Harden async-profiler dispatcher/wrapper frame name contract for callstack stitching. - #131963

Merged
lateralusX merged 1 commit into
dotnet:mainfrom
lateralusX:lateralusX/async-profiler-contract-validation
Aug 7, 2026
Merged

Harden async-profiler dispatcher/wrapper frame name contract for callstack stitching.#131963
lateralusX merged 1 commit into
dotnet:mainfrom
lateralusX:lateralusX/async-profiler-contract-validation

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Changes

Runtime (System.Private.CoreLib)

  • Add [StackTraceHidden] to the V1 dispatch frames (InstrumentedMoveNext, MoveNextAsDispatcher, AsyncStateMachineDispatcher.MoveNext) so V1 matches the already-hidden V2 dispatch frames. These frames stay out of managed stack traces but remain in the physical stack and in stack-trace metadata.
  • Add name-contract comments (placed uniformly below the attribute) on the methods and types diagnostic tooling depends on by name.
  • Rename the (not-yet-shipped) env var DOTNET_AsyncProfilerEventSource_EventBufferSize → DOTNET_AsyncProfiler_EventBufferSize; remove an unused using.

Tests (System.Threading.Tasks.Tests)

  • Name-contract tests pin the identifiers the stitcher hardcodes: V1/V2 dispatch methods, and the V2 continuation wrappers (all 32 exist, none beyond — hardcoded rather than reflected so drift can't pass silently).
  • Frame-capture tests capture the unfiltered physical managed stack from inside a resumed continuation and assert the boundary frames appear in the expected leaf→root order:
    • RuntimeAsync_ResumeDispatchStack (V2 single-yield)
    • StateMachineAsync_ResumeDispatchStack (V1 single-yield)
    • StateMachineAsync_PoolingResumeDispatchStack (V1 pooling → standalone
      AsyncStateMachineDispatcher)
    • StateMachineAsync_InlineCompletionClimb (V1 inline completion, child frames remain beneath the resuming parent)
  • Frame identity is resolved via DiagnosticMethodInfo (stack-trace metadata) rather than StackFrame.GetMethod() (reflection), so the tests work on CoreCLR, Mono, and NativeAOT — the latter trims reflection metadata but preserves stack-trace metadata (including names for [StackTraceHidden] Ecma methods).

Tests are gated by runtime capability: V1 tests run on CoreCLR + Mono; V2 tests run on CoreCLR (+ NativeAOT for the frame-capture test); reflection-based name-contract tests are CoreCLR/Mono only.

Risk / compatibility

  • No change to async dispatch behavior. [StackTraceHidden] only affects stack-trace display, and the newly-hidden V1 InstrumentedMoveNext frames are only present when the async profiler is active.
  • The env-var rename targets an unshipped diagnostic knob, so it is not a breaking change.

@lateralusX
External CPU-callstack stitchers identifies async dispatch and
c16e121
continuation-wrapper frames by method/type name and expects them
to be consistently filtered from managed stack traces. Nothing
in the runtime guarded that implicit contract, so a rename,
an added/removed continuation wrapper, or a lost [StackTraceHidden]
marker could silently break async callstack stitching for both
StateMachineAsync (V1) and RuntimeAsync (V2).
Runtime (System.Private.CoreLib):
- Mark the V1 state-machine dispatch frames [StackTraceHidden]
(InstrumentedMoveNext, MoveNextAsDispatcher, AsyncStateMachineDispatcher.MoveNext)
to match the V2 RuntimeAsync dispatch frames, so they are consistently hidden
from managed stack traces while remaining resolvable by name from stack-trace
metadata.
- Add diagnostic-tooling name-contract comments (unified below the attribute) on
the dispatcher/wrapper methods the stitcher recognizes by name.
- Rename the (unshipped) env var DOTNET_AsyncProfilerEventSource_EventBufferSize
to DOTNET_AsyncProfiler_EventBufferSize for naming consistency; drop a now-unused
using.
Tests (System.Threading.Tasks.Tests):
- Name-contract tests pinning the exact names/count the stitcher hardcodes: V1/V2
dispatch methods and the 32 V2 continuation-wrapper methods (asserting all 32
exist and none beyond).
- Frame-capture tests that capture the UNFILTERED physical managed stack from
inside a resumed continuation and assert the boundary frames appear in the
expected leaf->root order: V2 single-yield, V1 single-yield, V1 pooling, and V1
inline-completion climb. Frame identity is resolved via DiagnosticMethodInfo so
the tests work on CoreCLR, Mono, and NativeAOT (where reflection metadata is
trimmed but stack-trace metadata is not).
CopilotAI review requested due to automatic review settings August 6, 2026 19:31
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@lateralusX

lateralusX commented Aug 7, 2026

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/ba-g known issue #131956

@lateralusX
lateralusX merged commit 45fb46d into dotnet:mainAug 7, 2026
146 of 148 checks passed
@dotnet-maestrodotnet-maestroBot mentioned this pull request Aug 7, 2026
Merged
@dotnet-milestone-botdotnet-milestone-botBot added this to the 11.0-rc1 milestone Aug 7, 2026
jtschuster pushed a commit to jtschuster/runtime that referenced this pull request Aug 11, 2026
@lateralusX@jtschuster
Harden async-profiler dispatcher/wrapper frame name contract for call…
b1c50e9
…stack stitching. (dotnet#131963)
## Changes
**Runtime (`System.Private.CoreLib`)**
- Add `[StackTraceHidden]` to the V1 dispatch frames
(`InstrumentedMoveNext`, `MoveNextAsDispatcher`,
`AsyncStateMachineDispatcher.MoveNext`) so V1 matches the already-hidden
V2 dispatch frames. These frames stay out of managed stack traces but
remain in the physical stack and in stack-trace metadata.
- Add name-contract comments (placed uniformly below the attribute) on
the methods and types diagnostic tooling depends on by name.
- Rename the (not-yet-shipped) env var
`DOTNET_AsyncProfilerEventSource_EventBufferSize` →
`DOTNET_AsyncProfiler_EventBufferSize`; remove an unused `using`.
**Tests (`System.Threading.Tasks.Tests`)**
- **Name-contract tests** pin the identifiers the stitcher hardcodes:
V1/V2 dispatch methods, and the V2 continuation wrappers (all 32 exist,
none beyond — hardcoded rather than reflected so drift can't pass
silently).
- **Frame-capture tests** capture the unfiltered physical managed stack
from inside a resumed continuation and assert the boundary frames appear
in the expected leaf→root order:
- `RuntimeAsync_ResumeDispatchStack` (V2 single-yield)
- `StateMachineAsync_ResumeDispatchStack` (V1 single-yield)
- `StateMachineAsync_PoolingResumeDispatchStack` (V1 pooling →
standalone
`AsyncStateMachineDispatcher`)
- `StateMachineAsync_InlineCompletionClimb` (V1 inline completion, child
frames remain beneath the resuming parent)
- Frame identity is resolved via `DiagnosticMethodInfo` (stack-trace
metadata) rather than `StackFrame.GetMethod()` (reflection), so the
tests work on CoreCLR, Mono, and NativeAOT — the latter trims reflection
metadata but preserves stack-trace metadata (including names for
`[StackTraceHidden]` Ecma methods).
Tests are gated by runtime capability: V1 tests run on CoreCLR + Mono;
V2 tests run on CoreCLR (+ NativeAOT for the frame-capture test);
reflection-based name-contract tests are CoreCLR/Mono only.
## Risk / compatibility
- No change to async dispatch behavior. `[StackTraceHidden]` only
affects stack-trace *display*, and the newly-hidden V1
`InstrumentedMoveNext` frames are only present when the async profiler
is active.
- The env-var rename targets an unshipped diagnostic knob, so it is not
a breaking change.
@steveisoksteveisok mentioned this pull request Aug 11, 2026
Closed
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, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

Skip to content
Harden async-profiler dispatcher/wrapper frame name contract for callstack stitching. - #131963
Merged
lateralusX merged 1 commit into
dotnet:mainfrom 
lateralusX:lateralusX/async-profiler-contract-validation
Aug 7, 2026
Merged
Harden async-profiler dispatcher/wrapper frame name contract for callstack stitching.#131963
lateralusX merged 1 commit into
dotnet:mainfrom 
lateralusX:lateralusX/async-profiler-contract-validation
Conversation
@lateralusX
@lateralusXlateralusX
commented
Aug 6, 2026

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Changes
Runtime (System.Private.CoreLib)
  • Add [StackTraceHidden] to the V1 dispatch frames (InstrumentedMoveNext, MoveNextAsDispatcher, AsyncStateMachineDispatcher.MoveNext) so V1 matches the already-hidden V2 dispatch frames. These frames stay out of managed stack traces but remain in the physical stack and in stack-trace metadata.
  • Add name-contract comments (placed uniformly below the attribute) on the methods and types diagnostic tooling depends on by name.
  • Rename the (not-yet-shipped) env var DOTNET_AsyncProfilerEventSource_EventBufferSize → DOTNET_AsyncProfiler_EventBufferSize; remove an unused using.
Tests (System.Threading.Tasks.Tests)
  • Name-contract tests pin the identifiers the stitcher hardcodes: V1/V2 dispatch methods, and the V2 continuation wrappers (all 32 exist, none beyond — hardcoded rather than reflected so drift can't pass silently).
  • Frame-capture tests capture the unfiltered physical managed stack from inside a resumed continuation and assert the boundary frames appear in the expected leaf→root order:

    • RuntimeAsync_ResumeDispatchStack (V2 single-yield)
    • StateMachineAsync_ResumeDispatchStack (V1 single-yield)
    • StateMachineAsync_PoolingResumeDispatchStack (V1 pooling → standalone
      AsyncStateMachineDispatcher)
    • StateMachineAsync_InlineCompletionClimb (V1 inline completion, child frames remain beneath the resuming parent)
  • Frame identity is resolved via DiagnosticMethodInfo (stack-trace metadata) rather than StackFrame.GetMethod() (reflection), so the tests work on CoreCLR, Mono, and NativeAOT — the latter trims reflection metadata but preserves stack-trace metadata (including names for [StackTraceHidden] Ecma methods).
Tests are gated by runtime capability: V1 tests run on CoreCLR + Mono; V2 tests run on CoreCLR (+ NativeAOT for the frame-capture test); reflection-based name-contract tests are CoreCLR/Mono only.
Risk / compatibility
  • No change to async dispatch behavior. [StackTraceHidden] only affects stack-trace display, and the newly-hidden V1 InstrumentedMoveNext frames are only present when the async profiler is active.
  • The env-var rename targets an unshipped diagnostic knob, so it is not a breaking change.
@lateralusX
External CPU-callstack stitchers identifies async dispatch and
c16e121
continuation-wrapper frames by method/type name and expects them
to be consistently filtered from managed stack traces. Nothing
in the runtime guarded that implicit contract, so a rename,
an added/removed continuation wrapper, or a lost [StackTraceHidden]
marker could silently break async callstack stitching for both
StateMachineAsync (V1) and RuntimeAsync (V2).
Runtime (System.Private.CoreLib):
- Mark the V1 state-machine dispatch frames [StackTraceHidden]
(InstrumentedMoveNext, MoveNextAsDispatcher, AsyncStateMachineDispatcher.MoveNext)
to match the V2 RuntimeAsync dispatch frames, so they are consistently hidden
from managed stack traces while remaining resolvable by name from stack-trace
metadata.
- Add diagnostic-tooling name-contract comments (unified below the attribute) on
the dispatcher/wrapper methods the stitcher recognizes by name.
- Rename the (unshipped) env var DOTNET_AsyncProfilerEventSource_EventBufferSize
to DOTNET_AsyncProfiler_EventBufferSize for naming consistency; drop a now-unused
using.
Tests (System.Threading.Tasks.Tests):
- Name-contract tests pinning the exact names/count the stitcher hardcodes: V1/V2
dispatch methods and the 32 V2 continuation-wrapper methods (asserting all 32
exist and none beyond).
- Frame-capture tests that capture the UNFILTERED physical managed stack from
inside a resumed continuation and assert the boundary frames appear in the
expected leaf->root order: V2 single-yield, V1 single-yield, V1 pooling, and V1
inline-completion climb. Frame identity is resolved via DiagnosticMethodInfo so
the tests work on CoreCLR, Mono, and NativeAOT (where reflection metadata is
trimmed but stack-trace metadata is not).
CopilotAI
review requested due to automatic review settings
August 6, 2026 19:31
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@lateralusX
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Aug 7, 2026

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/ba-g known issue #131956
@lateralusX
lateralusX
merged commit 45fb46d
into
dotnet:mainAug 7, 2026

146 of 148 checks passed

@dotnet-maestrodotnet-maestroBot
mentioned this pull request
Aug 7, 2026
 Merged

@dotnet-milestone-botdotnet-milestone-botBot
added this to the 11.0-rc1 milestone
Aug 7, 2026
jtschuster pushed a commit
to jtschuster/runtime
that referenced
this pull request
Aug 11, 2026
@lateralusX@jtschuster
Harden async-profiler dispatcher/wrapper frame name contract for call…
b1c50e9
…stack stitching. (dotnet#131963)
## Changes
**Runtime (`System.Private.CoreLib`)**
- Add `[StackTraceHidden]` to the V1 dispatch frames
(`InstrumentedMoveNext`, `MoveNextAsDispatcher`,
`AsyncStateMachineDispatcher.MoveNext`) so V1 matches the already-hidden
V2 dispatch frames. These frames stay out of managed stack traces but
remain in the physical stack and in stack-trace metadata.
- Add name-contract comments (placed uniformly below the attribute) on
the methods and types diagnostic tooling depends on by name.
- Rename the (not-yet-shipped) env var
`DOTNET_AsyncProfilerEventSource_EventBufferSize` →
`DOTNET_AsyncProfiler_EventBufferSize`; remove an unused `using`.
**Tests (`System.Threading.Tasks.Tests`)**
- **Name-contract tests** pin the identifiers the stitcher hardcodes:
V1/V2 dispatch methods, and the V2 continuation wrappers (all 32 exist,
none beyond — hardcoded rather than reflected so drift can't pass
silently).
- **Frame-capture tests** capture the unfiltered physical managed stack
from inside a resumed continuation and assert the boundary frames appear
in the expected leaf→root order:
- `RuntimeAsync_ResumeDispatchStack` (V2 single-yield)
- `StateMachineAsync_ResumeDispatchStack` (V1 single-yield)
- `StateMachineAsync_PoolingResumeDispatchStack` (V1 pooling →
standalone
`AsyncStateMachineDispatcher`)
- `StateMachineAsync_InlineCompletionClimb` (V1 inline completion, child
frames remain beneath the resuming parent)
- Frame identity is resolved via `DiagnosticMethodInfo` (stack-trace
metadata) rather than `StackFrame.GetMethod()` (reflection), so the
tests work on CoreCLR, Mono, and NativeAOT — the latter trims reflection
metadata but preserves stack-trace metadata (including names for
`[StackTraceHidden]` Ecma methods).
Tests are gated by runtime capability: V1 tests run on CoreCLR + Mono;
V2 tests run on CoreCLR (+ NativeAOT for the frame-capture test);
reflection-based name-contract tests are CoreCLR/Mono only.
## Risk / compatibility
- No change to async dispatch behavior. `[StackTraceHidden]` only
affects stack-trace *display*, and the newly-hidden V1
`InstrumentedMoveNext` frames are only present when the async profiler
is active.
- The env-var rename targets an unshipped diagnostic knob, so it is not
a breaking change.
@steveisoksteveisok
mentioned this pull request
Aug 11, 2026

Closed

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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
Harden async-profiler dispatcher/wrapper frame name contract for callstack stitching. - #131963
Merged
lateralusX merged 1 commit into
dotnet:mainfrom 
lateralusX:lateralusX/async-profiler-contract-validation
Aug 7, 2026
Merged
Harden async-profiler dispatcher/wrapper frame name contract for callstack stitching.#131963
lateralusX merged 1 commit into
dotnet:mainfrom 
lateralusX:lateralusX/async-profiler-contract-validation
Conversation
@lateralusX
@lateralusXlateralusX
commented
Aug 6, 2026

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Changes
Runtime (System.Private.CoreLib)
  • Add [StackTraceHidden] to the V1 dispatch frames (InstrumentedMoveNext, MoveNextAsDispatcher, AsyncStateMachineDispatcher.MoveNext) so V1 matches the already-hidden V2 dispatch frames. These frames stay out of managed stack traces but remain in the physical stack and in stack-trace metadata.
  • Add name-contract comments (placed uniformly below the attribute) on the methods and types diagnostic tooling depends on by name.
  • Rename the (not-yet-shipped) env var DOTNET_AsyncProfilerEventSource_EventBufferSize → DOTNET_AsyncProfiler_EventBufferSize; remove an unused using.
Tests (System.Threading.Tasks.Tests)
  • Name-contract tests pin the identifiers the stitcher hardcodes: V1/V2 dispatch methods, and the V2 continuation wrappers (all 32 exist, none beyond — hardcoded rather than reflected so drift can't pass silently).
  • Frame-capture tests capture the unfiltered physical managed stack from inside a resumed continuation and assert the boundary frames appear in the expected leaf→root order:

    • RuntimeAsync_ResumeDispatchStack (V2 single-yield)
    • StateMachineAsync_ResumeDispatchStack (V1 single-yield)
    • StateMachineAsync_PoolingResumeDispatchStack (V1 pooling → standalone
      AsyncStateMachineDispatcher)
    • StateMachineAsync_InlineCompletionClimb (V1 inline completion, child frames remain beneath the resuming parent)
  • Frame identity is resolved via DiagnosticMethodInfo (stack-trace metadata) rather than StackFrame.GetMethod() (reflection), so the tests work on CoreCLR, Mono, and NativeAOT — the latter trims reflection metadata but preserves stack-trace metadata (including names for [StackTraceHidden] Ecma methods).
Tests are gated by runtime capability: V1 tests run on CoreCLR + Mono; V2 tests run on CoreCLR (+ NativeAOT for the frame-capture test); reflection-based name-contract tests are CoreCLR/Mono only.
Risk / compatibility
  • No change to async dispatch behavior. [StackTraceHidden] only affects stack-trace display, and the newly-hidden V1 InstrumentedMoveNext frames are only present when the async profiler is active.
  • The env-var rename targets an unshipped diagnostic knob, so it is not a breaking change.
@lateralusX
External CPU-callstack stitchers identifies async dispatch and
c16e121
continuation-wrapper frames by method/type name and expects them
to be consistently filtered from managed stack traces. Nothing
in the runtime guarded that implicit contract, so a rename,
an added/removed continuation wrapper, or a lost [StackTraceHidden]
marker could silently break async callstack stitching for both
StateMachineAsync (V1) and RuntimeAsync (V2).
Runtime (System.Private.CoreLib):
- Mark the V1 state-machine dispatch frames [StackTraceHidden]
(InstrumentedMoveNext, MoveNextAsDispatcher, AsyncStateMachineDispatcher.MoveNext)
to match the V2 RuntimeAsync dispatch frames, so they are consistently hidden
from managed stack traces while remaining resolvable by name from stack-trace
metadata.
- Add diagnostic-tooling name-contract comments (unified below the attribute) on
the dispatcher/wrapper methods the stitcher recognizes by name.
- Rename the (unshipped) env var DOTNET_AsyncProfilerEventSource_EventBufferSize
to DOTNET_AsyncProfiler_EventBufferSize for naming consistency; drop a now-unused
using.
Tests (System.Threading.Tasks.Tests):
- Name-contract tests pinning the exact names/count the stitcher hardcodes: V1/V2
dispatch methods and the 32 V2 continuation-wrapper methods (asserting all 32
exist and none beyond).
- Frame-capture tests that capture the UNFILTERED physical managed stack from
inside a resumed continuation and assert the boundary frames appear in the
expected leaf->root order: V2 single-yield, V1 single-yield, V1 pooling, and V1
inline-completion climb. Frame identity is resolved via DiagnosticMethodInfo so
the tests work on CoreCLR, Mono, and NativeAOT (where reflection metadata is
trimmed but stack-trace metadata is not).
CopilotAI
review requested due to automatic review settings
August 6, 2026 19:31
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@lateralusX
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MemberAuthor
/ba-g known issue #131956
@lateralusX
lateralusX
merged commit 45fb46d
into
dotnet:mainAug 7, 2026

146 of 148 checks passed

@dotnet-maestrodotnet-maestroBot
mentioned this pull request
Aug 7, 2026
 Merged

@dotnet-milestone-botdotnet-milestone-botBot
added this to the 11.0-rc1 milestone
Aug 7, 2026
jtschuster pushed a commit
to jtschuster/runtime
that referenced
this pull request
Aug 11, 2026
@lateralusX@jtschuster
Harden async-profiler dispatcher/wrapper frame name contract for call…
b1c50e9
…stack stitching. (dotnet#131963)
## Changes
**Runtime (`System.Private.CoreLib`)**
- Add `[StackTraceHidden]` to the V1 dispatch frames
(`InstrumentedMoveNext`, `MoveNextAsDispatcher`,
`AsyncStateMachineDispatcher.MoveNext`) so V1 matches the already-hidden
V2 dispatch frames. These frames stay out of managed stack traces but
remain in the physical stack and in stack-trace metadata.
- Add name-contract comments (placed uniformly below the attribute) on
the methods and types diagnostic tooling depends on by name.
- Rename the (not-yet-shipped) env var
`DOTNET_AsyncProfilerEventSource_EventBufferSize` →
`DOTNET_AsyncProfiler_EventBufferSize`; remove an unused `using`.
**Tests (`System.Threading.Tasks.Tests`)**
- **Name-contract tests** pin the identifiers the stitcher hardcodes:
V1/V2 dispatch methods, and the V2 continuation wrappers (all 32 exist,
none beyond — hardcoded rather than reflected so drift can't pass
silently).
- **Frame-capture tests** capture the unfiltered physical managed stack
from inside a resumed continuation and assert the boundary frames appear
in the expected leaf→root order:
- `RuntimeAsync_ResumeDispatchStack` (V2 single-yield)
- `StateMachineAsync_ResumeDispatchStack` (V1 single-yield)
- `StateMachineAsync_PoolingResumeDispatchStack` (V1 pooling →
standalone
`AsyncStateMachineDispatcher`)
- `StateMachineAsync_InlineCompletionClimb` (V1 inline completion, child
frames remain beneath the resuming parent)
- Frame identity is resolved via `DiagnosticMethodInfo` (stack-trace
metadata) rather than `StackFrame.GetMethod()` (reflection), so the
tests work on CoreCLR, Mono, and NativeAOT — the latter trims reflection
metadata but preserves stack-trace metadata (including names for
`[StackTraceHidden]` Ecma methods).
Tests are gated by runtime capability: V1 tests run on CoreCLR + Mono;
V2 tests run on CoreCLR (+ NativeAOT for the frame-capture test);
reflection-based name-contract tests are CoreCLR/Mono only.
## Risk / compatibility
- No change to async dispatch behavior. `[StackTraceHidden]` only
affects stack-trace *display*, and the newly-hidden V1
`InstrumentedMoveNext` frames are only present when the async profiler
is active.
- The env-var rename targets an unshipped diagnostic knob, so it is not
a breaking change.
@steveisoksteveisok
mentioned this pull request
Aug 11, 2026

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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
Harden async-profiler dispatcher/wrapper frame name contract for callstack stitching. - #131963
Merged
lateralusX merged 1 commit into
dotnet:mainfrom 
lateralusX:lateralusX/async-profiler-contract-validation
Aug 7, 2026
Merged
Harden async-profiler dispatcher/wrapper frame name contract for callstack stitching.#131963
lateralusX merged 1 commit into
dotnet:mainfrom 
lateralusX:lateralusX/async-profiler-contract-validation
Conversation
@lateralusX
@lateralusXlateralusX
commented
Aug 6, 2026

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Changes
Runtime (System.Private.CoreLib)
  • Add [StackTraceHidden] to the V1 dispatch frames (InstrumentedMoveNext, MoveNextAsDispatcher, AsyncStateMachineDispatcher.MoveNext) so V1 matches the already-hidden V2 dispatch frames. These frames stay out of managed stack traces but remain in the physical stack and in stack-trace metadata.
  • Add name-contract comments (placed uniformly below the attribute) on the methods and types diagnostic tooling depends on by name.
  • Rename the (not-yet-shipped) env var DOTNET_AsyncProfilerEventSource_EventBufferSize → DOTNET_AsyncProfiler_EventBufferSize; remove an unused using.
Tests (System.Threading.Tasks.Tests)
  • Name-contract tests pin the identifiers the stitcher hardcodes: V1/V2 dispatch methods, and the V2 continuation wrappers (all 32 exist, none beyond — hardcoded rather than reflected so drift can't pass silently).
  • Frame-capture tests capture the unfiltered physical managed stack from inside a resumed continuation and assert the boundary frames appear in the expected leaf→root order:

    • RuntimeAsync_ResumeDispatchStack (V2 single-yield)
    • StateMachineAsync_ResumeDispatchStack (V1 single-yield)
    • StateMachineAsync_PoolingResumeDispatchStack (V1 pooling → standalone
      AsyncStateMachineDispatcher)
    • StateMachineAsync_InlineCompletionClimb (V1 inline completion, child frames remain beneath the resuming parent)
  • Frame identity is resolved via DiagnosticMethodInfo (stack-trace metadata) rather than StackFrame.GetMethod() (reflection), so the tests work on CoreCLR, Mono, and NativeAOT — the latter trims reflection metadata but preserves stack-trace metadata (including names for [StackTraceHidden] Ecma methods).
Tests are gated by runtime capability: V1 tests run on CoreCLR + Mono; V2 tests run on CoreCLR (+ NativeAOT for the frame-capture test); reflection-based name-contract tests are CoreCLR/Mono only.
Risk / compatibility
  • No change to async dispatch behavior. [StackTraceHidden] only affects stack-trace display, and the newly-hidden V1 InstrumentedMoveNext frames are only present when the async profiler is active.
  • The env-var rename targets an unshipped diagnostic knob, so it is not a breaking change.
@lateralusX
External CPU-callstack stitchers identifies async dispatch and
c16e121
continuation-wrapper frames by method/type name and expects them
to be consistently filtered from managed stack traces. Nothing
in the runtime guarded that implicit contract, so a rename,
an added/removed continuation wrapper, or a lost [StackTraceHidden]
marker could silently break async callstack stitching for both
StateMachineAsync (V1) and RuntimeAsync (V2).
Runtime (System.Private.CoreLib):
- Mark the V1 state-machine dispatch frames [StackTraceHidden]
(InstrumentedMoveNext, MoveNextAsDispatcher, AsyncStateMachineDispatcher.MoveNext)
to match the V2 RuntimeAsync dispatch frames, so they are consistently hidden
from managed stack traces while remaining resolvable by name from stack-trace
metadata.
- Add diagnostic-tooling name-contract comments (unified below the attribute) on
the dispatcher/wrapper methods the stitcher recognizes by name.
- Rename the (unshipped) env var DOTNET_AsyncProfilerEventSource_EventBufferSize
to DOTNET_AsyncProfiler_EventBufferSize for naming consistency; drop a now-unused
using.
Tests (System.Threading.Tasks.Tests):
- Name-contract tests pinning the exact names/count the stitcher hardcodes: V1/V2
dispatch methods and the 32 V2 continuation-wrapper methods (asserting all 32
exist and none beyond).
- Frame-capture tests that capture the UNFILTERED physical managed stack from
inside a resumed continuation and assert the boundary frames appear in the
expected leaf->root order: V2 single-yield, V1 single-yield, V1 pooling, and V1
inline-completion climb. Frame identity is resolved via DiagnosticMethodInfo so
the tests work on CoreCLR, Mono, and NativeAOT (where reflection metadata is
trimmed but stack-trace metadata is not).
CopilotAI
review requested due to automatic review settings
August 6, 2026 19:31
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Successfully started running 3 pipeline(s).

13 pipeline(s) were filtered out due to trigger conditions.

There may be pipelines that require an authorized user to comment /azp run to run.
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Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.
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This error may be related to your runner configuration. You can now configure runners for Copilot code review separately from Copilot cloud agent by creating a copilot-code-review.yml file with your setup steps. Read the docs for details.
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Tagging subscribers to this area: @dotnet/area-system-runtime-compilerservices

See info in area-owners.md if you want to be subscribed.
noahfalk
noahfalk
approved these changes
Aug 7, 2026
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👍
@lateralusX
lateralusX
commented
Aug 7, 2026

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MemberAuthor
/ba-g known issue #131956
@lateralusX
lateralusX
merged commit 45fb46d
into
dotnet:mainAug 7, 2026

146 of 148 checks passed

@dotnet-maestrodotnet-maestroBot
mentioned this pull request
Aug 7, 2026
 Merged

@dotnet-milestone-botdotnet-milestone-botBot
added this to the 11.0-rc1 milestone
Aug 7, 2026
jtschuster pushed a commit
to jtschuster/runtime
that referenced
this pull request
Aug 11, 2026
@lateralusX@jtschuster
Harden async-profiler dispatcher/wrapper frame name contract for call…
b1c50e9
…stack stitching. (dotnet#131963)
## Changes
**Runtime (`System.Private.CoreLib`)**
- Add `[StackTraceHidden]` to the V1 dispatch frames
(`InstrumentedMoveNext`, `MoveNextAsDispatcher`,
`AsyncStateMachineDispatcher.MoveNext`) so V1 matches the already-hidden
V2 dispatch frames. These frames stay out of managed stack traces but
remain in the physical stack and in stack-trace metadata.
- Add name-contract comments (placed uniformly below the attribute) on
the methods and types diagnostic tooling depends on by name.
- Rename the (not-yet-shipped) env var
`DOTNET_AsyncProfilerEventSource_EventBufferSize` →
`DOTNET_AsyncProfiler_EventBufferSize`; remove an unused `using`.
**Tests (`System.Threading.Tasks.Tests`)**
- **Name-contract tests** pin the identifiers the stitcher hardcodes:
V1/V2 dispatch methods, and the V2 continuation wrappers (all 32 exist,
none beyond — hardcoded rather than reflected so drift can't pass
silently).
- **Frame-capture tests** capture the unfiltered physical managed stack
from inside a resumed continuation and assert the boundary frames appear
in the expected leaf→root order:
- `RuntimeAsync_ResumeDispatchStack` (V2 single-yield)
- `StateMachineAsync_ResumeDispatchStack` (V1 single-yield)
- `StateMachineAsync_PoolingResumeDispatchStack` (V1 pooling →
standalone
`AsyncStateMachineDispatcher`)
- `StateMachineAsync_InlineCompletionClimb` (V1 inline completion, child
frames remain beneath the resuming parent)
- Frame identity is resolved via `DiagnosticMethodInfo` (stack-trace
metadata) rather than `StackFrame.GetMethod()` (reflection), so the
tests work on CoreCLR, Mono, and NativeAOT — the latter trims reflection
metadata but preserves stack-trace metadata (including names for
`[StackTraceHidden]` Ecma methods).
Tests are gated by runtime capability: V1 tests run on CoreCLR + Mono;
V2 tests run on CoreCLR (+ NativeAOT for the frame-capture test);
reflection-based name-contract tests are CoreCLR/Mono only.
## Risk / compatibility
- No change to async dispatch behavior. `[StackTraceHidden]` only
affects stack-trace *display*, and the newly-hidden V1
`InstrumentedMoveNext` frames are only present when the async profiler
is active.
- The env-var rename targets an unshipped diagnostic knob, so it is not
a breaking change.
@steveisoksteveisok
mentioned this pull request
Aug 11, 2026

Closed

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@lateralusX@noahfalk

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

Skip to content
Harden async-profiler dispatcher/wrapper frame name contract for callstack stitching. - #131963
Merged
lateralusX merged 1 commit into
dotnet:mainfrom 
lateralusX:lateralusX/async-profiler-contract-validation
Aug 7, 2026
Merged
Harden async-profiler dispatcher/wrapper frame name contract for callstack stitching.#131963
lateralusX merged 1 commit into
dotnet:mainfrom 
lateralusX:lateralusX/async-profiler-contract-validation
Conversation
@lateralusX
@lateralusXlateralusX
commented
Aug 6, 2026

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Changes
Runtime (System.Private.CoreLib)
  • Add [StackTraceHidden] to the V1 dispatch frames (InstrumentedMoveNext, MoveNextAsDispatcher, AsyncStateMachineDispatcher.MoveNext) so V1 matches the already-hidden V2 dispatch frames. These frames stay out of managed stack traces but remain in the physical stack and in stack-trace metadata.
  • Add name-contract comments (placed uniformly below the attribute) on the methods and types diagnostic tooling depends on by name.
  • Rename the (not-yet-shipped) env var DOTNET_AsyncProfilerEventSource_EventBufferSize → DOTNET_AsyncProfiler_EventBufferSize; remove an unused using.
Tests (System.Threading.Tasks.Tests)
  • Name-contract tests pin the identifiers the stitcher hardcodes: V1/V2 dispatch methods, and the V2 continuation wrappers (all 32 exist, none beyond — hardcoded rather than reflected so drift can't pass silently).
  • Frame-capture tests capture the unfiltered physical managed stack from inside a resumed continuation and assert the boundary frames appear in the expected leaf→root order:

    • RuntimeAsync_ResumeDispatchStack (V2 single-yield)
    • StateMachineAsync_ResumeDispatchStack (V1 single-yield)
    • StateMachineAsync_PoolingResumeDispatchStack (V1 pooling → standalone
      AsyncStateMachineDispatcher)
    • StateMachineAsync_InlineCompletionClimb (V1 inline completion, child frames remain beneath the resuming parent)
  • Frame identity is resolved via DiagnosticMethodInfo (stack-trace metadata) rather than StackFrame.GetMethod() (reflection), so the tests work on CoreCLR, Mono, and NativeAOT — the latter trims reflection metadata but preserves stack-trace metadata (including names for [StackTraceHidden] Ecma methods).
Tests are gated by runtime capability: V1 tests run on CoreCLR + Mono; V2 tests run on CoreCLR (+ NativeAOT for the frame-capture test); reflection-based name-contract tests are CoreCLR/Mono only.
Risk / compatibility
  • No change to async dispatch behavior. [StackTraceHidden] only affects stack-trace display, and the newly-hidden V1 InstrumentedMoveNext frames are only present when the async profiler is active.
  • The env-var rename targets an unshipped diagnostic knob, so it is not a breaking change.
@lateralusX
External CPU-callstack stitchers identifies async dispatch and
c16e121
continuation-wrapper frames by method/type name and expects them
to be consistently filtered from managed stack traces. Nothing
in the runtime guarded that implicit contract, so a rename,
an added/removed continuation wrapper, or a lost [StackTraceHidden]
marker could silently break async callstack stitching for both
StateMachineAsync (V1) and RuntimeAsync (V2).
Runtime (System.Private.CoreLib):
- Mark the V1 state-machine dispatch frames [StackTraceHidden]
(InstrumentedMoveNext, MoveNextAsDispatcher, AsyncStateMachineDispatcher.MoveNext)
to match the V2 RuntimeAsync dispatch frames, so they are consistently hidden
from managed stack traces while remaining resolvable by name from stack-trace
metadata.
- Add diagnostic-tooling name-contract comments (unified below the attribute) on
the dispatcher/wrapper methods the stitcher recognizes by name.
- Rename the (unshipped) env var DOTNET_AsyncProfilerEventSource_EventBufferSize
to DOTNET_AsyncProfiler_EventBufferSize for naming consistency; drop a now-unused
using.
Tests (System.Threading.Tasks.Tests):
- Name-contract tests pinning the exact names/count the stitcher hardcodes: V1/V2
dispatch methods and the 32 V2 continuation-wrapper methods (asserting all 32
exist and none beyond).
- Frame-capture tests that capture the UNFILTERED physical managed stack from
inside a resumed continuation and assert the boundary frames appear in the
expected leaf->root order: V2 single-yield, V1 single-yield, V1 pooling, and V1
inline-completion climb. Frame identity is resolved via DiagnosticMethodInfo so
the tests work on CoreCLR, Mono, and NativeAOT (where reflection metadata is
trimmed but stack-trace metadata is not).
CopilotAI
review requested due to automatic review settings
August 6, 2026 19:31
@azure-pipelines
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commented
Aug 6, 2026

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Azure Pipelines:

Successfully started running 3 pipeline(s).

13 pipeline(s) were filtered out due to trigger conditions.

There may be pipelines that require an authorized user to comment /azp run to run.
CopilotAI
reviewed
Aug 6, 2026
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Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.
Note
This error may be related to your runner configuration. You can now configure runners for Copilot code review separately from Copilot cloud agent by creating a copilot-code-review.yml file with your setup steps. Read the docs for details.
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Tagging subscribers to this area: @dotnet/area-system-runtime-compilerservices

See info in area-owners.md if you want to be subscribed.
noahfalk
noahfalk
approved these changes
Aug 7, 2026
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👍
@lateralusX
lateralusX
commented
Aug 7, 2026

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MemberAuthor
/ba-g known issue #131956
@lateralusX
lateralusX
merged commit 45fb46d
into
dotnet:mainAug 7, 2026

146 of 148 checks passed

@dotnet-maestrodotnet-maestroBot
mentioned this pull request
Aug 7, 2026
 Merged

@dotnet-milestone-botdotnet-milestone-botBot
added this to the 11.0-rc1 milestone
Aug 7, 2026
jtschuster pushed a commit
to jtschuster/runtime
that referenced
this pull request
Aug 11, 2026
@lateralusX@jtschuster
Harden async-profiler dispatcher/wrapper frame name contract for call…
b1c50e9
…stack stitching. (dotnet#131963)
## Changes
**Runtime (`System.Private.CoreLib`)**
- Add `[StackTraceHidden]` to the V1 dispatch frames
(`InstrumentedMoveNext`, `MoveNextAsDispatcher`,
`AsyncStateMachineDispatcher.MoveNext`) so V1 matches the already-hidden
V2 dispatch frames. These frames stay out of managed stack traces but
remain in the physical stack and in stack-trace metadata.
- Add name-contract comments (placed uniformly below the attribute) on
the methods and types diagnostic tooling depends on by name.
- Rename the (not-yet-shipped) env var
`DOTNET_AsyncProfilerEventSource_EventBufferSize` →
`DOTNET_AsyncProfiler_EventBufferSize`; remove an unused `using`.
**Tests (`System.Threading.Tasks.Tests`)**
- **Name-contract tests** pin the identifiers the stitcher hardcodes:
V1/V2 dispatch methods, and the V2 continuation wrappers (all 32 exist,
none beyond — hardcoded rather than reflected so drift can't pass
silently).
- **Frame-capture tests** capture the unfiltered physical managed stack
from inside a resumed continuation and assert the boundary frames appear
in the expected leaf→root order:
- `RuntimeAsync_ResumeDispatchStack` (V2 single-yield)
- `StateMachineAsync_ResumeDispatchStack` (V1 single-yield)
- `StateMachineAsync_PoolingResumeDispatchStack` (V1 pooling →
standalone
`AsyncStateMachineDispatcher`)
- `StateMachineAsync_InlineCompletionClimb` (V1 inline completion, child
frames remain beneath the resuming parent)
- Frame identity is resolved via `DiagnosticMethodInfo` (stack-trace
metadata) rather than `StackFrame.GetMethod()` (reflection), so the
tests work on CoreCLR, Mono, and NativeAOT — the latter trims reflection
metadata but preserves stack-trace metadata (including names for
`[StackTraceHidden]` Ecma methods).
Tests are gated by runtime capability: V1 tests run on CoreCLR + Mono;
V2 tests run on CoreCLR (+ NativeAOT for the frame-capture test);
reflection-based name-contract tests are CoreCLR/Mono only.
## Risk / compatibility
- No change to async dispatch behavior. `[StackTraceHidden]` only
affects stack-trace *display*, and the newly-hidden V1
`InstrumentedMoveNext` frames are only present when the async profiler
is active.
- The env-var rename targets an unshipped diagnostic knob, so it is not
a breaking change.
@steveisoksteveisok
mentioned this pull request
Aug 11, 2026

Closed

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@noahfalknoahfalknoahfalk approved these changes

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@lateralusX@noahfalk

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
Harden async-profiler dispatcher/wrapper frame name contract for callstack stitching. - #131963
Merged
lateralusX merged 1 commit into
dotnet:mainfrom 
lateralusX:lateralusX/async-profiler-contract-validation
Aug 7, 2026
Merged
Harden async-profiler dispatcher/wrapper frame name contract for callstack stitching.#131963
lateralusX merged 1 commit into
dotnet:mainfrom 
lateralusX:lateralusX/async-profiler-contract-validation
Conversation
@lateralusX
@lateralusXlateralusX
commented
Aug 6, 2026

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Changes
Runtime (System.Private.CoreLib)
  • Add [StackTraceHidden] to the V1 dispatch frames (InstrumentedMoveNext, MoveNextAsDispatcher, AsyncStateMachineDispatcher.MoveNext) so V1 matches the already-hidden V2 dispatch frames. These frames stay out of managed stack traces but remain in the physical stack and in stack-trace metadata.
  • Add name-contract comments (placed uniformly below the attribute) on the methods and types diagnostic tooling depends on by name.
  • Rename the (not-yet-shipped) env var DOTNET_AsyncProfilerEventSource_EventBufferSize → DOTNET_AsyncProfiler_EventBufferSize; remove an unused using.
Tests (System.Threading.Tasks.Tests)
  • Name-contract tests pin the identifiers the stitcher hardcodes: V1/V2 dispatch methods, and the V2 continuation wrappers (all 32 exist, none beyond — hardcoded rather than reflected so drift can't pass silently).
  • Frame-capture tests capture the unfiltered physical managed stack from inside a resumed continuation and assert the boundary frames appear in the expected leaf→root order:

    • RuntimeAsync_ResumeDispatchStack (V2 single-yield)
    • StateMachineAsync_ResumeDispatchStack (V1 single-yield)
    • StateMachineAsync_PoolingResumeDispatchStack (V1 pooling → standalone
      AsyncStateMachineDispatcher)
    • StateMachineAsync_InlineCompletionClimb (V1 inline completion, child frames remain beneath the resuming parent)
  • Frame identity is resolved via DiagnosticMethodInfo (stack-trace metadata) rather than StackFrame.GetMethod() (reflection), so the tests work on CoreCLR, Mono, and NativeAOT — the latter trims reflection metadata but preserves stack-trace metadata (including names for [StackTraceHidden] Ecma methods).
Tests are gated by runtime capability: V1 tests run on CoreCLR + Mono; V2 tests run on CoreCLR (+ NativeAOT for the frame-capture test); reflection-based name-contract tests are CoreCLR/Mono only.
Risk / compatibility
  • No change to async dispatch behavior. [StackTraceHidden] only affects stack-trace display, and the newly-hidden V1 InstrumentedMoveNext frames are only present when the async profiler is active.
  • The env-var rename targets an unshipped diagnostic knob, so it is not a breaking change.
@lateralusX
External CPU-callstack stitchers identifies async dispatch and
c16e121
continuation-wrapper frames by method/type name and expects them
to be consistently filtered from managed stack traces. Nothing
in the runtime guarded that implicit contract, so a rename,
an added/removed continuation wrapper, or a lost [StackTraceHidden]
marker could silently break async callstack stitching for both
StateMachineAsync (V1) and RuntimeAsync (V2).
Runtime (System.Private.CoreLib):
- Mark the V1 state-machine dispatch frames [StackTraceHidden]
(InstrumentedMoveNext, MoveNextAsDispatcher, AsyncStateMachineDispatcher.MoveNext)
to match the V2 RuntimeAsync dispatch frames, so they are consistently hidden
from managed stack traces while remaining resolvable by name from stack-trace
metadata.
- Add diagnostic-tooling name-contract comments (unified below the attribute) on
the dispatcher/wrapper methods the stitcher recognizes by name.
- Rename the (unshipped) env var DOTNET_AsyncProfilerEventSource_EventBufferSize
to DOTNET_AsyncProfiler_EventBufferSize for naming consistency; drop a now-unused
using.
Tests (System.Threading.Tasks.Tests):
- Name-contract tests pinning the exact names/count the stitcher hardcodes: V1/V2
dispatch methods and the 32 V2 continuation-wrapper methods (asserting all 32
exist and none beyond).
- Frame-capture tests that capture the UNFILTERED physical managed stack from
inside a resumed continuation and assert the boundary frames appear in the
expected leaf->root order: V2 single-yield, V1 single-yield, V1 pooling, and V1
inline-completion climb. Frame identity is resolved via DiagnosticMethodInfo so
the tests work on CoreCLR, Mono, and NativeAOT (where reflection metadata is
trimmed but stack-trace metadata is not).
CopilotAI
review requested due to automatic review settings
August 6, 2026 19:31
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@lateralusX
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Aug 7, 2026

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/ba-g known issue #131956
@lateralusX
lateralusX
merged commit 45fb46d
into
dotnet:mainAug 7, 2026

146 of 148 checks passed

@dotnet-maestrodotnet-maestroBot
mentioned this pull request
Aug 7, 2026
 Merged

@dotnet-milestone-botdotnet-milestone-botBot
added this to the 11.0-rc1 milestone
Aug 7, 2026
jtschuster pushed a commit
to jtschuster/runtime
that referenced
this pull request
Aug 11, 2026
@lateralusX@jtschuster
Harden async-profiler dispatcher/wrapper frame name contract for call…
b1c50e9
…stack stitching. (dotnet#131963)
## Changes
**Runtime (`System.Private.CoreLib`)**
- Add `[StackTraceHidden]` to the V1 dispatch frames
(`InstrumentedMoveNext`, `MoveNextAsDispatcher`,
`AsyncStateMachineDispatcher.MoveNext`) so V1 matches the already-hidden
V2 dispatch frames. These frames stay out of managed stack traces but
remain in the physical stack and in stack-trace metadata.
- Add name-contract comments (placed uniformly below the attribute) on
the methods and types diagnostic tooling depends on by name.
- Rename the (not-yet-shipped) env var
`DOTNET_AsyncProfilerEventSource_EventBufferSize` →
`DOTNET_AsyncProfiler_EventBufferSize`; remove an unused `using`.
**Tests (`System.Threading.Tasks.Tests`)**
- **Name-contract tests** pin the identifiers the stitcher hardcodes:
V1/V2 dispatch methods, and the V2 continuation wrappers (all 32 exist,
none beyond — hardcoded rather than reflected so drift can't pass
silently).
- **Frame-capture tests** capture the unfiltered physical managed stack
from inside a resumed continuation and assert the boundary frames appear
in the expected leaf→root order:
- `RuntimeAsync_ResumeDispatchStack` (V2 single-yield)
- `StateMachineAsync_ResumeDispatchStack` (V1 single-yield)
- `StateMachineAsync_PoolingResumeDispatchStack` (V1 pooling →
standalone
`AsyncStateMachineDispatcher`)
- `StateMachineAsync_InlineCompletionClimb` (V1 inline completion, child
frames remain beneath the resuming parent)
- Frame identity is resolved via `DiagnosticMethodInfo` (stack-trace
metadata) rather than `StackFrame.GetMethod()` (reflection), so the
tests work on CoreCLR, Mono, and NativeAOT — the latter trims reflection
metadata but preserves stack-trace metadata (including names for
`[StackTraceHidden]` Ecma methods).
Tests are gated by runtime capability: V1 tests run on CoreCLR + Mono;
V2 tests run on CoreCLR (+ NativeAOT for the frame-capture test);
reflection-based name-contract tests are CoreCLR/Mono only.
## Risk / compatibility
- No change to async dispatch behavior. `[StackTraceHidden]` only
affects stack-trace *display*, and the newly-hidden V1
`InstrumentedMoveNext` frames are only present when the async profiler
is active.
- The env-var rename targets an unshipped diagnostic knob, so it is not
a breaking change.
@steveisoksteveisok
mentioned this pull request
Aug 11, 2026

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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
Harden async-profiler dispatcher/wrapper frame name contract for callstack stitching. - #131963
Merged
lateralusX merged 1 commit into
dotnet:mainfrom 
lateralusX:lateralusX/async-profiler-contract-validation
Aug 7, 2026
Merged
Harden async-profiler dispatcher/wrapper frame name contract for callstack stitching.#131963
lateralusX merged 1 commit into
dotnet:mainfrom 
lateralusX:lateralusX/async-profiler-contract-validation
Conversation
@lateralusX
@lateralusXlateralusX
commented
Aug 6, 2026

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Changes
Runtime (System.Private.CoreLib)
  • Add [StackTraceHidden] to the V1 dispatch frames (InstrumentedMoveNext, MoveNextAsDispatcher, AsyncStateMachineDispatcher.MoveNext) so V1 matches the already-hidden V2 dispatch frames. These frames stay out of managed stack traces but remain in the physical stack and in stack-trace metadata.
  • Add name-contract comments (placed uniformly below the attribute) on the methods and types diagnostic tooling depends on by name.
  • Rename the (not-yet-shipped) env var DOTNET_AsyncProfilerEventSource_EventBufferSize → DOTNET_AsyncProfiler_EventBufferSize; remove an unused using.
Tests (System.Threading.Tasks.Tests)
  • Name-contract tests pin the identifiers the stitcher hardcodes: V1/V2 dispatch methods, and the V2 continuation wrappers (all 32 exist, none beyond — hardcoded rather than reflected so drift can't pass silently).
  • Frame-capture tests capture the unfiltered physical managed stack from inside a resumed continuation and assert the boundary frames appear in the expected leaf→root order:

    • RuntimeAsync_ResumeDispatchStack (V2 single-yield)
    • StateMachineAsync_ResumeDispatchStack (V1 single-yield)
    • StateMachineAsync_PoolingResumeDispatchStack (V1 pooling → standalone
      AsyncStateMachineDispatcher)
    • StateMachineAsync_InlineCompletionClimb (V1 inline completion, child frames remain beneath the resuming parent)
  • Frame identity is resolved via DiagnosticMethodInfo (stack-trace metadata) rather than StackFrame.GetMethod() (reflection), so the tests work on CoreCLR, Mono, and NativeAOT — the latter trims reflection metadata but preserves stack-trace metadata (including names for [StackTraceHidden] Ecma methods).
Tests are gated by runtime capability: V1 tests run on CoreCLR + Mono; V2 tests run on CoreCLR (+ NativeAOT for the frame-capture test); reflection-based name-contract tests are CoreCLR/Mono only.
Risk / compatibility
  • No change to async dispatch behavior. [StackTraceHidden] only affects stack-trace display, and the newly-hidden V1 InstrumentedMoveNext frames are only present when the async profiler is active.
  • The env-var rename targets an unshipped diagnostic knob, so it is not a breaking change.
@lateralusX
External CPU-callstack stitchers identifies async dispatch and
c16e121
continuation-wrapper frames by method/type name and expects them
to be consistently filtered from managed stack traces. Nothing
in the runtime guarded that implicit contract, so a rename,
an added/removed continuation wrapper, or a lost [StackTraceHidden]
marker could silently break async callstack stitching for both
StateMachineAsync (V1) and RuntimeAsync (V2).
Runtime (System.Private.CoreLib):
- Mark the V1 state-machine dispatch frames [StackTraceHidden]
(InstrumentedMoveNext, MoveNextAsDispatcher, AsyncStateMachineDispatcher.MoveNext)
to match the V2 RuntimeAsync dispatch frames, so they are consistently hidden
from managed stack traces while remaining resolvable by name from stack-trace
metadata.
- Add diagnostic-tooling name-contract comments (unified below the attribute) on
the dispatcher/wrapper methods the stitcher recognizes by name.
- Rename the (unshipped) env var DOTNET_AsyncProfilerEventSource_EventBufferSize
to DOTNET_AsyncProfiler_EventBufferSize for naming consistency; drop a now-unused
using.
Tests (System.Threading.Tasks.Tests):
- Name-contract tests pinning the exact names/count the stitcher hardcodes: V1/V2
dispatch methods and the 32 V2 continuation-wrapper methods (asserting all 32
exist and none beyond).
- Frame-capture tests that capture the UNFILTERED physical managed stack from
inside a resumed continuation and assert the boundary frames appear in the
expected leaf->root order: V2 single-yield, V1 single-yield, V1 pooling, and V1
inline-completion climb. Frame identity is resolved via DiagnosticMethodInfo so
the tests work on CoreCLR, Mono, and NativeAOT (where reflection metadata is
trimmed but stack-trace metadata is not).
CopilotAI
review requested due to automatic review settings
August 6, 2026 19:31
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Successfully started running 3 pipeline(s).

13 pipeline(s) were filtered out due to trigger conditions.

There may be pipelines that require an authorized user to comment /azp run to run.
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Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.
Note
This error may be related to your runner configuration. You can now configure runners for Copilot code review separately from Copilot cloud agent by creating a copilot-code-review.yml file with your setup steps. Read the docs for details.
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Tagging subscribers to this area: @dotnet/area-system-runtime-compilerservices

See info in area-owners.md if you want to be subscribed.
noahfalk
noahfalk
approved these changes
Aug 7, 2026
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👍
@lateralusX
lateralusX
commented
Aug 7, 2026

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MemberAuthor
/ba-g known issue #131956
@lateralusX
lateralusX
merged commit 45fb46d
into
dotnet:mainAug 7, 2026

146 of 148 checks passed

@dotnet-maestrodotnet-maestroBot
mentioned this pull request
Aug 7, 2026
 Merged

@dotnet-milestone-botdotnet-milestone-botBot
added this to the 11.0-rc1 milestone
Aug 7, 2026
jtschuster pushed a commit
to jtschuster/runtime
that referenced
this pull request
Aug 11, 2026
@lateralusX@jtschuster
Harden async-profiler dispatcher/wrapper frame name contract for call…
b1c50e9
…stack stitching. (dotnet#131963)
## Changes
**Runtime (`System.Private.CoreLib`)**
- Add `[StackTraceHidden]` to the V1 dispatch frames
(`InstrumentedMoveNext`, `MoveNextAsDispatcher`,
`AsyncStateMachineDispatcher.MoveNext`) so V1 matches the already-hidden
V2 dispatch frames. These frames stay out of managed stack traces but
remain in the physical stack and in stack-trace metadata.
- Add name-contract comments (placed uniformly below the attribute) on
the methods and types diagnostic tooling depends on by name.
- Rename the (not-yet-shipped) env var
`DOTNET_AsyncProfilerEventSource_EventBufferSize` →
`DOTNET_AsyncProfiler_EventBufferSize`; remove an unused `using`.
**Tests (`System.Threading.Tasks.Tests`)**
- **Name-contract tests** pin the identifiers the stitcher hardcodes:
V1/V2 dispatch methods, and the V2 continuation wrappers (all 32 exist,
none beyond — hardcoded rather than reflected so drift can't pass
silently).
- **Frame-capture tests** capture the unfiltered physical managed stack
from inside a resumed continuation and assert the boundary frames appear
in the expected leaf→root order:
- `RuntimeAsync_ResumeDispatchStack` (V2 single-yield)
- `StateMachineAsync_ResumeDispatchStack` (V1 single-yield)
- `StateMachineAsync_PoolingResumeDispatchStack` (V1 pooling →
standalone
`AsyncStateMachineDispatcher`)
- `StateMachineAsync_InlineCompletionClimb` (V1 inline completion, child
frames remain beneath the resuming parent)
- Frame identity is resolved via `DiagnosticMethodInfo` (stack-trace
metadata) rather than `StackFrame.GetMethod()` (reflection), so the
tests work on CoreCLR, Mono, and NativeAOT — the latter trims reflection
metadata but preserves stack-trace metadata (including names for
`[StackTraceHidden]` Ecma methods).
Tests are gated by runtime capability: V1 tests run on CoreCLR + Mono;
V2 tests run on CoreCLR (+ NativeAOT for the frame-capture test);
reflection-based name-contract tests are CoreCLR/Mono only.
## Risk / compatibility
- No change to async dispatch behavior. `[StackTraceHidden]` only
affects stack-trace *display*, and the newly-hidden V1
`InstrumentedMoveNext` frames are only present when the async profiler
is active.
- The env-var rename targets an unshipped diagnostic knob, so it is not
a breaking change.
@steveisoksteveisok
mentioned this pull request
Aug 11, 2026

Closed

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3 participants

@lateralusX@noahfalk

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

Skip to content
Harden async-profiler dispatcher/wrapper frame name contract for callstack stitching. - #131963
Merged
lateralusX merged 1 commit into
dotnet:mainfrom 
lateralusX:lateralusX/async-profiler-contract-validation
Aug 7, 2026
Merged
Harden async-profiler dispatcher/wrapper frame name contract for callstack stitching.#131963
lateralusX merged 1 commit into
dotnet:mainfrom 
lateralusX:lateralusX/async-profiler-contract-validation
Conversation
@lateralusX
@lateralusXlateralusX
commented
Aug 6, 2026

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Changes
Runtime (System.Private.CoreLib)
  • Add [StackTraceHidden] to the V1 dispatch frames (InstrumentedMoveNext, MoveNextAsDispatcher, AsyncStateMachineDispatcher.MoveNext) so V1 matches the already-hidden V2 dispatch frames. These frames stay out of managed stack traces but remain in the physical stack and in stack-trace metadata.
  • Add name-contract comments (placed uniformly below the attribute) on the methods and types diagnostic tooling depends on by name.
  • Rename the (not-yet-shipped) env var DOTNET_AsyncProfilerEventSource_EventBufferSize → DOTNET_AsyncProfiler_EventBufferSize; remove an unused using.
Tests (System.Threading.Tasks.Tests)
  • Name-contract tests pin the identifiers the stitcher hardcodes: V1/V2 dispatch methods, and the V2 continuation wrappers (all 32 exist, none beyond — hardcoded rather than reflected so drift can't pass silently).
  • Frame-capture tests capture the unfiltered physical managed stack from inside a resumed continuation and assert the boundary frames appear in the expected leaf→root order:

    • RuntimeAsync_ResumeDispatchStack (V2 single-yield)
    • StateMachineAsync_ResumeDispatchStack (V1 single-yield)
    • StateMachineAsync_PoolingResumeDispatchStack (V1 pooling → standalone
      AsyncStateMachineDispatcher)
    • StateMachineAsync_InlineCompletionClimb (V1 inline completion, child frames remain beneath the resuming parent)
  • Frame identity is resolved via DiagnosticMethodInfo (stack-trace metadata) rather than StackFrame.GetMethod() (reflection), so the tests work on CoreCLR, Mono, and NativeAOT — the latter trims reflection metadata but preserves stack-trace metadata (including names for [StackTraceHidden] Ecma methods).
Tests are gated by runtime capability: V1 tests run on CoreCLR + Mono; V2 tests run on CoreCLR (+ NativeAOT for the frame-capture test); reflection-based name-contract tests are CoreCLR/Mono only.
Risk / compatibility
  • No change to async dispatch behavior. [StackTraceHidden] only affects stack-trace display, and the newly-hidden V1 InstrumentedMoveNext frames are only present when the async profiler is active.
  • The env-var rename targets an unshipped diagnostic knob, so it is not a breaking change.
@lateralusX
External CPU-callstack stitchers identifies async dispatch and
c16e121
continuation-wrapper frames by method/type name and expects them
to be consistently filtered from managed stack traces. Nothing
in the runtime guarded that implicit contract, so a rename,
an added/removed continuation wrapper, or a lost [StackTraceHidden]
marker could silently break async callstack stitching for both
StateMachineAsync (V1) and RuntimeAsync (V2).
Runtime (System.Private.CoreLib):
- Mark the V1 state-machine dispatch frames [StackTraceHidden]
(InstrumentedMoveNext, MoveNextAsDispatcher, AsyncStateMachineDispatcher.MoveNext)
to match the V2 RuntimeAsync dispatch frames, so they are consistently hidden
from managed stack traces while remaining resolvable by name from stack-trace
metadata.
- Add diagnostic-tooling name-contract comments (unified below the attribute) on
the dispatcher/wrapper methods the stitcher recognizes by name.
- Rename the (unshipped) env var DOTNET_AsyncProfilerEventSource_EventBufferSize
to DOTNET_AsyncProfiler_EventBufferSize for naming consistency; drop a now-unused
using.
Tests (System.Threading.Tasks.Tests):
- Name-contract tests pinning the exact names/count the stitcher hardcodes: V1/V2
dispatch methods and the 32 V2 continuation-wrapper methods (asserting all 32
exist and none beyond).
- Frame-capture tests that capture the UNFILTERED physical managed stack from
inside a resumed continuation and assert the boundary frames appear in the
expected leaf->root order: V2 single-yield, V1 single-yield, V1 pooling, and V1
inline-completion climb. Frame identity is resolved via DiagnosticMethodInfo so
the tests work on CoreCLR, Mono, and NativeAOT (where reflection metadata is
trimmed but stack-trace metadata is not).
CopilotAI
review requested due to automatic review settings
August 6, 2026 19:31
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noahfalk
noahfalk
approved these changes
Aug 7, 2026
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👍
@lateralusX
lateralusX
commented
Aug 7, 2026

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MemberAuthor
/ba-g known issue #131956
@lateralusX
lateralusX
merged commit 45fb46d
into
dotnet:mainAug 7, 2026

146 of 148 checks passed

@dotnet-maestrodotnet-maestroBot
mentioned this pull request
Aug 7, 2026
 Merged

@dotnet-milestone-botdotnet-milestone-botBot
added this to the 11.0-rc1 milestone
Aug 7, 2026
jtschuster pushed a commit
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Aug 11, 2026
@lateralusX@jtschuster
Harden async-profiler dispatcher/wrapper frame name contract for call…
b1c50e9
…stack stitching. (dotnet#131963)
## Changes
**Runtime (`System.Private.CoreLib`)**
- Add `[StackTraceHidden]` to the V1 dispatch frames
(`InstrumentedMoveNext`, `MoveNextAsDispatcher`,
`AsyncStateMachineDispatcher.MoveNext`) so V1 matches the already-hidden
V2 dispatch frames. These frames stay out of managed stack traces but
remain in the physical stack and in stack-trace metadata.
- Add name-contract comments (placed uniformly below the attribute) on
the methods and types diagnostic tooling depends on by name.
- Rename the (not-yet-shipped) env var
`DOTNET_AsyncProfilerEventSource_EventBufferSize` →
`DOTNET_AsyncProfiler_EventBufferSize`; remove an unused `using`.
**Tests (`System.Threading.Tasks.Tests`)**
- **Name-contract tests** pin the identifiers the stitcher hardcodes:
V1/V2 dispatch methods, and the V2 continuation wrappers (all 32 exist,
none beyond — hardcoded rather than reflected so drift can't pass
silently).
- **Frame-capture tests** capture the unfiltered physical managed stack
from inside a resumed continuation and assert the boundary frames appear
in the expected leaf→root order:
- `RuntimeAsync_ResumeDispatchStack` (V2 single-yield)
- `StateMachineAsync_ResumeDispatchStack` (V1 single-yield)
- `StateMachineAsync_PoolingResumeDispatchStack` (V1 pooling →
standalone
`AsyncStateMachineDispatcher`)
- `StateMachineAsync_InlineCompletionClimb` (V1 inline completion, child
frames remain beneath the resuming parent)
- Frame identity is resolved via `DiagnosticMethodInfo` (stack-trace
metadata) rather than `StackFrame.GetMethod()` (reflection), so the
tests work on CoreCLR, Mono, and NativeAOT — the latter trims reflection
metadata but preserves stack-trace metadata (including names for
`[StackTraceHidden]` Ecma methods).
Tests are gated by runtime capability: V1 tests run on CoreCLR + Mono;
V2 tests run on CoreCLR (+ NativeAOT for the frame-capture test);
reflection-based name-contract tests are CoreCLR/Mono only.
## Risk / compatibility
- No change to async dispatch behavior. `[StackTraceHidden]` only
affects stack-trace *display*, and the newly-hidden V1
`InstrumentedMoveNext` frames are only present when the async profiler
is active.
- The env-var rename targets an unshipped diagnostic knob, so it is not
a breaking change.
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Aug 11, 2026

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@noahfalknoahfalknoahfalk approved these changes

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