Method getJavaTraceAsync

src/profiler.cpp:340–375

}

int Profiler::getJavaTraceAsync(void* ucontext, ASGCT_CallFrame* frames, int max_depth) {
    // Workaround for JDK-8132510: it's not safe to call GetEnv() inside a signal handler
    // since JDK 9, so we do it only for threads already registered in ThreadLocalStorage
    VMThread* vm_thread = VMThread::current();
    if (vm_thread == NULL) {
        return 0;
    }

    JNIEnv* jni = vm_thread->jni();
    if (_features.jnienv) {
        // jnienv feature is only used in tests to validate JNIEnv discovery through VMStructs.
        // Normally, we avoid calling VM::jni() inside a signal handler as it may deadlock.
        assert(jni == VM::jni());
    }
    if (jni == NULL) {
        // Not a Java thread
        return 0;
    }

    JitWriteProtection jit(false);
    ASGCT_CallTrace trace = {jni, 0, frames};
    VM::_asyncGetCallTrace(&trace, max_depth, ucontext);

    if (trace.num_frames > 0) {
        return trace.num_frames;
    }

    const char* err_string = asgctError(trace.num_frames);
    if (err_string == NULL) {
        // No Java stack, because thread is not in Java context
        return 0;
    }

    atomicInc(_failures[-trace.num_frames]);
    return makeFrame(frames, BCI_ERROR, err_string);
}

int Profiler::getJavaTraceJvmti(jvmtiFrameInfo* jvmti_frames, ASGCT_CallFrame* frames, int start_depth, int max_depth) {
    int num_frames = 0;