et2-java/Callbacks.cc at master · ElephantTracksProject/et2-java · GitHub

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#include"Callbacks.h"
#include"InstrumentBytecode.h"
#include"ETProxy_class.h"
#include"InstrumentFlag_class.h"
#include"ObjectSize.h"
#include<cassert>
#include<cstring>
#include<iostream>
#include<fstream>
#include<jnif.hpp>

usingnamespacestd;

voidJNICALLonMethodEntry(jvmtiEnv *jvmti, JNIEnv *jni, jthread th, jmethodID method)
{
unsignedchar *name;
// not safe, but I think no one has a 201 byte class name!
 jvmtiError error = jvmti->Allocate(200, &name);
assert(!error);

 error = jvmti->GetMethodName(method, (char**) &name, nullptr, nullptr);
assert(!error);

// do this until we get to main
if (string((char*) name) == "main") {

#ifdef DEBUG
 cerr << "Finally we got to main" << endl;
#endif

try {
 jclass etProxyClass = jni->FindClass("ETProxy");
 jclass runnableClass = jni->FindClass("ETProxy.ShutdownRunnable");
 jfieldID atMain = jni->GetStaticFieldID(etProxyClass, "atMain", "Z");
 jni->SetStaticBooleanField(etProxyClass, atMain, (jboolean) true);
 } catch (exception &e) {
 cerr << "Unable to load ETProxy and related classes." << endl;
 cerr << e.what() << endl;
assert(false);
 }

// reset callbacks
 jvmtiEventCallbacks callbacks;

 (void) memset(&callbacks, 0, sizeof(callbacks));

 callbacks.VMStart = &onVMStart;
 callbacks.VMInit = &onVMInit;

 callbacks.ClassFileLoadHook = &onClassFileLoad;
 callbacks.VMDeath = &flushBuffers;

 jvmtiError error = jvmti->SetEventCallbacks(&callbacks, (jint) sizeof(callbacks));
assert(!error);


 }

 error = jvmti->Deallocate(name);
assert(!error);
}

voidJNICALLonVMInit(jvmtiEnv *jvmti, JNIEnv *jni, jthread th)
{
 #ifdef DEBUG
 cerr << "JVM initialized" << endl;
 #endif
 isReady = true;
}

voidJNICALLonVMStart(jvmtiEnv *jvmti, JNIEnv *jni)
{
 #ifdef DEBUG
 cerr << "JVM started" << endl;
 #endif

 jni->DefineClass("InstrumentFlag", NULL, (jbyte *) InstrumentFlag_class, (jsize) InstrumentFlag_class_len);
 jclass etProxyClass = jni->DefineClass("ETProxy", NULL, (jbyte *) ETProxy_class, (jsize) ETProxy_class_len);

 JNINativeMethod jniMethod;

 jniMethod.name = (char *) "getObjectSize";
 jniMethod.signature = (char *) "(Ljava/lang/Object;)I";
 jniMethod.fnPtr = (void *) jniObjectSize;

 jint suc = jni->RegisterNatives(etProxyClass, &jniMethod, 1);
assert(suc == 0);
}

voidJNICALLonClassFileLoad(jvmtiEnv *jvmti,
 JNIEnv *jni,
 jclass class_being_redefined,
 jobject loader,
constchar *class_name,
 jobject protection_domain,
 jint class_data_len,
constunsignedchar *class_data,
 jint *new_class_data_len,
unsignedchar **new_class_data)
{
 #ifdef DEBUG
 cerr << "Loading class: " << string(class_name) << endl;
 cerr << "id " << classTable.mapOrFind(string(class_name)) << ": " << string(class_name) << endl;
 #endif

if (!isReady || string(class_name).find("java/util") == 0) { return; }

if (class_name == nullptr) {
// maybe should throw exception instead; don't yet know what exactly to do
return;
 }

if (string(class_name).find("sun") == 0) {
return;
 }

try {
#ifdef DEBUG
 cerr << "About to instrument: " << string(class_name) << endl;
#endif
instrumentClass(jvmti, jni, loader, (unsignedchar *) class_data, class_data_len,
 new_class_data_len, new_class_data);
#ifdef DEBUG
 cerr << "Instrumentation of " << string(class_name) << " successful" << endl;
#endif
 } catch (exception &e) {
// cerr << "Exception!: " << e.what() << endl;
throw;
 }
}

staticvoidflushMethodTable(MethodTable &methodTable, ofstream &methodDataF)
{
for (auto it = methodTable.begin(); it != methodTable.end(); ++it) {
long methodID = it->first;
 string className = (it->second).first;
 string methodName = (it->second).second;

 methodDataF << methodID << ", " << className << ", " << methodName << endl;
 }
}


voidJNICALLflushBuffers(jvmtiEnv *jvmti, JNIEnv *jni)
{
// Flush the method call timestamp buffer first
 jclass proxyClass = jni->FindClass("ETProxy");
 jmethodID flushBuffer = jni->GetStaticMethodID(proxyClass, "flushBuffer", "()V");
 jni->CallStaticVoidMethod(proxyClass, flushBuffer);

 ofstream methodDataF, classDataF, fieldDataF;
 methodDataF.open("methods.list");
 classDataF.open("classes.list");
 fieldDataF.open("fields.list");

// Then flush the rest of the timestamp table
flushMethodTable(methodTable, methodDataF);
 classTable.dumpTable(classDataF);
 fieldTable.dumpTable(fieldDataF);

 methodDataF.close();
 classDataF.close();
 fieldDataF.close();
}