C++ (Cpp) JavaThread::set_external_suspend Examples

Example #1

File: fprofiler.cpp Project: 4T-Shirt/OpenJDK-Research

void FlatProfiler::record_thread_ticks() {

  int maxthreads, suspendedthreadcount;
  JavaThread** threadsList;
  bool interval_expired = false;

  if (ProfileIntervals &&
      (FlatProfiler::received_ticks >= interval_ticks_previous + ProfileIntervalsTicks)) {
    interval_expired = true;
    interval_ticks_previous = FlatProfiler::received_ticks;
  }

  // Try not to wait for the Threads_lock
  if (Threads_lock->try_lock()) {
    {  // Threads_lock scope
      maxthreads = Threads::number_of_threads();
      threadsList = NEW_C_HEAP_ARRAY(JavaThread *, maxthreads, mtInternal);
      suspendedthreadcount = 0;
      for (JavaThread* tp = Threads::first(); tp != NULL; tp = tp->next()) {
        if (tp->is_Compiler_thread()) {
          // Only record ticks for active compiler threads
          CompilerThread* cthread = (CompilerThread*)tp;
          if (cthread->task() != NULL) {
            // The compiler is active.  If we need to access any of the fields
            // of the compiler task we should suspend the CompilerThread first.
            FlatProfiler::compiler_ticks += 1;
            continue;
          }
        }

        // First externally suspend all threads by marking each for
        // external suspension - so it will stop at its next transition
        // Then do a safepoint
        ThreadProfiler* pp = tp->get_thread_profiler();
        if (pp != NULL && pp->engaged) {
          MutexLockerEx ml(tp->SR_lock(), Mutex::_no_safepoint_check_flag);
          if (!tp->is_external_suspend() && !tp->is_exiting()) {
            tp->set_external_suspend();
            threadsList[suspendedthreadcount++] = tp;
          }
        }
      }
      Threads_lock->unlock();
    }