Example #1
0
void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) {

// This is if'd out because we no longer use thread suspension.
// However if someone wanted to backport this to a 5.0 jvm then this
// code would be important.
#if 0
  if (SafepointSynchronize::is_synchronizing()) {
    // The safepoint mechanism is trying to synchronize all the threads.
    // Since this can involve thread suspension, it is not safe for us
    // to be here. We can reduce the deadlock risk window by quickly
    // returning to the SIGPROF handler. However, it is still possible
    // for VMThread to catch us here or in the SIGPROF handler. If we
    // are suspended while holding a resource and another thread blocks
    // on that resource in the SIGPROF handler, then we will have a
    // three-thread deadlock (VMThread, this thread, the other thread).
    trace->num_frames = ticks_safepoint; // -10
    return;
  }
#endif

  JavaThread* thread;

  if (trace->env_id == NULL ||
    (thread = JavaThread::thread_from_jni_environment(trace->env_id)) == NULL ||
    thread->is_exiting()) {

    // bad env_id, thread has exited or thread is exiting
    trace->num_frames = ticks_thread_exit; // -8
    return;
  }

  if (thread->in_deopt_handler()) {
    // thread is in the deoptimization handler so return no frames
    trace->num_frames = ticks_deopt; // -9
    return;
  }

  assert(JavaThread::current() == thread,
         "AsyncGetCallTrace must be called by the current interrupted thread");

  if (!JvmtiExport::should_post_class_load()) {
    trace->num_frames = ticks_no_class_load; // -1
    return;
  }

  if (Universe::heap()->is_gc_active()) {
    trace->num_frames = ticks_GC_active; // -2
    return;
  }

  switch (thread->thread_state()) {
  case _thread_new:
  case _thread_uninitialized:
  case _thread_new_trans:
    // We found the thread on the threads list above, but it is too
    // young to be useful so return that there are no Java frames.
    trace->num_frames = 0;
    break;
  case _thread_in_native:
  case _thread_in_native_trans:
  case _thread_blocked:
  case _thread_blocked_trans:
  case _thread_in_vm:
  case _thread_in_vm_trans:
    {
      frame fr;

      // param isInJava == false - indicate we aren't in Java code
      if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, false)) {
        trace->num_frames = ticks_unknown_not_Java;  // -3 unknown frame
      } else {
        if (!thread->has_last_Java_frame()) {
          trace->num_frames = 0; // No Java frames
        } else {
          trace->num_frames = ticks_not_walkable_not_Java;    // -4 non walkable frame by default
          forte_fill_call_trace_given_top(thread, trace, depth, fr);

          // This assert would seem to be valid but it is not.
          // It would be valid if we weren't possibly racing a gc
          // thread. A gc thread can make a valid interpreted frame
          // look invalid. It's a small window but it does happen.
          // The assert is left here commented out as a reminder.
          // assert(trace->num_frames != ticks_not_walkable_not_Java, "should always be walkable");

        }
      }
    }
    break;
  case _thread_in_Java:
  case _thread_in_Java_trans:
    {
      frame fr;

      // param isInJava == true - indicate we are in Java code
      if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, true)) {
        trace->num_frames = ticks_unknown_Java;  // -5 unknown frame
      } else {
        trace->num_frames = ticks_not_walkable_Java;  // -6, non walkable frame by default
        forte_fill_call_trace_given_top(thread, trace, depth, fr);
      }
    }
    break;
  default:
    // Unknown thread state
    trace->num_frames = ticks_unknown_state; // -7
    break;
  }
}
Example #2
0
JNIEXPORT
void AsyncGetCallTrace(ASGCT_CallTrace *trace, jint depth, void* ucontext) {
  JavaThread* thread;

  if (trace->env_id == NULL ||
    (thread = JavaThread::thread_from_jni_environment(trace->env_id)) == NULL ||
    thread->is_exiting()) {

    // bad env_id, thread has exited or thread is exiting
    trace->num_frames = ticks_thread_exit; // -8
    return;
  }

  if (thread->in_deopt_handler()) {
    // thread is in the deoptimization handler so return no frames
    trace->num_frames = ticks_deopt; // -9
    return;
  }

  assert(JavaThread::current() == thread,
         "AsyncGetCallTrace must be called by the current interrupted thread");

  if (!JvmtiExport::should_post_class_load()) {
    trace->num_frames = ticks_no_class_load; // -1
    return;
  }

  if (Universe::heap()->is_gc_active()) {
    trace->num_frames = ticks_GC_active; // -2
    return;
  }

  switch (thread->thread_state()) {
  case _thread_new:
  case _thread_uninitialized:
  case _thread_new_trans:
    // We found the thread on the threads list above, but it is too
    // young to be useful so return that there are no Java frames.
    trace->num_frames = 0;
    break;
  case _thread_in_native:
  case _thread_in_native_trans:
  case _thread_blocked:
  case _thread_blocked_trans:
  case _thread_in_vm:
  case _thread_in_vm_trans:
    {
      frame fr;

      // param isInJava == false - indicate we aren't in Java code
      if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, false)) {
        trace->num_frames = ticks_unknown_not_Java;  // -3 unknown frame
      } else {
        if (!thread->has_last_Java_frame()) {
          trace->num_frames = 0; // No Java frames
        } else {
          trace->num_frames = ticks_not_walkable_not_Java;    // -4 non walkable frame by default
          forte_fill_call_trace_given_top(thread, trace, depth, fr);

          // This assert would seem to be valid but it is not.
          // It would be valid if we weren't possibly racing a gc
          // thread. A gc thread can make a valid interpreted frame
          // look invalid. It's a small window but it does happen.
          // The assert is left here commented out as a reminder.
          // assert(trace->num_frames != ticks_not_walkable_not_Java, "should always be walkable");

        }
      }
    }
    break;
  case _thread_in_Java:
  case _thread_in_Java_trans:
    {
      frame fr;

      // param isInJava == true - indicate we are in Java code
      if (!thread->pd_get_top_frame_for_signal_handler(&fr, ucontext, true)) {
        trace->num_frames = ticks_unknown_Java;  // -5 unknown frame
      } else {
        trace->num_frames = ticks_not_walkable_Java;  // -6, non walkable frame by default
        forte_fill_call_trace_given_top(thread, trace, depth, fr);
      }
    }
    break;
  default:
    // Unknown thread state
    trace->num_frames = ticks_unknown_state; // -7
    break;
  }
}