [true, "mono_wasm_gc_lock", "void", []],
  [true, "mono_wasm_gc_unlock", "void", []],
@@ -131,6 +131,9 @@ const fn_signatures: SigLine[] = [
  [true, "mono_jiterp_end_catch", "void", []],
  [true, "mono_interp_pgo_load_table", "number", ["number", "number"]],
  [true, "mono_interp_pgo_save_table", "number", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_enter", "void", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_samplepoint", "void", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_leave", "void", ["number", "number"]],
 
  ...threading_cwraps,
 ];
@@ -193,6 +196,7 @@ export interface t_Cwraps {
  mono_wasm_f64_to_i52(destination: VoidPtr, value: number): I52Error;
  mono_wasm_f64_to_u52(destination: VoidPtr, value: number): I52Error;
  mono_wasm_method_get_name(method: MonoMethod): CharPtr;
+ mono_wasm_method_get_name_ex(method: MonoMethod): CharPtr;
  mono_wasm_method_get_full_name(method: MonoMethod): CharPtr;
  mono_wasm_gc_lock(): void;
  mono_wasm_gc_unlock(): void;

src/mono/browser/runtime/driver.c

@@ -534,6 +534,22 @@ EMSCRIPTEN_KEEPALIVE const char * mono_wasm_method_get_name (MonoMethod *method)
 	return res;
 }
 
+EMSCRIPTEN_KEEPALIVE const char * mono_wasm_method_get_name_ex (MonoMethod *method) {
+	const char *res;
+	MONO_ENTER_GC_UNSAFE;
+	res = mono_method_get_name (method);
+	// starts with .ctor or .cctor
+	if (mono_method_get_flags (method, NULL) & 0x0800 /* METHOD_ATTRIBUTE_SPECIAL_NAME */ && strlen (res) < 7) {
+ char *res_ex = (char *) malloc (128);
+ snprintf (res_ex, 128,"%s.%s", mono_class_get_name (mono_method_get_class (method)), res);
+ res = res_ex;
+	} else {
+ res = strdup (res);
+	}
+	MONO_EXIT_GC_UNSAFE;
+	return res;
+}
+
 EMSCRIPTEN_KEEPALIVE float mono_wasm_get_f32_unaligned (const float *src) {
 	return *src;
 }

src/mono/browser/runtime/es6/dotnet.es6.lib.js

@@ -90,6 +90,7 @@ function injectDependencies() {
  `enablePerfTracing: ${FEATURE_PERFTRACING ? "true" : "false"}, ` +
  `enableAotProfiler: ${ENABLE_AOT_PROFILER ? "true" : "false"}, ` +
  `enableBrowserProfiler: ${ENABLE_BROWSER_PROFILER ? "true" : "false"}, ` +
+ `enablePerfTracing: ${ENABLE_BROWSER_PROFILER ? "true" : "false"}, ` +
  `enableLogProfiler: ${ENABLE_LOG_PROFILER ? "true" : "false"}, ` +
  `runAOTCompilation: ${RUN_AOT_COMPILATION ? "true" : "false"}, ` +
  `wasmEnableThreads: ${USE_PTHREADS ? "true" : "false"}, ` +

src/mono/browser/runtime/exports-binding.ts

@@ -6,14 +6,14 @@ import WasmEnableThreads from "consts:wasmEnableThreads";
 import { mono_wasm_debugger_log, mono_wasm_add_dbg_command_received, mono_wasm_set_entrypoint_breakpoint, mono_wasm_fire_debugger_agent_message_with_data, mono_wasm_fire_debugger_agent_message_with_data_to_pause } from "./debug";
 import { mono_wasm_release_cs_owned_object } from "./gc-handles";
 import { mono_wasm_bind_js_import_ST, mono_wasm_invoke_js_function, mono_wasm_invoke_jsimport_MT, mono_wasm_invoke_jsimport_ST } from "./invoke-js";
-import { mono_interp_tier_prepare_jiterpreter, mono_jiterp_free_method_data_js } from "./jiterpreter";
+import { mono_interp_tier_prepare_jiterpreter, mono_wasm_free_method_data } from "./jiterpreter";
 import { mono_interp_jit_wasm_entry_trampoline, mono_interp_record_interp_entry } from "./jiterpreter-interp-entry";
 import { mono_interp_jit_wasm_jit_call_trampoline, mono_interp_invoke_wasm_jit_call_trampoline, mono_interp_flush_jitcall_queue } from "./jiterpreter-jit-call";
 import { mono_wasm_resolve_or_reject_promise } from "./marshal-to-js";
 import { mono_wasm_schedule_timer, schedule_background_exec } from "./scheduling";
 import { mono_wasm_asm_loaded } from "./startup";
 import { mono_log_warn, mono_wasm_console_clear, mono_wasm_trace_logger } from "./logging";
-import { mono_wasm_profiler_leave, mono_wasm_profiler_enter, ds_rt_websocket_close, ds_rt_websocket_create, ds_rt_websocket_poll, ds_rt_websocket_recv, ds_rt_websocket_send } from "./profiler";
+import { mono_wasm_profiler_record, mono_wasm_profiler_now, ds_rt_websocket_close, ds_rt_websocket_create, ds_rt_websocket_poll, ds_rt_websocket_recv, ds_rt_websocket_send } from "./profiler";
 import { mono_wasm_browser_entropy } from "./crypto";
 import { mono_wasm_cancel_promise } from "./cancelable-promise";
 
@@ -68,10 +68,10 @@ export const mono_wasm_imports = [
  mono_interp_jit_wasm_jit_call_trampoline,
  mono_interp_invoke_wasm_jit_call_trampoline,
  mono_interp_flush_jitcall_queue,
-mono_jiterp_free_method_data_js,
+mono_wasm_free_method_data,
 
-mono_wasm_profiler_enter,
-mono_wasm_profiler_leave,
+mono_wasm_profiler_now,
+mono_wasm_profiler_record,
 
  // driver.c
  mono_wasm_trace_logger,

src/mono/browser/runtime/jiterpreter-support.ts

@@ -1600,6 +1600,27 @@ export const _now = (globalThis.performance && globalThis.performance.now)
 
 let scratchBuffer: NativePointer = <any>0;
 
+export function append_profiler_event (builder: WasmBuilder, ip: MintOpcodePtr, opcode: MintOpcode) {
+ let event_name:string;
+ switch (opcode) {
+ case MintOpcode.MINT_PROF_ENTER:
+ event_name = "prof_enter";
+ break;
+ case MintOpcode.MINT_PROF_SAMPLEPOINT:
+ event_name = "prof_samplepoint";
+ break;
+ case MintOpcode.MINT_PROF_EXIT:
+ case MintOpcode.MINT_PROF_EXIT_VOID:
+ event_name = "prof_leave";
+ break;
+ default:
+ throw new Error(`Unimplemented profiler event ${opcode}`);
+ }
+ builder.local("frame");
+ builder.i32_const(ip);
+ builder.callImport(event_name);
+}
+
 export function append_safepoint (builder: WasmBuilder, ip: MintOpcodePtr) {
  // safepoints are never triggered in a single-threaded build
  if (!WasmEnableThreads)

src/mono/browser/runtime/jiterpreter-trace-generator.ts

@@ -28,6 +28,7 @@ import {
  try_append_memmove_fast, getOpcodeTableValue,
  getMemberOffset, isZeroPageReserved, CfgBranchType,
  append_safepoint, modifyCounter, simdFallbackCounters,
+ append_profiler_event,
 } from "./jiterpreter-support";
 import {
  sizeOfDataItem, sizeOfV128, sizeOfStackval,
@@ -1415,9 +1416,15 @@ export function generateWasmBody (
  }
 
  case MintOpcode.MINT_RETHROW:
+ ip = abort;
+ break;
+
+ // call C
+ case MintOpcode.MINT_PROF_ENTER:
+ case MintOpcode.MINT_PROF_SAMPLEPOINT:
  case MintOpcode.MINT_PROF_EXIT:
  case MintOpcode.MINT_PROF_EXIT_VOID:
-ip = abort;
+append_profiler_event(builder, ip, opcode);
  break;
 
  // Generating code for these is kind of complex due to the intersection of JS and int64,

src/mono/browser/runtime/jiterpreter.ts

@@ -26,6 +26,7 @@ import { mono_jiterp_free_method_data_interp_entry } from "./jiterpreter-interp-
 import { mono_jiterp_free_method_data_jit_call } from "./jiterpreter-jit-call";
 import { mono_log_error, mono_log_info, mono_log_warn } from "./logging";
 import { utf8ToString } from "./strings";
+import { mono_wasm_profiler_free_method } from "./profiler";
 
 // Controls miscellaneous diagnostic output.
 export const trace = 0;
@@ -298,6 +299,12 @@ function getTraceImports () {
  if (nullCheckValidation)
  traceImports.push(importDef("notnull", assert_not_null));
 
+ if (runtimeHelpers.emscriptenBuildOptions.enablePerfTracing) {
+ traceImports.push(importDef("prof_enter", getRawCwrap("mono_jiterp_prof_enter")));
+ traceImports.push(importDef("prof_samplepoint", getRawCwrap("mono_jiterp_prof_samplepoint")));
+ traceImports.push(importDef("prof_leave", getRawCwrap("mono_jiterp_prof_leave")));
+ }
+
  const pushMathOps = (list: string[], type: string) => {
  for (let i = 0; i < list.length; i++) {
  const mop = list[i];
@@ -579,6 +586,30 @@ function initialize_builder (builder: WasmBuilder) {
  },
  WasmValtype.void, true
  );
+ builder.defineType(
+ "prof_enter",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
+ builder.defineType(
+ "prof_samplepoint",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
+ builder.defineType(
+ "prof_leave",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
  builder.defineType(
  "hashcode",
  {
@@ -1050,9 +1081,13 @@ export function mono_interp_tier_prepare_jiterpreter (
 
 // NOTE: This will potentially be called once for every trace entry point
 // in a given method, not just once per method
-export function mono_jiterp_free_method_data_js (
+export function mono_wasm_free_method_data (
  method: MonoMethod, imethod: number, traceIndex: number
 ) {
+ if (runtimeHelpers.emscriptenBuildOptions.enablePerfTracing) {
+ mono_wasm_profiler_free_method(method);
+ }
+
  // TODO: Uninstall the trace function pointer from the function pointer table,
  // so that the compiled trace module can be freed by the browser eventually
  // Release the trace info object, if present

src/mono/browser/runtime/profiler.ts

@@ -7,6 +7,7 @@ import { ENVIRONMENT_IS_WEB, mono_assert, runtimeHelpers } from "./globals";
 import { MonoMethod, AOTProfilerOptions, BrowserProfilerOptions, LogProfilerOptions } from "./types/internal";
 import { profiler_c_functions as cwraps } from "./cwraps";
 import { utf8ToString } from "./strings";
+import { free } from "./memory";
 
 // Initialize the AOT profiler with OPTIONS.
 // Requires the AOT profiler to be linked into the app.
@@ -32,7 +33,13 @@ export function mono_wasm_init_browser_profiler (options: BrowserProfilerOptions
  mono_assert(runtimeHelpers.emscriptenBuildOptions.enableBrowserProfiler, "Browser profiler is not enabled, please use <WasmProfilers>browser;</WasmProfilers> in your project file.");
  if (options == null)
  options = {};
- const arg = "browser:";
+ let arg = "browser:";
+ if (typeof options.callSpec === "string") {
+ arg += `callspec=${options.callSpec},`;
+ }
+ if (typeof options.sampleIntervalMs === "number") {
+ arg += `interval=${options.sampleIntervalMs},`;
+ }
  cwraps.mono_wasm_profiler_init_browser(arg);
 }
 
@@ -76,6 +83,7 @@ export function startMeasure (): TimeStamp {
 
 export function endMeasure (start: TimeStamp, block: string, id?: string) {
  if (runtimeHelpers.enablePerfMeasure && start) {
+ // API is slightly different between web and Nodejs
  const options = ENVIRONMENT_IS_WEB
  ? { start: start as any }
  : { startTime: start as any };
@@ -84,28 +92,27 @@ export function endMeasure (start: TimeStamp, block: string, id?: string) {
  }
 }
 
-const stackFrames: number[] = [];
-export function mono_wasm_profiler_enter (): void {
- if (runtimeHelpers.enablePerfMeasure) {
- stackFrames.push(globalThis.performance.now());
- }
+export function mono_wasm_profiler_now (): number {
+ return globalThis.performance.now();
+}
+
+export function mono_wasm_profiler_free_method (method: MonoMethod): void {
+ methodNames.delete(method as any);
 }
 
 const methodNames: Map<number, string> = new Map();
-export function mono_wasm_profiler_leave (method: MonoMethod): void {
- if (runtimeHelpers.enablePerfMeasure) {
- const start = stackFrames.pop();
- const options = ENVIRONMENT_IS_WEB
- ? { start: start }
- : { startTime: start };
- let methodName = methodNames.get(method as any);
- if (!methodName) {
- const chars = cwraps.mono_wasm_method_get_name(method);
- methodName = utf8ToString(chars);
- methodNames.set(method as any, methodName);
- }
- globalThis.performance.measure(methodName, options);
+export function mono_wasm_profiler_record (method: MonoMethod, start: number): void {
+ const options = ENVIRONMENT_IS_WEB
+ ? { start: start }
+ : { startTime: start };
+ let methodName = methodNames.get(method as any);
+ if (!methodName) {
+ const chars = cwraps.mono_wasm_method_get_name_ex(method);
+ methodName = utf8ToString(chars);
+ methodNames.set(method as any, methodName);
+ free(chars as any);
  }
+ globalThis.performance.measure(methodName, options);
 }
 
 /* eslint-disable @typescript-eslint/no-unused-vars */

src/mono/browser/runtime/types/internal.ts

@@ -259,6 +259,12 @@ export type AOTProfilerOptions = {
 }
 
 export type BrowserProfilerOptions = {
+ sampleIntervalMs?: number, // default: 1000
+ /**
+ * See callspec in https://github.com/dotnet/runtime/blob/main/docs/design/mono/diagnostics-tracing.md#trace-monovm-profiler-events-during-startup
+ * When used together with Mono AOT, the callspec needs to match one in <WasmProfilers>browser:callspec=N:Sample;</WasmProfilers> in your project file.
+ */
+ callSpec?: string,
 }
 
 export type LogProfilerOptions = {

src/mono/mono/metadata/jit-icall-reg.h

@@ -250,6 +250,7 @@ MONO_JIT_ICALL (mono_ppc_throw_exception)	\
 MONO_JIT_ICALL (mono_profiler_raise_exception_clause) \
 MONO_JIT_ICALL (mono_profiler_raise_gc_allocation) \
 MONO_JIT_ICALL (mono_profiler_raise_method_enter) \
+MONO_JIT_ICALL (mono_profiler_raise_method_samplepoint) \
 MONO_JIT_ICALL (mono_profiler_raise_method_leave) \
 MONO_JIT_ICALL (mono_profiler_raise_method_tail_call) \
 MONO_JIT_ICALL (mono_resolve_generic_virtual_call) \
@@ -298,6 +299,7 @@ MONO_JIT_ICALL (mono_throw_platform_not_supported) \
 MONO_JIT_ICALL (mono_throw_invalid_program) \
 MONO_JIT_ICALL (mono_throw_type_load) \
 MONO_JIT_ICALL (mono_trace_enter_method) \
+MONO_JIT_ICALL (mono_trace_samplepoint_method) \
 MONO_JIT_ICALL (mono_trace_leave_method) \
 MONO_JIT_ICALL (mono_trace_tail_method) \
 MONO_JIT_ICALL (mono_upgrade_remote_class_wrapper) \

src/mono/browser/runtime/cwraps.ts

@@ -63,7 +63,6 @@ const fn_signatures: SigLine[] = [
  [() => !runtimeHelpers.emscriptenBuildOptions.enableAotProfiler, "mono_wasm_profiler_init_aot", "void", ["string"]],
  [() => !runtimeHelpers.emscriptenBuildOptions.enableBrowserProfiler, "mono_wasm_profiler_init_browser", "void", ["string"]],
  [() => !runtimeHelpers.emscriptenBuildOptions.enableLogProfiler, "mono_wasm_profiler_init_log", "void", ["string"]],
- [true, "mono_wasm_profiler_init_browser", "void", ["number"]],
  [false, "mono_wasm_exec_regression", "number", ["number", "string"]],
  [false, "mono_wasm_invoke_jsexport", "void", ["number", "number"]],
  [true, "mono_wasm_write_managed_pointer_unsafe", "void", ["number", "number"]],
@@ -73,6 +72,7 @@ const fn_signatures: SigLine[] = [
  [true, "mono_wasm_f64_to_i52", "number", ["number", "number"]],
  [true, "mono_wasm_f64_to_u52", "number", ["number", "number"]],
  [true, "mono_wasm_method_get_name", "number", ["number"]],
+ [true, "mono_wasm_method_get_name_ex", "number", ["number"]],
  [true, "mono_wasm_method_get_full_name", "number", ["number"]],
  [true, "mono_wasm_gc_lock", "void", []],
  [true, "mono_wasm_gc_unlock", "void", []],
@@ -131,6 +131,9 @@ const fn_signatures: SigLine[] = [
  [true, "mono_jiterp_end_catch", "void", []],
  [true, "mono_interp_pgo_load_table", "number", ["number", "number"]],
  [true, "mono_interp_pgo_save_table", "number", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_enter", "void", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_samplepoint", "void", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_leave", "void", ["number", "number"]],
 
  ...threading_cwraps,
 ];
@@ -193,6 +196,7 @@ export interface t_Cwraps {
  mono_wasm_f64_to_i52(destination: VoidPtr, value: number): I52Error;
  mono_wasm_f64_to_u52(destination: VoidPtr, value: number): I52Error;
  mono_wasm_method_get_name(method: MonoMethod): CharPtr;
+ mono_wasm_method_get_name_ex(method: MonoMethod): CharPtr;
  mono_wasm_method_get_full_name(method: MonoMethod): CharPtr;
  mono_wasm_gc_lock(): void;
  mono_wasm_gc_unlock(): void;

src/mono/browser/runtime/driver.c

@@ -534,6 +534,22 @@ EMSCRIPTEN_KEEPALIVE const char * mono_wasm_method_get_name (MonoMethod *method)
 	return res;
 }
 
+EMSCRIPTEN_KEEPALIVE const char * mono_wasm_method_get_name_ex (MonoMethod *method) {
+	const char *res;
+	MONO_ENTER_GC_UNSAFE;
+	res = mono_method_get_name (method);
+	// starts with .ctor or .cctor
+	if (mono_method_get_flags (method, NULL) & 0x0800 /* METHOD_ATTRIBUTE_SPECIAL_NAME */ && strlen (res) < 7) {
+ char *res_ex = (char *) malloc (128);
+ snprintf (res_ex, 128,"%s.%s", mono_class_get_name (mono_method_get_class (method)), res);
+ res = res_ex;
+	} else {
+ res = strdup (res);
+	}
+	MONO_EXIT_GC_UNSAFE;
+	return res;
+}
+
 EMSCRIPTEN_KEEPALIVE float mono_wasm_get_f32_unaligned (const float *src) {
 	return *src;
 }

src/mono/browser/runtime/es6/dotnet.es6.lib.js

@@ -90,6 +90,7 @@ function injectDependencies() {
  `enablePerfTracing: ${FEATURE_PERFTRACING ? "true" : "false"}, ` +
  `enableAotProfiler: ${ENABLE_AOT_PROFILER ? "true" : "false"}, ` +
  `enableBrowserProfiler: ${ENABLE_BROWSER_PROFILER ? "true" : "false"}, ` +
+ `enablePerfTracing: ${ENABLE_BROWSER_PROFILER ? "true" : "false"}, ` +
  `enableLogProfiler: ${ENABLE_LOG_PROFILER ? "true" : "false"}, ` +
  `runAOTCompilation: ${RUN_AOT_COMPILATION ? "true" : "false"}, ` +
  `wasmEnableThreads: ${USE_PTHREADS ? "true" : "false"}, ` +

src/mono/browser/runtime/exports-binding.ts

@@ -6,14 +6,14 @@ import WasmEnableThreads from "consts:wasmEnableThreads";
 import { mono_wasm_debugger_log, mono_wasm_add_dbg_command_received, mono_wasm_set_entrypoint_breakpoint, mono_wasm_fire_debugger_agent_message_with_data, mono_wasm_fire_debugger_agent_message_with_data_to_pause } from "./debug";
 import { mono_wasm_release_cs_owned_object } from "./gc-handles";
 import { mono_wasm_bind_js_import_ST, mono_wasm_invoke_js_function, mono_wasm_invoke_jsimport_MT, mono_wasm_invoke_jsimport_ST } from "./invoke-js";
-import { mono_interp_tier_prepare_jiterpreter, mono_jiterp_free_method_data_js } from "./jiterpreter";
+import { mono_interp_tier_prepare_jiterpreter, mono_wasm_free_method_data } from "./jiterpreter";
 import { mono_interp_jit_wasm_entry_trampoline, mono_interp_record_interp_entry } from "./jiterpreter-interp-entry";
 import { mono_interp_jit_wasm_jit_call_trampoline, mono_interp_invoke_wasm_jit_call_trampoline, mono_interp_flush_jitcall_queue } from "./jiterpreter-jit-call";
 import { mono_wasm_resolve_or_reject_promise } from "./marshal-to-js";
 import { mono_wasm_schedule_timer, schedule_background_exec } from "./scheduling";
 import { mono_wasm_asm_loaded } from "./startup";
 import { mono_log_warn, mono_wasm_console_clear, mono_wasm_trace_logger } from "./logging";
-import { mono_wasm_profiler_leave, mono_wasm_profiler_enter, ds_rt_websocket_close, ds_rt_websocket_create, ds_rt_websocket_poll, ds_rt_websocket_recv, ds_rt_websocket_send } from "./profiler";
+import { mono_wasm_profiler_record, mono_wasm_profiler_now, ds_rt_websocket_close, ds_rt_websocket_create, ds_rt_websocket_poll, ds_rt_websocket_recv, ds_rt_websocket_send } from "./profiler";
 import { mono_wasm_browser_entropy } from "./crypto";
 import { mono_wasm_cancel_promise } from "./cancelable-promise";
 
@@ -68,10 +68,10 @@ export const mono_wasm_imports = [
  mono_interp_jit_wasm_jit_call_trampoline,
  mono_interp_invoke_wasm_jit_call_trampoline,
  mono_interp_flush_jitcall_queue,
-mono_jiterp_free_method_data_js,
+mono_wasm_free_method_data,
 
-mono_wasm_profiler_enter,
-mono_wasm_profiler_leave,
+mono_wasm_profiler_now,
+mono_wasm_profiler_record,
 
  // driver.c
  mono_wasm_trace_logger,

src/mono/browser/runtime/jiterpreter-support.ts

@@ -1600,6 +1600,27 @@ export const _now = (globalThis.performance && globalThis.performance.now)
 
 let scratchBuffer: NativePointer = <any>0;
 
+export function append_profiler_event (builder: WasmBuilder, ip: MintOpcodePtr, opcode: MintOpcode) {
+ let event_name:string;
+ switch (opcode) {
+ case MintOpcode.MINT_PROF_ENTER:
+ event_name = "prof_enter";
+ break;
+ case MintOpcode.MINT_PROF_SAMPLEPOINT:
+ event_name = "prof_samplepoint";
+ break;
+ case MintOpcode.MINT_PROF_EXIT:
+ case MintOpcode.MINT_PROF_EXIT_VOID:
+ event_name = "prof_leave";
+ break;
+ default:
+ throw new Error(`Unimplemented profiler event ${opcode}`);
+ }
+ builder.local("frame");
+ builder.i32_const(ip);
+ builder.callImport(event_name);
+}
+
 export function append_safepoint (builder: WasmBuilder, ip: MintOpcodePtr) {
  // safepoints are never triggered in a single-threaded build
  if (!WasmEnableThreads)

src/mono/browser/runtime/jiterpreter-trace-generator.ts

@@ -28,6 +28,7 @@ import {
  try_append_memmove_fast, getOpcodeTableValue,
  getMemberOffset, isZeroPageReserved, CfgBranchType,
  append_safepoint, modifyCounter, simdFallbackCounters,
+ append_profiler_event,
 } from "./jiterpreter-support";
 import {
  sizeOfDataItem, sizeOfV128, sizeOfStackval,
@@ -1415,9 +1416,15 @@ export function generateWasmBody (
  }
 
  case MintOpcode.MINT_RETHROW:
+ ip = abort;
+ break;
+
+ // call C
+ case MintOpcode.MINT_PROF_ENTER:
+ case MintOpcode.MINT_PROF_SAMPLEPOINT:
  case MintOpcode.MINT_PROF_EXIT:
  case MintOpcode.MINT_PROF_EXIT_VOID:
-ip = abort;
+append_profiler_event(builder, ip, opcode);
  break;
 
  // Generating code for these is kind of complex due to the intersection of JS and int64,

src/mono/browser/runtime/jiterpreter.ts

@@ -26,6 +26,7 @@ import { mono_jiterp_free_method_data_interp_entry } from "./jiterpreter-interp-
 import { mono_jiterp_free_method_data_jit_call } from "./jiterpreter-jit-call";
 import { mono_log_error, mono_log_info, mono_log_warn } from "./logging";
 import { utf8ToString } from "./strings";
+import { mono_wasm_profiler_free_method } from "./profiler";
 
 // Controls miscellaneous diagnostic output.
 export const trace = 0;
@@ -298,6 +299,12 @@ function getTraceImports () {
  if (nullCheckValidation)
  traceImports.push(importDef("notnull", assert_not_null));
 
+ if (runtimeHelpers.emscriptenBuildOptions.enablePerfTracing) {
+ traceImports.push(importDef("prof_enter", getRawCwrap("mono_jiterp_prof_enter")));
+ traceImports.push(importDef("prof_samplepoint", getRawCwrap("mono_jiterp_prof_samplepoint")));
+ traceImports.push(importDef("prof_leave", getRawCwrap("mono_jiterp_prof_leave")));
+ }
+
  const pushMathOps = (list: string[], type: string) => {
  for (let i = 0; i < list.length; i++) {
  const mop = list[i];
@@ -579,6 +586,30 @@ function initialize_builder (builder: WasmBuilder) {
  },
  WasmValtype.void, true
  );
+ builder.defineType(
+ "prof_enter",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
+ builder.defineType(
+ "prof_samplepoint",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
+ builder.defineType(
+ "prof_leave",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
  builder.defineType(
  "hashcode",
  {
@@ -1050,9 +1081,13 @@ export function mono_interp_tier_prepare_jiterpreter (
 
 // NOTE: This will potentially be called once for every trace entry point
 // in a given method, not just once per method
-export function mono_jiterp_free_method_data_js (
+export function mono_wasm_free_method_data (
  method: MonoMethod, imethod: number, traceIndex: number
 ) {
+ if (runtimeHelpers.emscriptenBuildOptions.enablePerfTracing) {
+ mono_wasm_profiler_free_method(method);
+ }
+
  // TODO: Uninstall the trace function pointer from the function pointer table,
  // so that the compiled trace module can be freed by the browser eventually
  // Release the trace info object, if present

src/mono/browser/runtime/profiler.ts

@@ -7,6 +7,7 @@ import { ENVIRONMENT_IS_WEB, mono_assert, runtimeHelpers } from "./globals";
 import { MonoMethod, AOTProfilerOptions, BrowserProfilerOptions, LogProfilerOptions } from "./types/internal";
 import { profiler_c_functions as cwraps } from "./cwraps";
 import { utf8ToString } from "./strings";
+import { free } from "./memory";
 
 // Initialize the AOT profiler with OPTIONS.
 // Requires the AOT profiler to be linked into the app.
@@ -32,7 +33,13 @@ export function mono_wasm_init_browser_profiler (options: BrowserProfilerOptions
  mono_assert(runtimeHelpers.emscriptenBuildOptions.enableBrowserProfiler, "Browser profiler is not enabled, please use <WasmProfilers>browser;</WasmProfilers> in your project file.");
  if (options == null)
  options = {};
- const arg = "browser:";
+ let arg = "browser:";
+ if (typeof options.callSpec === "string") {
+ arg += `callspec=${options.callSpec},`;
+ }
+ if (typeof options.sampleIntervalMs === "number") {
+ arg += `interval=${options.sampleIntervalMs},`;
+ }
  cwraps.mono_wasm_profiler_init_browser(arg);
 }
 
@@ -76,6 +83,7 @@ export function startMeasure (): TimeStamp {
 
 export function endMeasure (start: TimeStamp, block: string, id?: string) {
  if (runtimeHelpers.enablePerfMeasure && start) {
+ // API is slightly different between web and Nodejs
  const options = ENVIRONMENT_IS_WEB
  ? { start: start as any }
  : { startTime: start as any };
@@ -84,28 +92,27 @@ export function endMeasure (start: TimeStamp, block: string, id?: string) {
  }
 }
 
-const stackFrames: number[] = [];
-export function mono_wasm_profiler_enter (): void {
- if (runtimeHelpers.enablePerfMeasure) {
- stackFrames.push(globalThis.performance.now());
- }
+export function mono_wasm_profiler_now (): number {
+ return globalThis.performance.now();
+}
+
+export function mono_wasm_profiler_free_method (method: MonoMethod): void {
+ methodNames.delete(method as any);
 }
 
 const methodNames: Map<number, string> = new Map();
-export function mono_wasm_profiler_leave (method: MonoMethod): void {
- if (runtimeHelpers.enablePerfMeasure) {
- const start = stackFrames.pop();
- const options = ENVIRONMENT_IS_WEB
- ? { start: start }
- : { startTime: start };
- let methodName = methodNames.get(method as any);
- if (!methodName) {
- const chars = cwraps.mono_wasm_method_get_name(method);
- methodName = utf8ToString(chars);
- methodNames.set(method as any, methodName);
- }
- globalThis.performance.measure(methodName, options);
+export function mono_wasm_profiler_record (method: MonoMethod, start: number): void {
+ const options = ENVIRONMENT_IS_WEB
+ ? { start: start }
+ : { startTime: start };
+ let methodName = methodNames.get(method as any);
+ if (!methodName) {
+ const chars = cwraps.mono_wasm_method_get_name_ex(method);
+ methodName = utf8ToString(chars);
+ methodNames.set(method as any, methodName);
+ free(chars as any);
  }
+ globalThis.performance.measure(methodName, options);
 }
 
 /* eslint-disable @typescript-eslint/no-unused-vars */

src/mono/browser/runtime/types/internal.ts

@@ -259,6 +259,12 @@ export type AOTProfilerOptions = {
 }
 
 export type BrowserProfilerOptions = {
+ sampleIntervalMs?: number, // default: 1000
+ /**
+ * See callspec in https://github.com/dotnet/runtime/blob/main/docs/design/mono/diagnostics-tracing.md#trace-monovm-profiler-events-during-startup
+ * When used together with Mono AOT, the callspec needs to match one in <WasmProfilers>browser:callspec=N:Sample;</WasmProfilers> in your project file.
+ */
+ callSpec?: string,
 }
 
 export type LogProfilerOptions = {

src/mono/mono/metadata/jit-icall-reg.h

@@ -250,6 +250,7 @@ MONO_JIT_ICALL (mono_ppc_throw_exception)	\
 MONO_JIT_ICALL (mono_profiler_raise_exception_clause) \
 MONO_JIT_ICALL (mono_profiler_raise_gc_allocation) \
 MONO_JIT_ICALL (mono_profiler_raise_method_enter) \
+MONO_JIT_ICALL (mono_profiler_raise_method_samplepoint) \
 MONO_JIT_ICALL (mono_profiler_raise_method_leave) \
 MONO_JIT_ICALL (mono_profiler_raise_method_tail_call) \
 MONO_JIT_ICALL (mono_resolve_generic_virtual_call) \
@@ -298,6 +299,7 @@ MONO_JIT_ICALL (mono_throw_platform_not_supported) \
 MONO_JIT_ICALL (mono_throw_invalid_program) \
 MONO_JIT_ICALL (mono_throw_type_load) \
 MONO_JIT_ICALL (mono_trace_enter_method) \
+MONO_JIT_ICALL (mono_trace_samplepoint_method) \
 MONO_JIT_ICALL (mono_trace_leave_method) \
 MONO_JIT_ICALL (mono_trace_tail_method) \
 MONO_JIT_ICALL (mono_upgrade_remote_class_wrapper) \

src/mono/browser/runtime/cwraps.ts

@@ -63,7 +63,6 @@ const fn_signatures: SigLine[] = [
  [() => !runtimeHelpers.emscriptenBuildOptions.enableAotProfiler, "mono_wasm_profiler_init_aot", "void", ["string"]],
  [() => !runtimeHelpers.emscriptenBuildOptions.enableBrowserProfiler, "mono_wasm_profiler_init_browser", "void", ["string"]],
  [() => !runtimeHelpers.emscriptenBuildOptions.enableLogProfiler, "mono_wasm_profiler_init_log", "void", ["string"]],
- [true, "mono_wasm_profiler_init_browser", "void", ["number"]],
  [false, "mono_wasm_exec_regression", "number", ["number", "string"]],
  [false, "mono_wasm_invoke_jsexport", "void", ["number", "number"]],
  [true, "mono_wasm_write_managed_pointer_unsafe", "void", ["number", "number"]],
@@ -73,6 +72,7 @@ const fn_signatures: SigLine[] = [
  [true, "mono_wasm_f64_to_i52", "number", ["number", "number"]],
  [true, "mono_wasm_f64_to_u52", "number", ["number", "number"]],
  [true, "mono_wasm_method_get_name", "number", ["number"]],
+ [true, "mono_wasm_method_get_name_ex", "number", ["number"]],
  [true, "mono_wasm_method_get_full_name", "number", ["number"]],
  [true, "mono_wasm_gc_lock", "void", []],
  [true, "mono_wasm_gc_unlock", "void", []],
@@ -131,6 +131,9 @@ const fn_signatures: SigLine[] = [
  [true, "mono_jiterp_end_catch", "void", []],
  [true, "mono_interp_pgo_load_table", "number", ["number", "number"]],
  [true, "mono_interp_pgo_save_table", "number", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_enter", "void", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_samplepoint", "void", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_leave", "void", ["number", "number"]],
 
  ...threading_cwraps,
 ];
@@ -193,6 +196,7 @@ export interface t_Cwraps {
  mono_wasm_f64_to_i52(destination: VoidPtr, value: number): I52Error;
  mono_wasm_f64_to_u52(destination: VoidPtr, value: number): I52Error;
  mono_wasm_method_get_name(method: MonoMethod): CharPtr;
+ mono_wasm_method_get_name_ex(method: MonoMethod): CharPtr;
  mono_wasm_method_get_full_name(method: MonoMethod): CharPtr;
  mono_wasm_gc_lock(): void;
  mono_wasm_gc_unlock(): void;

src/mono/browser/runtime/driver.c

@@ -534,6 +534,22 @@ EMSCRIPTEN_KEEPALIVE const char * mono_wasm_method_get_name (MonoMethod *method)
 	return res;
 }
 
+EMSCRIPTEN_KEEPALIVE const char * mono_wasm_method_get_name_ex (MonoMethod *method) {
+	const char *res;
+	MONO_ENTER_GC_UNSAFE;
+	res = mono_method_get_name (method);
+	// starts with .ctor or .cctor
+	if (mono_method_get_flags (method, NULL) & 0x0800 /* METHOD_ATTRIBUTE_SPECIAL_NAME */ && strlen (res) < 7) {
+ char *res_ex = (char *) malloc (128);
+ snprintf (res_ex, 128,"%s.%s", mono_class_get_name (mono_method_get_class (method)), res);
+ res = res_ex;
+	} else {
+ res = strdup (res);
+	}
+	MONO_EXIT_GC_UNSAFE;
+	return res;
+}
+
 EMSCRIPTEN_KEEPALIVE float mono_wasm_get_f32_unaligned (const float *src) {
 	return *src;
 }

src/mono/browser/runtime/es6/dotnet.es6.lib.js

@@ -90,6 +90,7 @@ function injectDependencies() {
  `enablePerfTracing: ${FEATURE_PERFTRACING ? "true" : "false"}, ` +
  `enableAotProfiler: ${ENABLE_AOT_PROFILER ? "true" : "false"}, ` +
  `enableBrowserProfiler: ${ENABLE_BROWSER_PROFILER ? "true" : "false"}, ` +
+ `enablePerfTracing: ${ENABLE_BROWSER_PROFILER ? "true" : "false"}, ` +
  `enableLogProfiler: ${ENABLE_LOG_PROFILER ? "true" : "false"}, ` +
  `runAOTCompilation: ${RUN_AOT_COMPILATION ? "true" : "false"}, ` +
  `wasmEnableThreads: ${USE_PTHREADS ? "true" : "false"}, ` +

src/mono/browser/runtime/exports-binding.ts

@@ -6,14 +6,14 @@ import WasmEnableThreads from "consts:wasmEnableThreads";
 import { mono_wasm_debugger_log, mono_wasm_add_dbg_command_received, mono_wasm_set_entrypoint_breakpoint, mono_wasm_fire_debugger_agent_message_with_data, mono_wasm_fire_debugger_agent_message_with_data_to_pause } from "./debug";
 import { mono_wasm_release_cs_owned_object } from "./gc-handles";
 import { mono_wasm_bind_js_import_ST, mono_wasm_invoke_js_function, mono_wasm_invoke_jsimport_MT, mono_wasm_invoke_jsimport_ST } from "./invoke-js";
-import { mono_interp_tier_prepare_jiterpreter, mono_jiterp_free_method_data_js } from "./jiterpreter";
+import { mono_interp_tier_prepare_jiterpreter, mono_wasm_free_method_data } from "./jiterpreter";
 import { mono_interp_jit_wasm_entry_trampoline, mono_interp_record_interp_entry } from "./jiterpreter-interp-entry";
 import { mono_interp_jit_wasm_jit_call_trampoline, mono_interp_invoke_wasm_jit_call_trampoline, mono_interp_flush_jitcall_queue } from "./jiterpreter-jit-call";
 import { mono_wasm_resolve_or_reject_promise } from "./marshal-to-js";
 import { mono_wasm_schedule_timer, schedule_background_exec } from "./scheduling";
 import { mono_wasm_asm_loaded } from "./startup";
 import { mono_log_warn, mono_wasm_console_clear, mono_wasm_trace_logger } from "./logging";
-import { mono_wasm_profiler_leave, mono_wasm_profiler_enter, ds_rt_websocket_close, ds_rt_websocket_create, ds_rt_websocket_poll, ds_rt_websocket_recv, ds_rt_websocket_send } from "./profiler";
+import { mono_wasm_profiler_record, mono_wasm_profiler_now, ds_rt_websocket_close, ds_rt_websocket_create, ds_rt_websocket_poll, ds_rt_websocket_recv, ds_rt_websocket_send } from "./profiler";
 import { mono_wasm_browser_entropy } from "./crypto";
 import { mono_wasm_cancel_promise } from "./cancelable-promise";
 
@@ -68,10 +68,10 @@ export const mono_wasm_imports = [
  mono_interp_jit_wasm_jit_call_trampoline,
  mono_interp_invoke_wasm_jit_call_trampoline,
  mono_interp_flush_jitcall_queue,
-mono_jiterp_free_method_data_js,
+mono_wasm_free_method_data,
 
-mono_wasm_profiler_enter,
-mono_wasm_profiler_leave,
+mono_wasm_profiler_now,
+mono_wasm_profiler_record,
 
  // driver.c
  mono_wasm_trace_logger,

src/mono/browser/runtime/jiterpreter-support.ts

@@ -1600,6 +1600,27 @@ export const _now = (globalThis.performance && globalThis.performance.now)
 
 let scratchBuffer: NativePointer = <any>0;
 
+export function append_profiler_event (builder: WasmBuilder, ip: MintOpcodePtr, opcode: MintOpcode) {
+ let event_name:string;
+ switch (opcode) {
+ case MintOpcode.MINT_PROF_ENTER:
+ event_name = "prof_enter";
+ break;
+ case MintOpcode.MINT_PROF_SAMPLEPOINT:
+ event_name = "prof_samplepoint";
+ break;
+ case MintOpcode.MINT_PROF_EXIT:
+ case MintOpcode.MINT_PROF_EXIT_VOID:
+ event_name = "prof_leave";
+ break;
+ default:
+ throw new Error(`Unimplemented profiler event ${opcode}`);
+ }
+ builder.local("frame");
+ builder.i32_const(ip);
+ builder.callImport(event_name);
+}
+
 export function append_safepoint (builder: WasmBuilder, ip: MintOpcodePtr) {
  // safepoints are never triggered in a single-threaded build
  if (!WasmEnableThreads)

src/mono/browser/runtime/jiterpreter-trace-generator.ts

@@ -28,6 +28,7 @@ import {
  try_append_memmove_fast, getOpcodeTableValue,
  getMemberOffset, isZeroPageReserved, CfgBranchType,
  append_safepoint, modifyCounter, simdFallbackCounters,
+ append_profiler_event,
 } from "./jiterpreter-support";
 import {
  sizeOfDataItem, sizeOfV128, sizeOfStackval,
@@ -1415,9 +1416,15 @@ export function generateWasmBody (
  }
 
  case MintOpcode.MINT_RETHROW:
+ ip = abort;
+ break;
+
+ // call C
+ case MintOpcode.MINT_PROF_ENTER:
+ case MintOpcode.MINT_PROF_SAMPLEPOINT:
  case MintOpcode.MINT_PROF_EXIT:
  case MintOpcode.MINT_PROF_EXIT_VOID:
-ip = abort;
+append_profiler_event(builder, ip, opcode);
  break;
 
  // Generating code for these is kind of complex due to the intersection of JS and int64,

src/mono/browser/runtime/jiterpreter.ts

@@ -26,6 +26,7 @@ import { mono_jiterp_free_method_data_interp_entry } from "./jiterpreter-interp-
 import { mono_jiterp_free_method_data_jit_call } from "./jiterpreter-jit-call";
 import { mono_log_error, mono_log_info, mono_log_warn } from "./logging";
 import { utf8ToString } from "./strings";
+import { mono_wasm_profiler_free_method } from "./profiler";
 
 // Controls miscellaneous diagnostic output.
 export const trace = 0;
@@ -298,6 +299,12 @@ function getTraceImports () {
  if (nullCheckValidation)
  traceImports.push(importDef("notnull", assert_not_null));
 
+ if (runtimeHelpers.emscriptenBuildOptions.enablePerfTracing) {
+ traceImports.push(importDef("prof_enter", getRawCwrap("mono_jiterp_prof_enter")));
+ traceImports.push(importDef("prof_samplepoint", getRawCwrap("mono_jiterp_prof_samplepoint")));
+ traceImports.push(importDef("prof_leave", getRawCwrap("mono_jiterp_prof_leave")));
+ }
+
  const pushMathOps = (list: string[], type: string) => {
  for (let i = 0; i < list.length; i++) {
  const mop = list[i];
@@ -579,6 +586,30 @@ function initialize_builder (builder: WasmBuilder) {
  },
  WasmValtype.void, true
  );
+ builder.defineType(
+ "prof_enter",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
+ builder.defineType(
+ "prof_samplepoint",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
+ builder.defineType(
+ "prof_leave",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
  builder.defineType(
  "hashcode",
  {
@@ -1050,9 +1081,13 @@ export function mono_interp_tier_prepare_jiterpreter (
 
 // NOTE: This will potentially be called once for every trace entry point
 // in a given method, not just once per method
-export function mono_jiterp_free_method_data_js (
+export function mono_wasm_free_method_data (
  method: MonoMethod, imethod: number, traceIndex: number
 ) {
+ if (runtimeHelpers.emscriptenBuildOptions.enablePerfTracing) {
+ mono_wasm_profiler_free_method(method);
+ }
+
  // TODO: Uninstall the trace function pointer from the function pointer table,
  // so that the compiled trace module can be freed by the browser eventually
  // Release the trace info object, if present

src/mono/browser/runtime/profiler.ts

@@ -7,6 +7,7 @@ import { ENVIRONMENT_IS_WEB, mono_assert, runtimeHelpers } from "./globals";
 import { MonoMethod, AOTProfilerOptions, BrowserProfilerOptions, LogProfilerOptions } from "./types/internal";
 import { profiler_c_functions as cwraps } from "./cwraps";
 import { utf8ToString } from "./strings";
+import { free } from "./memory";
 
 // Initialize the AOT profiler with OPTIONS.
 // Requires the AOT profiler to be linked into the app.
@@ -32,7 +33,13 @@ export function mono_wasm_init_browser_profiler (options: BrowserProfilerOptions
  mono_assert(runtimeHelpers.emscriptenBuildOptions.enableBrowserProfiler, "Browser profiler is not enabled, please use <WasmProfilers>browser;</WasmProfilers> in your project file.");
  if (options == null)
  options = {};
- const arg = "browser:";
+ let arg = "browser:";
+ if (typeof options.callSpec === "string") {
+ arg += `callspec=${options.callSpec},`;
+ }
+ if (typeof options.sampleIntervalMs === "number") {
+ arg += `interval=${options.sampleIntervalMs},`;
+ }
  cwraps.mono_wasm_profiler_init_browser(arg);
 }
 
@@ -76,6 +83,7 @@ export function startMeasure (): TimeStamp {
 
 export function endMeasure (start: TimeStamp, block: string, id?: string) {
  if (runtimeHelpers.enablePerfMeasure && start) {
+ // API is slightly different between web and Nodejs
  const options = ENVIRONMENT_IS_WEB
  ? { start: start as any }
  : { startTime: start as any };
@@ -84,28 +92,27 @@ export function endMeasure (start: TimeStamp, block: string, id?: string) {
  }
 }
 
-const stackFrames: number[] = [];
-export function mono_wasm_profiler_enter (): void {
- if (runtimeHelpers.enablePerfMeasure) {
- stackFrames.push(globalThis.performance.now());
- }
+export function mono_wasm_profiler_now (): number {
+ return globalThis.performance.now();
+}
+
+export function mono_wasm_profiler_free_method (method: MonoMethod): void {
+ methodNames.delete(method as any);
 }
 
 const methodNames: Map<number, string> = new Map();
-export function mono_wasm_profiler_leave (method: MonoMethod): void {
- if (runtimeHelpers.enablePerfMeasure) {
- const start = stackFrames.pop();
- const options = ENVIRONMENT_IS_WEB
- ? { start: start }
- : { startTime: start };
- let methodName = methodNames.get(method as any);
- if (!methodName) {
- const chars = cwraps.mono_wasm_method_get_name(method);
- methodName = utf8ToString(chars);
- methodNames.set(method as any, methodName);
- }
- globalThis.performance.measure(methodName, options);
+export function mono_wasm_profiler_record (method: MonoMethod, start: number): void {
+ const options = ENVIRONMENT_IS_WEB
+ ? { start: start }
+ : { startTime: start };
+ let methodName = methodNames.get(method as any);
+ if (!methodName) {
+ const chars = cwraps.mono_wasm_method_get_name_ex(method);
+ methodName = utf8ToString(chars);
+ methodNames.set(method as any, methodName);
+ free(chars as any);
  }
+ globalThis.performance.measure(methodName, options);
 }
 
 /* eslint-disable @typescript-eslint/no-unused-vars */

src/mono/browser/runtime/types/internal.ts

@@ -259,6 +259,12 @@ export type AOTProfilerOptions = {
 }
 
 export type BrowserProfilerOptions = {
+ sampleIntervalMs?: number, // default: 1000
+ /**
+ * See callspec in https://github.com/dotnet/runtime/blob/main/docs/design/mono/diagnostics-tracing.md#trace-monovm-profiler-events-during-startup
+ * When used together with Mono AOT, the callspec needs to match one in <WasmProfilers>browser:callspec=N:Sample;</WasmProfilers> in your project file.
+ */
+ callSpec?: string,
 }
 
 export type LogProfilerOptions = {

src/mono/mono/metadata/jit-icall-reg.h

@@ -250,6 +250,7 @@ MONO_JIT_ICALL (mono_ppc_throw_exception)	\
 MONO_JIT_ICALL (mono_profiler_raise_exception_clause) \
 MONO_JIT_ICALL (mono_profiler_raise_gc_allocation) \
 MONO_JIT_ICALL (mono_profiler_raise_method_enter) \
+MONO_JIT_ICALL (mono_profiler_raise_method_samplepoint) \
 MONO_JIT_ICALL (mono_profiler_raise_method_leave) \
 MONO_JIT_ICALL (mono_profiler_raise_method_tail_call) \
 MONO_JIT_ICALL (mono_resolve_generic_virtual_call) \
@@ -298,6 +299,7 @@ MONO_JIT_ICALL (mono_throw_platform_not_supported) \
 MONO_JIT_ICALL (mono_throw_invalid_program) \
 MONO_JIT_ICALL (mono_throw_type_load) \
 MONO_JIT_ICALL (mono_trace_enter_method) \
+MONO_JIT_ICALL (mono_trace_samplepoint_method) \
 MONO_JIT_ICALL (mono_trace_leave_method) \
 MONO_JIT_ICALL (mono_trace_tail_method) \
 MONO_JIT_ICALL (mono_upgrade_remote_class_wrapper) \

src/mono/browser/runtime/cwraps.ts

@@ -63,7 +63,6 @@ const fn_signatures: SigLine[] = [
  [() => !runtimeHelpers.emscriptenBuildOptions.enableAotProfiler, "mono_wasm_profiler_init_aot", "void", ["string"]],
  [() => !runtimeHelpers.emscriptenBuildOptions.enableBrowserProfiler, "mono_wasm_profiler_init_browser", "void", ["string"]],
  [() => !runtimeHelpers.emscriptenBuildOptions.enableLogProfiler, "mono_wasm_profiler_init_log", "void", ["string"]],
- [true, "mono_wasm_profiler_init_browser", "void", ["number"]],
  [false, "mono_wasm_exec_regression", "number", ["number", "string"]],
  [false, "mono_wasm_invoke_jsexport", "void", ["number", "number"]],
  [true, "mono_wasm_write_managed_pointer_unsafe", "void", ["number", "number"]],
@@ -73,6 +72,7 @@ const fn_signatures: SigLine[] = [
  [true, "mono_wasm_f64_to_i52", "number", ["number", "number"]],
  [true, "mono_wasm_f64_to_u52", "number", ["number", "number"]],
  [true, "mono_wasm_method_get_name", "number", ["number"]],
+ [true, "mono_wasm_method_get_name_ex", "number", ["number"]],
  [true, "mono_wasm_method_get_full_name", "number", ["number"]],
  [true, "mono_wasm_gc_lock", "void", []],
  [true, "mono_wasm_gc_unlock", "void", []],
@@ -131,6 +131,9 @@ const fn_signatures: SigLine[] = [
  [true, "mono_jiterp_end_catch", "void", []],
  [true, "mono_interp_pgo_load_table", "number", ["number", "number"]],
  [true, "mono_interp_pgo_save_table", "number", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_enter", "void", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_samplepoint", "void", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_leave", "void", ["number", "number"]],
 
  ...threading_cwraps,
 ];
@@ -193,6 +196,7 @@ export interface t_Cwraps {
  mono_wasm_f64_to_i52(destination: VoidPtr, value: number): I52Error;
  mono_wasm_f64_to_u52(destination: VoidPtr, value: number): I52Error;
  mono_wasm_method_get_name(method: MonoMethod): CharPtr;
+ mono_wasm_method_get_name_ex(method: MonoMethod): CharPtr;
  mono_wasm_method_get_full_name(method: MonoMethod): CharPtr;
  mono_wasm_gc_lock(): void;
  mono_wasm_gc_unlock(): void;

src/mono/browser/runtime/driver.c

@@ -534,6 +534,22 @@ EMSCRIPTEN_KEEPALIVE const char * mono_wasm_method_get_name (MonoMethod *method)
 	return res;
 }
 
+EMSCRIPTEN_KEEPALIVE const char * mono_wasm_method_get_name_ex (MonoMethod *method) {
+	const char *res;
+	MONO_ENTER_GC_UNSAFE;
+	res = mono_method_get_name (method);
+	// starts with .ctor or .cctor
+	if (mono_method_get_flags (method, NULL) & 0x0800 /* METHOD_ATTRIBUTE_SPECIAL_NAME */ && strlen (res) < 7) {
+ char *res_ex = (char *) malloc (128);
+ snprintf (res_ex, 128,"%s.%s", mono_class_get_name (mono_method_get_class (method)), res);
+ res = res_ex;
+	} else {
+ res = strdup (res);
+	}
+	MONO_EXIT_GC_UNSAFE;
+	return res;
+}
+
 EMSCRIPTEN_KEEPALIVE float mono_wasm_get_f32_unaligned (const float *src) {
 	return *src;
 }

src/mono/browser/runtime/es6/dotnet.es6.lib.js

@@ -90,6 +90,7 @@ function injectDependencies() {
  `enablePerfTracing: ${FEATURE_PERFTRACING ? "true" : "false"}, ` +
  `enableAotProfiler: ${ENABLE_AOT_PROFILER ? "true" : "false"}, ` +
  `enableBrowserProfiler: ${ENABLE_BROWSER_PROFILER ? "true" : "false"}, ` +
+ `enablePerfTracing: ${ENABLE_BROWSER_PROFILER ? "true" : "false"}, ` +
  `enableLogProfiler: ${ENABLE_LOG_PROFILER ? "true" : "false"}, ` +
  `runAOTCompilation: ${RUN_AOT_COMPILATION ? "true" : "false"}, ` +
  `wasmEnableThreads: ${USE_PTHREADS ? "true" : "false"}, ` +

src/mono/browser/runtime/exports-binding.ts

@@ -6,14 +6,14 @@ import WasmEnableThreads from "consts:wasmEnableThreads";
 import { mono_wasm_debugger_log, mono_wasm_add_dbg_command_received, mono_wasm_set_entrypoint_breakpoint, mono_wasm_fire_debugger_agent_message_with_data, mono_wasm_fire_debugger_agent_message_with_data_to_pause } from "./debug";
 import { mono_wasm_release_cs_owned_object } from "./gc-handles";
 import { mono_wasm_bind_js_import_ST, mono_wasm_invoke_js_function, mono_wasm_invoke_jsimport_MT, mono_wasm_invoke_jsimport_ST } from "./invoke-js";
-import { mono_interp_tier_prepare_jiterpreter, mono_jiterp_free_method_data_js } from "./jiterpreter";
+import { mono_interp_tier_prepare_jiterpreter, mono_wasm_free_method_data } from "./jiterpreter";
 import { mono_interp_jit_wasm_entry_trampoline, mono_interp_record_interp_entry } from "./jiterpreter-interp-entry";
 import { mono_interp_jit_wasm_jit_call_trampoline, mono_interp_invoke_wasm_jit_call_trampoline, mono_interp_flush_jitcall_queue } from "./jiterpreter-jit-call";
 import { mono_wasm_resolve_or_reject_promise } from "./marshal-to-js";
 import { mono_wasm_schedule_timer, schedule_background_exec } from "./scheduling";
 import { mono_wasm_asm_loaded } from "./startup";
 import { mono_log_warn, mono_wasm_console_clear, mono_wasm_trace_logger } from "./logging";
-import { mono_wasm_profiler_leave, mono_wasm_profiler_enter, ds_rt_websocket_close, ds_rt_websocket_create, ds_rt_websocket_poll, ds_rt_websocket_recv, ds_rt_websocket_send } from "./profiler";
+import { mono_wasm_profiler_record, mono_wasm_profiler_now, ds_rt_websocket_close, ds_rt_websocket_create, ds_rt_websocket_poll, ds_rt_websocket_recv, ds_rt_websocket_send } from "./profiler";
 import { mono_wasm_browser_entropy } from "./crypto";
 import { mono_wasm_cancel_promise } from "./cancelable-promise";
 
@@ -68,10 +68,10 @@ export const mono_wasm_imports = [
  mono_interp_jit_wasm_jit_call_trampoline,
  mono_interp_invoke_wasm_jit_call_trampoline,
  mono_interp_flush_jitcall_queue,
-mono_jiterp_free_method_data_js,
+mono_wasm_free_method_data,
 
-mono_wasm_profiler_enter,
-mono_wasm_profiler_leave,
+mono_wasm_profiler_now,
+mono_wasm_profiler_record,
 
  // driver.c
  mono_wasm_trace_logger,

src/mono/browser/runtime/jiterpreter-support.ts

@@ -1600,6 +1600,27 @@ export const _now = (globalThis.performance && globalThis.performance.now)
 
 let scratchBuffer: NativePointer = <any>0;
 
+export function append_profiler_event (builder: WasmBuilder, ip: MintOpcodePtr, opcode: MintOpcode) {
+ let event_name:string;
+ switch (opcode) {
+ case MintOpcode.MINT_PROF_ENTER:
+ event_name = "prof_enter";
+ break;
+ case MintOpcode.MINT_PROF_SAMPLEPOINT:
+ event_name = "prof_samplepoint";
+ break;
+ case MintOpcode.MINT_PROF_EXIT:
+ case MintOpcode.MINT_PROF_EXIT_VOID:
+ event_name = "prof_leave";
+ break;
+ default:
+ throw new Error(`Unimplemented profiler event ${opcode}`);
+ }
+ builder.local("frame");
+ builder.i32_const(ip);
+ builder.callImport(event_name);
+}
+
 export function append_safepoint (builder: WasmBuilder, ip: MintOpcodePtr) {
  // safepoints are never triggered in a single-threaded build
  if (!WasmEnableThreads)

src/mono/browser/runtime/jiterpreter-trace-generator.ts

@@ -28,6 +28,7 @@ import {
  try_append_memmove_fast, getOpcodeTableValue,
  getMemberOffset, isZeroPageReserved, CfgBranchType,
  append_safepoint, modifyCounter, simdFallbackCounters,
+ append_profiler_event,
 } from "./jiterpreter-support";
 import {
  sizeOfDataItem, sizeOfV128, sizeOfStackval,
@@ -1415,9 +1416,15 @@ export function generateWasmBody (
  }
 
  case MintOpcode.MINT_RETHROW:
+ ip = abort;
+ break;
+
+ // call C
+ case MintOpcode.MINT_PROF_ENTER:
+ case MintOpcode.MINT_PROF_SAMPLEPOINT:
  case MintOpcode.MINT_PROF_EXIT:
  case MintOpcode.MINT_PROF_EXIT_VOID:
-ip = abort;
+append_profiler_event(builder, ip, opcode);
  break;
 
  // Generating code for these is kind of complex due to the intersection of JS and int64,

src/mono/browser/runtime/jiterpreter.ts

@@ -26,6 +26,7 @@ import { mono_jiterp_free_method_data_interp_entry } from "./jiterpreter-interp-
 import { mono_jiterp_free_method_data_jit_call } from "./jiterpreter-jit-call";
 import { mono_log_error, mono_log_info, mono_log_warn } from "./logging";
 import { utf8ToString } from "./strings";
+import { mono_wasm_profiler_free_method } from "./profiler";
 
 // Controls miscellaneous diagnostic output.
 export const trace = 0;
@@ -298,6 +299,12 @@ function getTraceImports () {
  if (nullCheckValidation)
  traceImports.push(importDef("notnull", assert_not_null));
 
+ if (runtimeHelpers.emscriptenBuildOptions.enablePerfTracing) {
+ traceImports.push(importDef("prof_enter", getRawCwrap("mono_jiterp_prof_enter")));
+ traceImports.push(importDef("prof_samplepoint", getRawCwrap("mono_jiterp_prof_samplepoint")));
+ traceImports.push(importDef("prof_leave", getRawCwrap("mono_jiterp_prof_leave")));
+ }
+
  const pushMathOps = (list: string[], type: string) => {
  for (let i = 0; i < list.length; i++) {
  const mop = list[i];
@@ -579,6 +586,30 @@ function initialize_builder (builder: WasmBuilder) {
  },
  WasmValtype.void, true
  );
+ builder.defineType(
+ "prof_enter",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
+ builder.defineType(
+ "prof_samplepoint",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
+ builder.defineType(
+ "prof_leave",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
  builder.defineType(
  "hashcode",
  {
@@ -1050,9 +1081,13 @@ export function mono_interp_tier_prepare_jiterpreter (
 
 // NOTE: This will potentially be called once for every trace entry point
 // in a given method, not just once per method
-export function mono_jiterp_free_method_data_js (
+export function mono_wasm_free_method_data (
  method: MonoMethod, imethod: number, traceIndex: number
 ) {
+ if (runtimeHelpers.emscriptenBuildOptions.enablePerfTracing) {
+ mono_wasm_profiler_free_method(method);
+ }
+
  // TODO: Uninstall the trace function pointer from the function pointer table,
  // so that the compiled trace module can be freed by the browser eventually
  // Release the trace info object, if present

src/mono/browser/runtime/profiler.ts

@@ -7,6 +7,7 @@ import { ENVIRONMENT_IS_WEB, mono_assert, runtimeHelpers } from "./globals";
 import { MonoMethod, AOTProfilerOptions, BrowserProfilerOptions, LogProfilerOptions } from "./types/internal";
 import { profiler_c_functions as cwraps } from "./cwraps";
 import { utf8ToString } from "./strings";
+import { free } from "./memory";
 
 // Initialize the AOT profiler with OPTIONS.
 // Requires the AOT profiler to be linked into the app.
@@ -32,7 +33,13 @@ export function mono_wasm_init_browser_profiler (options: BrowserProfilerOptions
  mono_assert(runtimeHelpers.emscriptenBuildOptions.enableBrowserProfiler, "Browser profiler is not enabled, please use <WasmProfilers>browser;</WasmProfilers> in your project file.");
  if (options == null)
  options = {};
- const arg = "browser:";
+ let arg = "browser:";
+ if (typeof options.callSpec === "string") {
+ arg += `callspec=${options.callSpec},`;
+ }
+ if (typeof options.sampleIntervalMs === "number") {
+ arg += `interval=${options.sampleIntervalMs},`;
+ }
  cwraps.mono_wasm_profiler_init_browser(arg);
 }
 
@@ -76,6 +83,7 @@ export function startMeasure (): TimeStamp {
 
 export function endMeasure (start: TimeStamp, block: string, id?: string) {
  if (runtimeHelpers.enablePerfMeasure && start) {
+ // API is slightly different between web and Nodejs
  const options = ENVIRONMENT_IS_WEB
  ? { start: start as any }
  : { startTime: start as any };
@@ -84,28 +92,27 @@ export function endMeasure (start: TimeStamp, block: string, id?: string) {
  }
 }
 
-const stackFrames: number[] = [];
-export function mono_wasm_profiler_enter (): void {
- if (runtimeHelpers.enablePerfMeasure) {
- stackFrames.push(globalThis.performance.now());
- }
+export function mono_wasm_profiler_now (): number {
+ return globalThis.performance.now();
+}
+
+export function mono_wasm_profiler_free_method (method: MonoMethod): void {
+ methodNames.delete(method as any);
 }
 
 const methodNames: Map<number, string> = new Map();
-export function mono_wasm_profiler_leave (method: MonoMethod): void {
- if (runtimeHelpers.enablePerfMeasure) {
- const start = stackFrames.pop();
- const options = ENVIRONMENT_IS_WEB
- ? { start: start }
- : { startTime: start };
- let methodName = methodNames.get(method as any);
- if (!methodName) {
- const chars = cwraps.mono_wasm_method_get_name(method);
- methodName = utf8ToString(chars);
- methodNames.set(method as any, methodName);
- }
- globalThis.performance.measure(methodName, options);
+export function mono_wasm_profiler_record (method: MonoMethod, start: number): void {
+ const options = ENVIRONMENT_IS_WEB
+ ? { start: start }
+ : { startTime: start };
+ let methodName = methodNames.get(method as any);
+ if (!methodName) {
+ const chars = cwraps.mono_wasm_method_get_name_ex(method);
+ methodName = utf8ToString(chars);
+ methodNames.set(method as any, methodName);
+ free(chars as any);
  }
+ globalThis.performance.measure(methodName, options);
 }
 
 /* eslint-disable @typescript-eslint/no-unused-vars */

src/mono/browser/runtime/types/internal.ts

@@ -259,6 +259,12 @@ export type AOTProfilerOptions = {
 }
 
 export type BrowserProfilerOptions = {
+ sampleIntervalMs?: number, // default: 1000
+ /**
+ * See callspec in https://github.com/dotnet/runtime/blob/main/docs/design/mono/diagnostics-tracing.md#trace-monovm-profiler-events-during-startup
+ * When used together with Mono AOT, the callspec needs to match one in <WasmProfilers>browser:callspec=N:Sample;</WasmProfilers> in your project file.
+ */
+ callSpec?: string,
 }
 
 export type LogProfilerOptions = {

src/mono/mono/metadata/jit-icall-reg.h

@@ -250,6 +250,7 @@ MONO_JIT_ICALL (mono_ppc_throw_exception)	\
 MONO_JIT_ICALL (mono_profiler_raise_exception_clause) \
 MONO_JIT_ICALL (mono_profiler_raise_gc_allocation) \
 MONO_JIT_ICALL (mono_profiler_raise_method_enter) \
+MONO_JIT_ICALL (mono_profiler_raise_method_samplepoint) \
 MONO_JIT_ICALL (mono_profiler_raise_method_leave) \
 MONO_JIT_ICALL (mono_profiler_raise_method_tail_call) \
 MONO_JIT_ICALL (mono_resolve_generic_virtual_call) \
@@ -298,6 +299,7 @@ MONO_JIT_ICALL (mono_throw_platform_not_supported) \
 MONO_JIT_ICALL (mono_throw_invalid_program) \
 MONO_JIT_ICALL (mono_throw_type_load) \
 MONO_JIT_ICALL (mono_trace_enter_method) \
+MONO_JIT_ICALL (mono_trace_samplepoint_method) \
 MONO_JIT_ICALL (mono_trace_leave_method) \
 MONO_JIT_ICALL (mono_trace_tail_method) \
 MONO_JIT_ICALL (mono_upgrade_remote_class_wrapper) \

src/mono/browser/runtime/cwraps.ts

@@ -63,7 +63,6 @@ const fn_signatures: SigLine[] = [
  [() => !runtimeHelpers.emscriptenBuildOptions.enableAotProfiler, "mono_wasm_profiler_init_aot", "void", ["string"]],
  [() => !runtimeHelpers.emscriptenBuildOptions.enableBrowserProfiler, "mono_wasm_profiler_init_browser", "void", ["string"]],
  [() => !runtimeHelpers.emscriptenBuildOptions.enableLogProfiler, "mono_wasm_profiler_init_log", "void", ["string"]],
- [true, "mono_wasm_profiler_init_browser", "void", ["number"]],
  [false, "mono_wasm_exec_regression", "number", ["number", "string"]],
  [false, "mono_wasm_invoke_jsexport", "void", ["number", "number"]],
  [true, "mono_wasm_write_managed_pointer_unsafe", "void", ["number", "number"]],
@@ -73,6 +72,7 @@ const fn_signatures: SigLine[] = [
  [true, "mono_wasm_f64_to_i52", "number", ["number", "number"]],
  [true, "mono_wasm_f64_to_u52", "number", ["number", "number"]],
  [true, "mono_wasm_method_get_name", "number", ["number"]],
+ [true, "mono_wasm_method_get_name_ex", "number", ["number"]],
  [true, "mono_wasm_method_get_full_name", "number", ["number"]],
  [true, "mono_wasm_gc_lock", "void", []],
  [true, "mono_wasm_gc_unlock", "void", []],
@@ -131,6 +131,9 @@ const fn_signatures: SigLine[] = [
  [true, "mono_jiterp_end_catch", "void", []],
  [true, "mono_interp_pgo_load_table", "number", ["number", "number"]],
  [true, "mono_interp_pgo_save_table", "number", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_enter", "void", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_samplepoint", "void", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_leave", "void", ["number", "number"]],
 
  ...threading_cwraps,
 ];
@@ -193,6 +196,7 @@ export interface t_Cwraps {
  mono_wasm_f64_to_i52(destination: VoidPtr, value: number): I52Error;
  mono_wasm_f64_to_u52(destination: VoidPtr, value: number): I52Error;
  mono_wasm_method_get_name(method: MonoMethod): CharPtr;
+ mono_wasm_method_get_name_ex(method: MonoMethod): CharPtr;
  mono_wasm_method_get_full_name(method: MonoMethod): CharPtr;
  mono_wasm_gc_lock(): void;
  mono_wasm_gc_unlock(): void;

src/mono/browser/runtime/driver.c

@@ -534,6 +534,22 @@ EMSCRIPTEN_KEEPALIVE const char * mono_wasm_method_get_name (MonoMethod *method)
 	return res;
 }
 
+EMSCRIPTEN_KEEPALIVE const char * mono_wasm_method_get_name_ex (MonoMethod *method) {
+	const char *res;
+	MONO_ENTER_GC_UNSAFE;
+	res = mono_method_get_name (method);
+	// starts with .ctor or .cctor
+	if (mono_method_get_flags (method, NULL) & 0x0800 /* METHOD_ATTRIBUTE_SPECIAL_NAME */ && strlen (res) < 7) {
+ char *res_ex = (char *) malloc (128);
+ snprintf (res_ex, 128,"%s.%s", mono_class_get_name (mono_method_get_class (method)), res);
+ res = res_ex;
+	} else {
+ res = strdup (res);
+	}
+	MONO_EXIT_GC_UNSAFE;
+	return res;
+}
+
 EMSCRIPTEN_KEEPALIVE float mono_wasm_get_f32_unaligned (const float *src) {
 	return *src;
 }

src/mono/browser/runtime/es6/dotnet.es6.lib.js

@@ -90,6 +90,7 @@ function injectDependencies() {
  `enablePerfTracing: ${FEATURE_PERFTRACING ? "true" : "false"}, ` +
  `enableAotProfiler: ${ENABLE_AOT_PROFILER ? "true" : "false"}, ` +
  `enableBrowserProfiler: ${ENABLE_BROWSER_PROFILER ? "true" : "false"}, ` +
+ `enablePerfTracing: ${ENABLE_BROWSER_PROFILER ? "true" : "false"}, ` +
  `enableLogProfiler: ${ENABLE_LOG_PROFILER ? "true" : "false"}, ` +
  `runAOTCompilation: ${RUN_AOT_COMPILATION ? "true" : "false"}, ` +
  `wasmEnableThreads: ${USE_PTHREADS ? "true" : "false"}, ` +

src/mono/browser/runtime/exports-binding.ts

@@ -6,14 +6,14 @@ import WasmEnableThreads from "consts:wasmEnableThreads";
 import { mono_wasm_debugger_log, mono_wasm_add_dbg_command_received, mono_wasm_set_entrypoint_breakpoint, mono_wasm_fire_debugger_agent_message_with_data, mono_wasm_fire_debugger_agent_message_with_data_to_pause } from "./debug";
 import { mono_wasm_release_cs_owned_object } from "./gc-handles";
 import { mono_wasm_bind_js_import_ST, mono_wasm_invoke_js_function, mono_wasm_invoke_jsimport_MT, mono_wasm_invoke_jsimport_ST } from "./invoke-js";
-import { mono_interp_tier_prepare_jiterpreter, mono_jiterp_free_method_data_js } from "./jiterpreter";
+import { mono_interp_tier_prepare_jiterpreter, mono_wasm_free_method_data } from "./jiterpreter";
 import { mono_interp_jit_wasm_entry_trampoline, mono_interp_record_interp_entry } from "./jiterpreter-interp-entry";
 import { mono_interp_jit_wasm_jit_call_trampoline, mono_interp_invoke_wasm_jit_call_trampoline, mono_interp_flush_jitcall_queue } from "./jiterpreter-jit-call";
 import { mono_wasm_resolve_or_reject_promise } from "./marshal-to-js";
 import { mono_wasm_schedule_timer, schedule_background_exec } from "./scheduling";
 import { mono_wasm_asm_loaded } from "./startup";
 import { mono_log_warn, mono_wasm_console_clear, mono_wasm_trace_logger } from "./logging";
-import { mono_wasm_profiler_leave, mono_wasm_profiler_enter, ds_rt_websocket_close, ds_rt_websocket_create, ds_rt_websocket_poll, ds_rt_websocket_recv, ds_rt_websocket_send } from "./profiler";
+import { mono_wasm_profiler_record, mono_wasm_profiler_now, ds_rt_websocket_close, ds_rt_websocket_create, ds_rt_websocket_poll, ds_rt_websocket_recv, ds_rt_websocket_send } from "./profiler";
 import { mono_wasm_browser_entropy } from "./crypto";
 import { mono_wasm_cancel_promise } from "./cancelable-promise";
 
@@ -68,10 +68,10 @@ export const mono_wasm_imports = [
  mono_interp_jit_wasm_jit_call_trampoline,
  mono_interp_invoke_wasm_jit_call_trampoline,
  mono_interp_flush_jitcall_queue,
-mono_jiterp_free_method_data_js,
+mono_wasm_free_method_data,
 
-mono_wasm_profiler_enter,
-mono_wasm_profiler_leave,
+mono_wasm_profiler_now,
+mono_wasm_profiler_record,
 
  // driver.c
  mono_wasm_trace_logger,

src/mono/browser/runtime/jiterpreter-support.ts

@@ -1600,6 +1600,27 @@ export const _now = (globalThis.performance && globalThis.performance.now)
 
 let scratchBuffer: NativePointer = <any>0;
 
+export function append_profiler_event (builder: WasmBuilder, ip: MintOpcodePtr, opcode: MintOpcode) {
+ let event_name:string;
+ switch (opcode) {
+ case MintOpcode.MINT_PROF_ENTER:
+ event_name = "prof_enter";
+ break;
+ case MintOpcode.MINT_PROF_SAMPLEPOINT:
+ event_name = "prof_samplepoint";
+ break;
+ case MintOpcode.MINT_PROF_EXIT:
+ case MintOpcode.MINT_PROF_EXIT_VOID:
+ event_name = "prof_leave";
+ break;
+ default:
+ throw new Error(`Unimplemented profiler event ${opcode}`);
+ }
+ builder.local("frame");
+ builder.i32_const(ip);
+ builder.callImport(event_name);
+}
+
 export function append_safepoint (builder: WasmBuilder, ip: MintOpcodePtr) {
  // safepoints are never triggered in a single-threaded build
  if (!WasmEnableThreads)

src/mono/browser/runtime/jiterpreter-trace-generator.ts

@@ -28,6 +28,7 @@ import {
  try_append_memmove_fast, getOpcodeTableValue,
  getMemberOffset, isZeroPageReserved, CfgBranchType,
  append_safepoint, modifyCounter, simdFallbackCounters,
+ append_profiler_event,
 } from "./jiterpreter-support";
 import {
  sizeOfDataItem, sizeOfV128, sizeOfStackval,
@@ -1415,9 +1416,15 @@ export function generateWasmBody (
  }
 
  case MintOpcode.MINT_RETHROW:
+ ip = abort;
+ break;
+
+ // call C
+ case MintOpcode.MINT_PROF_ENTER:
+ case MintOpcode.MINT_PROF_SAMPLEPOINT:
  case MintOpcode.MINT_PROF_EXIT:
  case MintOpcode.MINT_PROF_EXIT_VOID:
-ip = abort;
+append_profiler_event(builder, ip, opcode);
  break;
 
  // Generating code for these is kind of complex due to the intersection of JS and int64,

src/mono/browser/runtime/jiterpreter.ts

@@ -26,6 +26,7 @@ import { mono_jiterp_free_method_data_interp_entry } from "./jiterpreter-interp-
 import { mono_jiterp_free_method_data_jit_call } from "./jiterpreter-jit-call";
 import { mono_log_error, mono_log_info, mono_log_warn } from "./logging";
 import { utf8ToString } from "./strings";
+import { mono_wasm_profiler_free_method } from "./profiler";
 
 // Controls miscellaneous diagnostic output.
 export const trace = 0;
@@ -298,6 +299,12 @@ function getTraceImports () {
  if (nullCheckValidation)
  traceImports.push(importDef("notnull", assert_not_null));
 
+ if (runtimeHelpers.emscriptenBuildOptions.enablePerfTracing) {
+ traceImports.push(importDef("prof_enter", getRawCwrap("mono_jiterp_prof_enter")));
+ traceImports.push(importDef("prof_samplepoint", getRawCwrap("mono_jiterp_prof_samplepoint")));
+ traceImports.push(importDef("prof_leave", getRawCwrap("mono_jiterp_prof_leave")));
+ }
+
  const pushMathOps = (list: string[], type: string) => {
  for (let i = 0; i < list.length; i++) {
  const mop = list[i];
@@ -579,6 +586,30 @@ function initialize_builder (builder: WasmBuilder) {
  },
  WasmValtype.void, true
  );
+ builder.defineType(
+ "prof_enter",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
+ builder.defineType(
+ "prof_samplepoint",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
+ builder.defineType(
+ "prof_leave",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
  builder.defineType(
  "hashcode",
  {
@@ -1050,9 +1081,13 @@ export function mono_interp_tier_prepare_jiterpreter (
 
 // NOTE: This will potentially be called once for every trace entry point
 // in a given method, not just once per method
-export function mono_jiterp_free_method_data_js (
+export function mono_wasm_free_method_data (
  method: MonoMethod, imethod: number, traceIndex: number
 ) {
+ if (runtimeHelpers.emscriptenBuildOptions.enablePerfTracing) {
+ mono_wasm_profiler_free_method(method);
+ }
+
  // TODO: Uninstall the trace function pointer from the function pointer table,
  // so that the compiled trace module can be freed by the browser eventually
  // Release the trace info object, if present

src/mono/browser/runtime/profiler.ts

@@ -7,6 +7,7 @@ import { ENVIRONMENT_IS_WEB, mono_assert, runtimeHelpers } from "./globals";
 import { MonoMethod, AOTProfilerOptions, BrowserProfilerOptions, LogProfilerOptions } from "./types/internal";
 import { profiler_c_functions as cwraps } from "./cwraps";
 import { utf8ToString } from "./strings";
+import { free } from "./memory";
 
 // Initialize the AOT profiler with OPTIONS.
 // Requires the AOT profiler to be linked into the app.
@@ -32,7 +33,13 @@ export function mono_wasm_init_browser_profiler (options: BrowserProfilerOptions
  mono_assert(runtimeHelpers.emscriptenBuildOptions.enableBrowserProfiler, "Browser profiler is not enabled, please use <WasmProfilers>browser;</WasmProfilers> in your project file.");
  if (options == null)
  options = {};
- const arg = "browser:";
+ let arg = "browser:";
+ if (typeof options.callSpec === "string") {
+ arg += `callspec=${options.callSpec},`;
+ }
+ if (typeof options.sampleIntervalMs === "number") {
+ arg += `interval=${options.sampleIntervalMs},`;
+ }
  cwraps.mono_wasm_profiler_init_browser(arg);
 }
 
@@ -76,6 +83,7 @@ export function startMeasure (): TimeStamp {
 
 export function endMeasure (start: TimeStamp, block: string, id?: string) {
  if (runtimeHelpers.enablePerfMeasure && start) {
+ // API is slightly different between web and Nodejs
  const options = ENVIRONMENT_IS_WEB
  ? { start: start as any }
  : { startTime: start as any };
@@ -84,28 +92,27 @@ export function endMeasure (start: TimeStamp, block: string, id?: string) {
  }
 }
 
-const stackFrames: number[] = [];
-export function mono_wasm_profiler_enter (): void {
- if (runtimeHelpers.enablePerfMeasure) {
- stackFrames.push(globalThis.performance.now());
- }
+export function mono_wasm_profiler_now (): number {
+ return globalThis.performance.now();
+}
+
+export function mono_wasm_profiler_free_method (method: MonoMethod): void {
+ methodNames.delete(method as any);
 }
 
 const methodNames: Map<number, string> = new Map();
-export function mono_wasm_profiler_leave (method: MonoMethod): void {
- if (runtimeHelpers.enablePerfMeasure) {
- const start = stackFrames.pop();
- const options = ENVIRONMENT_IS_WEB
- ? { start: start }
- : { startTime: start };
- let methodName = methodNames.get(method as any);
- if (!methodName) {
- const chars = cwraps.mono_wasm_method_get_name(method);
- methodName = utf8ToString(chars);
- methodNames.set(method as any, methodName);
- }
- globalThis.performance.measure(methodName, options);
+export function mono_wasm_profiler_record (method: MonoMethod, start: number): void {
+ const options = ENVIRONMENT_IS_WEB
+ ? { start: start }
+ : { startTime: start };
+ let methodName = methodNames.get(method as any);
+ if (!methodName) {
+ const chars = cwraps.mono_wasm_method_get_name_ex(method);
+ methodName = utf8ToString(chars);
+ methodNames.set(method as any, methodName);
+ free(chars as any);
  }
+ globalThis.performance.measure(methodName, options);
 }
 
 /* eslint-disable @typescript-eslint/no-unused-vars */

src/mono/browser/runtime/types/internal.ts

@@ -259,6 +259,12 @@ export type AOTProfilerOptions = {
 }
 
 export type BrowserProfilerOptions = {
+ sampleIntervalMs?: number, // default: 1000
+ /**
+ * See callspec in https://github.com/dotnet/runtime/blob/main/docs/design/mono/diagnostics-tracing.md#trace-monovm-profiler-events-during-startup
+ * When used together with Mono AOT, the callspec needs to match one in <WasmProfilers>browser:callspec=N:Sample;</WasmProfilers> in your project file.
+ */
+ callSpec?: string,
 }
 
 export type LogProfilerOptions = {

src/mono/mono/metadata/jit-icall-reg.h

@@ -250,6 +250,7 @@ MONO_JIT_ICALL (mono_ppc_throw_exception)	\
 MONO_JIT_ICALL (mono_profiler_raise_exception_clause) \
 MONO_JIT_ICALL (mono_profiler_raise_gc_allocation) \
 MONO_JIT_ICALL (mono_profiler_raise_method_enter) \
+MONO_JIT_ICALL (mono_profiler_raise_method_samplepoint) \
 MONO_JIT_ICALL (mono_profiler_raise_method_leave) \
 MONO_JIT_ICALL (mono_profiler_raise_method_tail_call) \
 MONO_JIT_ICALL (mono_resolve_generic_virtual_call) \
@@ -298,6 +299,7 @@ MONO_JIT_ICALL (mono_throw_platform_not_supported) \
 MONO_JIT_ICALL (mono_throw_invalid_program) \
 MONO_JIT_ICALL (mono_throw_type_load) \
 MONO_JIT_ICALL (mono_trace_enter_method) \
+MONO_JIT_ICALL (mono_trace_samplepoint_method) \
 MONO_JIT_ICALL (mono_trace_leave_method) \
 MONO_JIT_ICALL (mono_trace_tail_method) \
 MONO_JIT_ICALL (mono_upgrade_remote_class_wrapper) \

src/mono/browser/runtime/cwraps.ts

@@ -63,7 +63,6 @@ const fn_signatures: SigLine[] = [
  [() => !runtimeHelpers.emscriptenBuildOptions.enableAotProfiler, "mono_wasm_profiler_init_aot", "void", ["string"]],
  [() => !runtimeHelpers.emscriptenBuildOptions.enableBrowserProfiler, "mono_wasm_profiler_init_browser", "void", ["string"]],
  [() => !runtimeHelpers.emscriptenBuildOptions.enableLogProfiler, "mono_wasm_profiler_init_log", "void", ["string"]],
- [true, "mono_wasm_profiler_init_browser", "void", ["number"]],
  [false, "mono_wasm_exec_regression", "number", ["number", "string"]],
  [false, "mono_wasm_invoke_jsexport", "void", ["number", "number"]],
  [true, "mono_wasm_write_managed_pointer_unsafe", "void", ["number", "number"]],
@@ -73,6 +72,7 @@ const fn_signatures: SigLine[] = [
  [true, "mono_wasm_f64_to_i52", "number", ["number", "number"]],
  [true, "mono_wasm_f64_to_u52", "number", ["number", "number"]],
  [true, "mono_wasm_method_get_name", "number", ["number"]],
+ [true, "mono_wasm_method_get_name_ex", "number", ["number"]],
  [true, "mono_wasm_method_get_full_name", "number", ["number"]],
  [true, "mono_wasm_gc_lock", "void", []],
  [true, "mono_wasm_gc_unlock", "void", []],
@@ -131,6 +131,9 @@ const fn_signatures: SigLine[] = [
  [true, "mono_jiterp_end_catch", "void", []],
  [true, "mono_interp_pgo_load_table", "number", ["number", "number"]],
  [true, "mono_interp_pgo_save_table", "number", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_enter", "void", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_samplepoint", "void", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_leave", "void", ["number", "number"]],
 
  ...threading_cwraps,
 ];
@@ -193,6 +196,7 @@ export interface t_Cwraps {
  mono_wasm_f64_to_i52(destination: VoidPtr, value: number): I52Error;
  mono_wasm_f64_to_u52(destination: VoidPtr, value: number): I52Error;
  mono_wasm_method_get_name(method: MonoMethod): CharPtr;
+ mono_wasm_method_get_name_ex(method: MonoMethod): CharPtr;
  mono_wasm_method_get_full_name(method: MonoMethod): CharPtr;
  mono_wasm_gc_lock(): void;
  mono_wasm_gc_unlock(): void;

src/mono/browser/runtime/driver.c

@@ -534,6 +534,22 @@ EMSCRIPTEN_KEEPALIVE const char * mono_wasm_method_get_name (MonoMethod *method)
 	return res;
 }
 
+EMSCRIPTEN_KEEPALIVE const char * mono_wasm_method_get_name_ex (MonoMethod *method) {
+	const char *res;
+	MONO_ENTER_GC_UNSAFE;
+	res = mono_method_get_name (method);
+	// starts with .ctor or .cctor
+	if (mono_method_get_flags (method, NULL) & 0x0800 /* METHOD_ATTRIBUTE_SPECIAL_NAME */ && strlen (res) < 7) {
+ char *res_ex = (char *) malloc (128);
+ snprintf (res_ex, 128,"%s.%s", mono_class_get_name (mono_method_get_class (method)), res);
+ res = res_ex;
+	} else {
+ res = strdup (res);
+	}
+	MONO_EXIT_GC_UNSAFE;
+	return res;
+}
+
 EMSCRIPTEN_KEEPALIVE float mono_wasm_get_f32_unaligned (const float *src) {
 	return *src;
 }

src/mono/browser/runtime/es6/dotnet.es6.lib.js

@@ -90,6 +90,7 @@ function injectDependencies() {
  `enablePerfTracing: ${FEATURE_PERFTRACING ? "true" : "false"}, ` +
  `enableAotProfiler: ${ENABLE_AOT_PROFILER ? "true" : "false"}, ` +
  `enableBrowserProfiler: ${ENABLE_BROWSER_PROFILER ? "true" : "false"}, ` +
+ `enablePerfTracing: ${ENABLE_BROWSER_PROFILER ? "true" : "false"}, ` +
  `enableLogProfiler: ${ENABLE_LOG_PROFILER ? "true" : "false"}, ` +
  `runAOTCompilation: ${RUN_AOT_COMPILATION ? "true" : "false"}, ` +
  `wasmEnableThreads: ${USE_PTHREADS ? "true" : "false"}, ` +

src/mono/browser/runtime/exports-binding.ts

@@ -6,14 +6,14 @@ import WasmEnableThreads from "consts:wasmEnableThreads";
 import { mono_wasm_debugger_log, mono_wasm_add_dbg_command_received, mono_wasm_set_entrypoint_breakpoint, mono_wasm_fire_debugger_agent_message_with_data, mono_wasm_fire_debugger_agent_message_with_data_to_pause } from "./debug";
 import { mono_wasm_release_cs_owned_object } from "./gc-handles";
 import { mono_wasm_bind_js_import_ST, mono_wasm_invoke_js_function, mono_wasm_invoke_jsimport_MT, mono_wasm_invoke_jsimport_ST } from "./invoke-js";
-import { mono_interp_tier_prepare_jiterpreter, mono_jiterp_free_method_data_js } from "./jiterpreter";
+import { mono_interp_tier_prepare_jiterpreter, mono_wasm_free_method_data } from "./jiterpreter";
 import { mono_interp_jit_wasm_entry_trampoline, mono_interp_record_interp_entry } from "./jiterpreter-interp-entry";
 import { mono_interp_jit_wasm_jit_call_trampoline, mono_interp_invoke_wasm_jit_call_trampoline, mono_interp_flush_jitcall_queue } from "./jiterpreter-jit-call";
 import { mono_wasm_resolve_or_reject_promise } from "./marshal-to-js";
 import { mono_wasm_schedule_timer, schedule_background_exec } from "./scheduling";
 import { mono_wasm_asm_loaded } from "./startup";
 import { mono_log_warn, mono_wasm_console_clear, mono_wasm_trace_logger } from "./logging";
-import { mono_wasm_profiler_leave, mono_wasm_profiler_enter, ds_rt_websocket_close, ds_rt_websocket_create, ds_rt_websocket_poll, ds_rt_websocket_recv, ds_rt_websocket_send } from "./profiler";
+import { mono_wasm_profiler_record, mono_wasm_profiler_now, ds_rt_websocket_close, ds_rt_websocket_create, ds_rt_websocket_poll, ds_rt_websocket_recv, ds_rt_websocket_send } from "./profiler";
 import { mono_wasm_browser_entropy } from "./crypto";
 import { mono_wasm_cancel_promise } from "./cancelable-promise";
 
@@ -68,10 +68,10 @@ export const mono_wasm_imports = [
  mono_interp_jit_wasm_jit_call_trampoline,
  mono_interp_invoke_wasm_jit_call_trampoline,
  mono_interp_flush_jitcall_queue,
-mono_jiterp_free_method_data_js,
+mono_wasm_free_method_data,
 
-mono_wasm_profiler_enter,
-mono_wasm_profiler_leave,
+mono_wasm_profiler_now,
+mono_wasm_profiler_record,
 
  // driver.c
  mono_wasm_trace_logger,

src/mono/browser/runtime/jiterpreter-support.ts

@@ -1600,6 +1600,27 @@ export const _now = (globalThis.performance && globalThis.performance.now)
 
 let scratchBuffer: NativePointer = <any>0;
 
+export function append_profiler_event (builder: WasmBuilder, ip: MintOpcodePtr, opcode: MintOpcode) {
+ let event_name:string;
+ switch (opcode) {
+ case MintOpcode.MINT_PROF_ENTER:
+ event_name = "prof_enter";
+ break;
+ case MintOpcode.MINT_PROF_SAMPLEPOINT:
+ event_name = "prof_samplepoint";
+ break;
+ case MintOpcode.MINT_PROF_EXIT:
+ case MintOpcode.MINT_PROF_EXIT_VOID:
+ event_name = "prof_leave";
+ break;
+ default:
+ throw new Error(`Unimplemented profiler event ${opcode}`);
+ }
+ builder.local("frame");
+ builder.i32_const(ip);
+ builder.callImport(event_name);
+}
+
 export function append_safepoint (builder: WasmBuilder, ip: MintOpcodePtr) {
  // safepoints are never triggered in a single-threaded build
  if (!WasmEnableThreads)

src/mono/browser/runtime/jiterpreter-trace-generator.ts

@@ -28,6 +28,7 @@ import {
  try_append_memmove_fast, getOpcodeTableValue,
  getMemberOffset, isZeroPageReserved, CfgBranchType,
  append_safepoint, modifyCounter, simdFallbackCounters,
+ append_profiler_event,
 } from "./jiterpreter-support";
 import {
  sizeOfDataItem, sizeOfV128, sizeOfStackval,
@@ -1415,9 +1416,15 @@ export function generateWasmBody (
  }
 
  case MintOpcode.MINT_RETHROW:
+ ip = abort;
+ break;
+
+ // call C
+ case MintOpcode.MINT_PROF_ENTER:
+ case MintOpcode.MINT_PROF_SAMPLEPOINT:
  case MintOpcode.MINT_PROF_EXIT:
  case MintOpcode.MINT_PROF_EXIT_VOID:
-ip = abort;
+append_profiler_event(builder, ip, opcode);
  break;
 
  // Generating code for these is kind of complex due to the intersection of JS and int64,

src/mono/browser/runtime/jiterpreter.ts

@@ -26,6 +26,7 @@ import { mono_jiterp_free_method_data_interp_entry } from "./jiterpreter-interp-
 import { mono_jiterp_free_method_data_jit_call } from "./jiterpreter-jit-call";
 import { mono_log_error, mono_log_info, mono_log_warn } from "./logging";
 import { utf8ToString } from "./strings";
+import { mono_wasm_profiler_free_method } from "./profiler";
 
 // Controls miscellaneous diagnostic output.
 export const trace = 0;
@@ -298,6 +299,12 @@ function getTraceImports () {
  if (nullCheckValidation)
  traceImports.push(importDef("notnull", assert_not_null));
 
+ if (runtimeHelpers.emscriptenBuildOptions.enablePerfTracing) {
+ traceImports.push(importDef("prof_enter", getRawCwrap("mono_jiterp_prof_enter")));
+ traceImports.push(importDef("prof_samplepoint", getRawCwrap("mono_jiterp_prof_samplepoint")));
+ traceImports.push(importDef("prof_leave", getRawCwrap("mono_jiterp_prof_leave")));
+ }
+
  const pushMathOps = (list: string[], type: string) => {
  for (let i = 0; i < list.length; i++) {
  const mop = list[i];
@@ -579,6 +586,30 @@ function initialize_builder (builder: WasmBuilder) {
  },
  WasmValtype.void, true
  );
+ builder.defineType(
+ "prof_enter",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
+ builder.defineType(
+ "prof_samplepoint",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
+ builder.defineType(
+ "prof_leave",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
  builder.defineType(
  "hashcode",
  {
@@ -1050,9 +1081,13 @@ export function mono_interp_tier_prepare_jiterpreter (
 
 // NOTE: This will potentially be called once for every trace entry point
 // in a given method, not just once per method
-export function mono_jiterp_free_method_data_js (
+export function mono_wasm_free_method_data (
  method: MonoMethod, imethod: number, traceIndex: number
 ) {
+ if (runtimeHelpers.emscriptenBuildOptions.enablePerfTracing) {
+ mono_wasm_profiler_free_method(method);
+ }
+
  // TODO: Uninstall the trace function pointer from the function pointer table,
  // so that the compiled trace module can be freed by the browser eventually
  // Release the trace info object, if present

src/mono/browser/runtime/profiler.ts

@@ -7,6 +7,7 @@ import { ENVIRONMENT_IS_WEB, mono_assert, runtimeHelpers } from "./globals";
 import { MonoMethod, AOTProfilerOptions, BrowserProfilerOptions, LogProfilerOptions } from "./types/internal";
 import { profiler_c_functions as cwraps } from "./cwraps";
 import { utf8ToString } from "./strings";
+import { free } from "./memory";
 
 // Initialize the AOT profiler with OPTIONS.
 // Requires the AOT profiler to be linked into the app.
@@ -32,7 +33,13 @@ export function mono_wasm_init_browser_profiler (options: BrowserProfilerOptions
  mono_assert(runtimeHelpers.emscriptenBuildOptions.enableBrowserProfiler, "Browser profiler is not enabled, please use <WasmProfilers>browser;</WasmProfilers> in your project file.");
  if (options == null)
  options = {};
- const arg = "browser:";
+ let arg = "browser:";
+ if (typeof options.callSpec === "string") {
+ arg += `callspec=${options.callSpec},`;
+ }
+ if (typeof options.sampleIntervalMs === "number") {
+ arg += `interval=${options.sampleIntervalMs},`;
+ }
  cwraps.mono_wasm_profiler_init_browser(arg);
 }
 
@@ -76,6 +83,7 @@ export function startMeasure (): TimeStamp {
 
 export function endMeasure (start: TimeStamp, block: string, id?: string) {
  if (runtimeHelpers.enablePerfMeasure && start) {
+ // API is slightly different between web and Nodejs
  const options = ENVIRONMENT_IS_WEB
  ? { start: start as any }
  : { startTime: start as any };
@@ -84,28 +92,27 @@ export function endMeasure (start: TimeStamp, block: string, id?: string) {
  }
 }
 
-const stackFrames: number[] = [];
-export function mono_wasm_profiler_enter (): void {
- if (runtimeHelpers.enablePerfMeasure) {
- stackFrames.push(globalThis.performance.now());
- }
+export function mono_wasm_profiler_now (): number {
+ return globalThis.performance.now();
+}
+
+export function mono_wasm_profiler_free_method (method: MonoMethod): void {
+ methodNames.delete(method as any);
 }
 
 const methodNames: Map<number, string> = new Map();
-export function mono_wasm_profiler_leave (method: MonoMethod): void {
- if (runtimeHelpers.enablePerfMeasure) {
- const start = stackFrames.pop();
- const options = ENVIRONMENT_IS_WEB
- ? { start: start }
- : { startTime: start };
- let methodName = methodNames.get(method as any);
- if (!methodName) {
- const chars = cwraps.mono_wasm_method_get_name(method);
- methodName = utf8ToString(chars);
- methodNames.set(method as any, methodName);
- }
- globalThis.performance.measure(methodName, options);
+export function mono_wasm_profiler_record (method: MonoMethod, start: number): void {
+ const options = ENVIRONMENT_IS_WEB
+ ? { start: start }
+ : { startTime: start };
+ let methodName = methodNames.get(method as any);
+ if (!methodName) {
+ const chars = cwraps.mono_wasm_method_get_name_ex(method);
+ methodName = utf8ToString(chars);
+ methodNames.set(method as any, methodName);
+ free(chars as any);
  }
+ globalThis.performance.measure(methodName, options);
 }
 
 /* eslint-disable @typescript-eslint/no-unused-vars */

src/mono/browser/runtime/types/internal.ts

@@ -259,6 +259,12 @@ export type AOTProfilerOptions = {
 }
 
 export type BrowserProfilerOptions = {
+ sampleIntervalMs?: number, // default: 1000
+ /**
+ * See callspec in https://github.com/dotnet/runtime/blob/main/docs/design/mono/diagnostics-tracing.md#trace-monovm-profiler-events-during-startup
+ * When used together with Mono AOT, the callspec needs to match one in <WasmProfilers>browser:callspec=N:Sample;</WasmProfilers> in your project file.
+ */
+ callSpec?: string,
 }
 
 export type LogProfilerOptions = {

src/mono/mono/metadata/jit-icall-reg.h

@@ -250,6 +250,7 @@ MONO_JIT_ICALL (mono_ppc_throw_exception)	\
 MONO_JIT_ICALL (mono_profiler_raise_exception_clause) \
 MONO_JIT_ICALL (mono_profiler_raise_gc_allocation) \
 MONO_JIT_ICALL (mono_profiler_raise_method_enter) \
+MONO_JIT_ICALL (mono_profiler_raise_method_samplepoint) \
 MONO_JIT_ICALL (mono_profiler_raise_method_leave) \
 MONO_JIT_ICALL (mono_profiler_raise_method_tail_call) \
 MONO_JIT_ICALL (mono_resolve_generic_virtual_call) \
@@ -298,6 +299,7 @@ MONO_JIT_ICALL (mono_throw_platform_not_supported) \
 MONO_JIT_ICALL (mono_throw_invalid_program) \
 MONO_JIT_ICALL (mono_throw_type_load) \
 MONO_JIT_ICALL (mono_trace_enter_method) \
+MONO_JIT_ICALL (mono_trace_samplepoint_method) \
 MONO_JIT_ICALL (mono_trace_leave_method) \
 MONO_JIT_ICALL (mono_trace_tail_method) \
 MONO_JIT_ICALL (mono_upgrade_remote_class_wrapper) \

src/mono/browser/runtime/cwraps.ts

@@ -63,7 +63,6 @@ const fn_signatures: SigLine[] = [
  [() => !runtimeHelpers.emscriptenBuildOptions.enableAotProfiler, "mono_wasm_profiler_init_aot", "void", ["string"]],
  [() => !runtimeHelpers.emscriptenBuildOptions.enableBrowserProfiler, "mono_wasm_profiler_init_browser", "void", ["string"]],
  [() => !runtimeHelpers.emscriptenBuildOptions.enableLogProfiler, "mono_wasm_profiler_init_log", "void", ["string"]],
- [true, "mono_wasm_profiler_init_browser", "void", ["number"]],
  [false, "mono_wasm_exec_regression", "number", ["number", "string"]],
  [false, "mono_wasm_invoke_jsexport", "void", ["number", "number"]],
  [true, "mono_wasm_write_managed_pointer_unsafe", "void", ["number", "number"]],
@@ -73,6 +72,7 @@ const fn_signatures: SigLine[] = [
  [true, "mono_wasm_f64_to_i52", "number", ["number", "number"]],
  [true, "mono_wasm_f64_to_u52", "number", ["number", "number"]],
  [true, "mono_wasm_method_get_name", "number", ["number"]],
+ [true, "mono_wasm_method_get_name_ex", "number", ["number"]],
  [true, "mono_wasm_method_get_full_name", "number", ["number"]],
  [true, "mono_wasm_gc_lock", "void", []],
  [true, "mono_wasm_gc_unlock", "void", []],
@@ -131,6 +131,9 @@ const fn_signatures: SigLine[] = [
  [true, "mono_jiterp_end_catch", "void", []],
  [true, "mono_interp_pgo_load_table", "number", ["number", "number"]],
  [true, "mono_interp_pgo_save_table", "number", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_enter", "void", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_samplepoint", "void", ["number", "number"]],
+ [() => !runtimeHelpers.emscriptenBuildOptions.enablePerfTracing, "mono_jiterp_prof_leave", "void", ["number", "number"]],
 
  ...threading_cwraps,
 ];
@@ -193,6 +196,7 @@ export interface t_Cwraps {
  mono_wasm_f64_to_i52(destination: VoidPtr, value: number): I52Error;
  mono_wasm_f64_to_u52(destination: VoidPtr, value: number): I52Error;
  mono_wasm_method_get_name(method: MonoMethod): CharPtr;
+ mono_wasm_method_get_name_ex(method: MonoMethod): CharPtr;
  mono_wasm_method_get_full_name(method: MonoMethod): CharPtr;
  mono_wasm_gc_lock(): void;
  mono_wasm_gc_unlock(): void;

src/mono/browser/runtime/driver.c

@@ -534,6 +534,22 @@ EMSCRIPTEN_KEEPALIVE const char * mono_wasm_method_get_name (MonoMethod *method)
 	return res;
 }
 
+EMSCRIPTEN_KEEPALIVE const char * mono_wasm_method_get_name_ex (MonoMethod *method) {
+	const char *res;
+	MONO_ENTER_GC_UNSAFE;
+	res = mono_method_get_name (method);
+	// starts with .ctor or .cctor
+	if (mono_method_get_flags (method, NULL) & 0x0800 /* METHOD_ATTRIBUTE_SPECIAL_NAME */ && strlen (res) < 7) {
+ char *res_ex = (char *) malloc (128);
+ snprintf (res_ex, 128,"%s.%s", mono_class_get_name (mono_method_get_class (method)), res);
+ res = res_ex;
+	} else {
+ res = strdup (res);
+	}
+	MONO_EXIT_GC_UNSAFE;
+	return res;
+}
+
 EMSCRIPTEN_KEEPALIVE float mono_wasm_get_f32_unaligned (const float *src) {
 	return *src;
 }

src/mono/browser/runtime/es6/dotnet.es6.lib.js

@@ -90,6 +90,7 @@ function injectDependencies() {
  `enablePerfTracing: ${FEATURE_PERFTRACING ? "true" : "false"}, ` +
  `enableAotProfiler: ${ENABLE_AOT_PROFILER ? "true" : "false"}, ` +
  `enableBrowserProfiler: ${ENABLE_BROWSER_PROFILER ? "true" : "false"}, ` +
+ `enablePerfTracing: ${ENABLE_BROWSER_PROFILER ? "true" : "false"}, ` +
  `enableLogProfiler: ${ENABLE_LOG_PROFILER ? "true" : "false"}, ` +
  `runAOTCompilation: ${RUN_AOT_COMPILATION ? "true" : "false"}, ` +
  `wasmEnableThreads: ${USE_PTHREADS ? "true" : "false"}, ` +

src/mono/browser/runtime/exports-binding.ts

@@ -6,14 +6,14 @@ import WasmEnableThreads from "consts:wasmEnableThreads";
 import { mono_wasm_debugger_log, mono_wasm_add_dbg_command_received, mono_wasm_set_entrypoint_breakpoint, mono_wasm_fire_debugger_agent_message_with_data, mono_wasm_fire_debugger_agent_message_with_data_to_pause } from "./debug";
 import { mono_wasm_release_cs_owned_object } from "./gc-handles";
 import { mono_wasm_bind_js_import_ST, mono_wasm_invoke_js_function, mono_wasm_invoke_jsimport_MT, mono_wasm_invoke_jsimport_ST } from "./invoke-js";
-import { mono_interp_tier_prepare_jiterpreter, mono_jiterp_free_method_data_js } from "./jiterpreter";
+import { mono_interp_tier_prepare_jiterpreter, mono_wasm_free_method_data } from "./jiterpreter";
 import { mono_interp_jit_wasm_entry_trampoline, mono_interp_record_interp_entry } from "./jiterpreter-interp-entry";
 import { mono_interp_jit_wasm_jit_call_trampoline, mono_interp_invoke_wasm_jit_call_trampoline, mono_interp_flush_jitcall_queue } from "./jiterpreter-jit-call";
 import { mono_wasm_resolve_or_reject_promise } from "./marshal-to-js";
 import { mono_wasm_schedule_timer, schedule_background_exec } from "./scheduling";
 import { mono_wasm_asm_loaded } from "./startup";
 import { mono_log_warn, mono_wasm_console_clear, mono_wasm_trace_logger } from "./logging";
-import { mono_wasm_profiler_leave, mono_wasm_profiler_enter, ds_rt_websocket_close, ds_rt_websocket_create, ds_rt_websocket_poll, ds_rt_websocket_recv, ds_rt_websocket_send } from "./profiler";
+import { mono_wasm_profiler_record, mono_wasm_profiler_now, ds_rt_websocket_close, ds_rt_websocket_create, ds_rt_websocket_poll, ds_rt_websocket_recv, ds_rt_websocket_send } from "./profiler";
 import { mono_wasm_browser_entropy } from "./crypto";
 import { mono_wasm_cancel_promise } from "./cancelable-promise";
 
@@ -68,10 +68,10 @@ export const mono_wasm_imports = [
  mono_interp_jit_wasm_jit_call_trampoline,
  mono_interp_invoke_wasm_jit_call_trampoline,
  mono_interp_flush_jitcall_queue,
-mono_jiterp_free_method_data_js,
+mono_wasm_free_method_data,
 
-mono_wasm_profiler_enter,
-mono_wasm_profiler_leave,
+mono_wasm_profiler_now,
+mono_wasm_profiler_record,
 
  // driver.c
  mono_wasm_trace_logger,

src/mono/browser/runtime/jiterpreter-support.ts

@@ -1600,6 +1600,27 @@ export const _now = (globalThis.performance && globalThis.performance.now)
 
 let scratchBuffer: NativePointer = <any>0;
 
+export function append_profiler_event (builder: WasmBuilder, ip: MintOpcodePtr, opcode: MintOpcode) {
+ let event_name:string;
+ switch (opcode) {
+ case MintOpcode.MINT_PROF_ENTER:
+ event_name = "prof_enter";
+ break;
+ case MintOpcode.MINT_PROF_SAMPLEPOINT:
+ event_name = "prof_samplepoint";
+ break;
+ case MintOpcode.MINT_PROF_EXIT:
+ case MintOpcode.MINT_PROF_EXIT_VOID:
+ event_name = "prof_leave";
+ break;
+ default:
+ throw new Error(`Unimplemented profiler event ${opcode}`);
+ }
+ builder.local("frame");
+ builder.i32_const(ip);
+ builder.callImport(event_name);
+}
+
 export function append_safepoint (builder: WasmBuilder, ip: MintOpcodePtr) {
  // safepoints are never triggered in a single-threaded build
  if (!WasmEnableThreads)

src/mono/browser/runtime/jiterpreter-trace-generator.ts

@@ -28,6 +28,7 @@ import {
  try_append_memmove_fast, getOpcodeTableValue,
  getMemberOffset, isZeroPageReserved, CfgBranchType,
  append_safepoint, modifyCounter, simdFallbackCounters,
+ append_profiler_event,
 } from "./jiterpreter-support";
 import {
  sizeOfDataItem, sizeOfV128, sizeOfStackval,
@@ -1415,9 +1416,15 @@ export function generateWasmBody (
  }
 
  case MintOpcode.MINT_RETHROW:
+ ip = abort;
+ break;
+
+ // call C
+ case MintOpcode.MINT_PROF_ENTER:
+ case MintOpcode.MINT_PROF_SAMPLEPOINT:
  case MintOpcode.MINT_PROF_EXIT:
  case MintOpcode.MINT_PROF_EXIT_VOID:
-ip = abort;
+append_profiler_event(builder, ip, opcode);
  break;
 
  // Generating code for these is kind of complex due to the intersection of JS and int64,

src/mono/browser/runtime/jiterpreter.ts

@@ -26,6 +26,7 @@ import { mono_jiterp_free_method_data_interp_entry } from "./jiterpreter-interp-
 import { mono_jiterp_free_method_data_jit_call } from "./jiterpreter-jit-call";
 import { mono_log_error, mono_log_info, mono_log_warn } from "./logging";
 import { utf8ToString } from "./strings";
+import { mono_wasm_profiler_free_method } from "./profiler";
 
 // Controls miscellaneous diagnostic output.
 export const trace = 0;
@@ -298,6 +299,12 @@ function getTraceImports () {
  if (nullCheckValidation)
  traceImports.push(importDef("notnull", assert_not_null));
 
+ if (runtimeHelpers.emscriptenBuildOptions.enablePerfTracing) {
+ traceImports.push(importDef("prof_enter", getRawCwrap("mono_jiterp_prof_enter")));
+ traceImports.push(importDef("prof_samplepoint", getRawCwrap("mono_jiterp_prof_samplepoint")));
+ traceImports.push(importDef("prof_leave", getRawCwrap("mono_jiterp_prof_leave")));
+ }
+
  const pushMathOps = (list: string[], type: string) => {
  for (let i = 0; i < list.length; i++) {
  const mop = list[i];
@@ -579,6 +586,30 @@ function initialize_builder (builder: WasmBuilder) {
  },
  WasmValtype.void, true
  );
+ builder.defineType(
+ "prof_enter",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
+ builder.defineType(
+ "prof_samplepoint",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
+ builder.defineType(
+ "prof_leave",
+ {
+ "frame": WasmValtype.i32,
+ "ip": WasmValtype.i32,
+ },
+ WasmValtype.void, true
+ );
  builder.defineType(
  "hashcode",
  {
@@ -1050,9 +1081,13 @@ export function mono_interp_tier_prepare_jiterpreter (
 
 // NOTE: This will potentially be called once for every trace entry point
 // in a given method, not just once per method
-export function mono_jiterp_free_method_data_js (
+export function mono_wasm_free_method_data (
  method: MonoMethod, imethod: number, traceIndex: number
 ) {
+ if (runtimeHelpers.emscriptenBuildOptions.enablePerfTracing) {
+ mono_wasm_profiler_free_method(method);
+ }
+
  // TODO: Uninstall the trace function pointer from the function pointer table,
  // so that the compiled trace module can be freed by the browser eventually
  // Release the trace info object, if present

src/mono/browser/runtime/profiler.ts

@@ -7,6 +7,7 @@ import { ENVIRONMENT_IS_WEB, mono_assert, runtimeHelpers } from "./globals";
 import { MonoMethod, AOTProfilerOptions, BrowserProfilerOptions, LogProfilerOptions } from "./types/internal";
 import { profiler_c_functions as cwraps } from "./cwraps";
 import { utf8ToString } from "./strings";
+import { free } from "./memory";
 
 // Initialize the AOT profiler with OPTIONS.
 // Requires the AOT profiler to be linked into the app.
@@ -32,7 +33,13 @@ export function mono_wasm_init_browser_profiler (options: BrowserProfilerOptions
  mono_assert(runtimeHelpers.emscriptenBuildOptions.enableBrowserProfiler, "Browser profiler is not enabled, please use <WasmProfilers>browser;</WasmProfilers> in your project file.");
  if (options == null)
  options = {};
- const arg = "browser:";
+ let arg = "browser:";
+ if (typeof options.callSpec === "string") {
+ arg += `callspec=${options.callSpec},`;
+ }
+ if (typeof options.sampleIntervalMs === "number") {
+ arg += `interval=${options.sampleIntervalMs},`;
+ }
  cwraps.mono_wasm_profiler_init_browser(arg);
 }
 
@@ -76,6 +83,7 @@ export function startMeasure (): TimeStamp {
 
 export function endMeasure (start: TimeStamp, block: string, id?: string) {
  if (runtimeHelpers.enablePerfMeasure && start) {
+ // API is slightly different between web and Nodejs
  const options = ENVIRONMENT_IS_WEB
  ? { start: start as any }
  : { startTime: start as any };
@@ -84,28 +92,27 @@ export function endMeasure (start: TimeStamp, block: string, id?: string) {
  }
 }
 
-const stackFrames: number[] = [];
-export function mono_wasm_profiler_enter (): void {
- if (runtimeHelpers.enablePerfMeasure) {
- stackFrames.push(globalThis.performance.now());
- }
+export function mono_wasm_profiler_now (): number {
+ return globalThis.performance.now();
+}
+
+export function mono_wasm_profiler_free_method (method: MonoMethod): void {
+ methodNames.delete(method as any);
 }
 
 const methodNames: Map<number, string> = new Map();
-export function mono_wasm_profiler_leave (method: MonoMethod): void {
- if (runtimeHelpers.enablePerfMeasure) {
- const start = stackFrames.pop();
- const options = ENVIRONMENT_IS_WEB
- ? { start: start }
- : { startTime: start };
- let methodName = methodNames.get(method as any);
- if (!methodName) {
- const chars = cwraps.mono_wasm_method_get_name(method);
- methodName = utf8ToString(chars);
- methodNames.set(method as any, methodName);
- }
- globalThis.performance.measure(methodName, options);
+export function mono_wasm_profiler_record (method: MonoMethod, start: number): void {
+ const options = ENVIRONMENT_IS_WEB
+ ? { start: start }
+ : { startTime: start };
+ let methodName = methodNames.get(method as any);
+ if (!methodName) {
+ const chars = cwraps.mono_wasm_method_get_name_ex(method);
+ methodName = utf8ToString(chars);
+ methodNames.set(method as any, methodName);
+ free(chars as any);
  }
+ globalThis.performance.measure(methodName, options);
 }
 
 /* eslint-disable @typescript-eslint/no-unused-vars */

src/mono/browser/runtime/types/internal.ts

@@ -259,6 +259,12 @@ export type AOTProfilerOptions = {
 }
 
 export type BrowserProfilerOptions = {
+ sampleIntervalMs?: number, // default: 1000
+ /**
+ * See callspec in https://github.com/dotnet/runtime/blob/main/docs/design/mono/diagnostics-tracing.md#trace-monovm-profiler-events-during-startup
+ * When used together with Mono AOT, the callspec needs to match one in <WasmProfilers>browser:callspec=N:Sample;</WasmProfilers> in your project file.
+ */
+ callSpec?: string,
 }
 
 export type LogProfilerOptions = {

src/mono/mono/metadata/jit-icall-reg.h

@@ -250,6 +250,7 @@ MONO_JIT_ICALL (mono_ppc_throw_exception)	\
 MONO_JIT_ICALL (mono_profiler_raise_exception_clause) \
 MONO_JIT_ICALL (mono_profiler_raise_gc_allocation) \
 MONO_JIT_ICALL (mono_profiler_raise_method_enter) \
+MONO_JIT_ICALL (mono_profiler_raise_method_samplepoint) \
 MONO_JIT_ICALL (mono_profiler_raise_method_leave) \
 MONO_JIT_ICALL (mono_profiler_raise_method_tail_call) \
 MONO_JIT_ICALL (mono_resolve_generic_virtual_call) \
@@ -298,6 +299,7 @@ MONO_JIT_ICALL (mono_throw_platform_not_supported) \
 MONO_JIT_ICALL (mono_throw_invalid_program) \
 MONO_JIT_ICALL (mono_throw_type_load) \
 MONO_JIT_ICALL (mono_trace_enter_method) \
+MONO_JIT_ICALL (mono_trace_samplepoint_method) \
 MONO_JIT_ICALL (mono_trace_leave_method) \
 MONO_JIT_ICALL (mono_trace_tail_method) \
 MONO_JIT_ICALL (mono_upgrade_remote_class_wrapper) \