src/share/vm/runtime/advancedThresholdPolicy.cpp

rev 6096 : 8023461: Thread holding lock at safepoint that vm can block on: MethodCompileQueue_lock
Reviewed-by: ?

*** 72,86 ****
    set_start_time(os::javaTimeMillis());
  }
  
  // update_rate() is called from select_task() while holding a compile queue lock.
  void AdvancedThresholdPolicy::update_rate(jlong t, Method* m) {
!   JavaThread* THREAD = JavaThread::current();
    if (is_old(m)) {
      // We don't remove old methods from the queue,
      // so we can just zero the rate.
!     m->set_rate(0, THREAD);
      return;
    }
  
    // We don't update the rate if we've just came out of a safepoint.
    // delta_s is the time since last safepoint in milliseconds.
--- 72,89 ----
    set_start_time(os::javaTimeMillis());
  }
  
  // update_rate() is called from select_task() while holding a compile queue lock.
  void AdvancedThresholdPolicy::update_rate(jlong t, Method* m) {
!   // Skip update if counters are absent.
!   // Can't allocate them since we are holding compile queue lock.
!   if (m->method_counters() == NULL)  return;
! 
    if (is_old(m)) {
      // We don't remove old methods from the queue,
      // so we can just zero the rate.
!     m->set_rate(0);
      return;
    }
  
    // We don't update the rate if we've just came out of a safepoint.
    // delta_s is the time since last safepoint in milliseconds.
*** 92,108 ****
  
    // We should be running for at least 1ms.
    if (delta_s >= TieredRateUpdateMinTime) {
      // And we must've taken the previous point at least 1ms before.
      if (delta_t >= TieredRateUpdateMinTime && delta_e > 0) {
!       m->set_prev_time(t, THREAD);
!       m->set_prev_event_count(event_count, THREAD);
!       m->set_rate((float)delta_e / (float)delta_t, THREAD); // Rate is events per millisecond
!     } else
        if (delta_t > TieredRateUpdateMaxTime && delta_e == 0) {
          // If nothing happened for 25ms, zero the rate. Don't modify prev values.
!         m->set_rate(0, THREAD);
        }
    }
  }
  
  // Check if this method has been stale from a given number of milliseconds.
--- 95,112 ----
  
    // We should be running for at least 1ms.
    if (delta_s >= TieredRateUpdateMinTime) {
      // And we must've taken the previous point at least 1ms before.
      if (delta_t >= TieredRateUpdateMinTime && delta_e > 0) {
!       m->set_prev_time(t);
!       m->set_prev_event_count(event_count);
!       m->set_rate((float)delta_e / (float)delta_t); // Rate is events per millisecond
!     } else {
        if (delta_t > TieredRateUpdateMaxTime && delta_e == 0) {
          // If nothing happened for 25ms, zero the rate. Don't modify prev values.
!         m->set_rate(0);
!       }
      }
    }
  }
  
  // Check if this method has been stale from a given number of milliseconds.
*** 161,171 ****
    jlong t = os::javaTimeMillis();
    // Iterate through the queue and find a method with a maximum rate.
    for (CompileTask* task = compile_queue->first(); task != NULL;) {
      CompileTask* next_task = task->next();
      Method* method = task->method();
-     MethodData* mdo = method->method_data();
      update_rate(t, method);
      if (max_task == NULL) {
        max_task = task;
        max_method = method;
      } else {
--- 165,174 ----