src/share/vm/memory/gcLocker.cpp

*** 26,36 ****
  #include "memory/gcLocker.inline.hpp"
  #include "memory/resourceArea.hpp"
  #include "memory/sharedHeap.hpp"
  
  volatile jint GC_locker::_jni_lock_count = 0;
- volatile jint GC_locker::_lock_count     = 0;
  volatile bool GC_locker::_needs_gc       = false;
  volatile bool GC_locker::_doing_gc       = false;
  
  #ifdef ASSERT
  volatile jint GC_locker::_debug_jni_lock_count = 0;
--- 26,35 ----
*** 100,110 ****
    // Block entering threads if we know at least one thread is in a
    // JNI critical region and we need a GC.
    // We check that at least one thread is in a critical region before
    // blocking because blocked threads are woken up by a thread exiting
    // a JNI critical region.
!   while ((needs_gc() && is_jni_active()) || _doing_gc) {
      JNICritical_lock->wait();
    }
    thread->enter_critical();
    _jni_lock_count++;
    increment_debug_jni_lock_count();
--- 99,109 ----
    // Block entering threads if we know at least one thread is in a
    // JNI critical region and we need a GC.
    // We check that at least one thread is in a critical region before
    // blocking because blocked threads are woken up by a thread exiting
    // a JNI critical region.
!   while (is_active_and_needs_gc() || _doing_gc) {
      JNICritical_lock->wait();
    }
    thread->enter_critical();
    _jni_lock_count++;
    increment_debug_jni_lock_count();
*** 114,130 ****
    assert(thread->in_last_critical(), "should be exiting critical region");
    MutexLocker mu(JNICritical_lock);
    _jni_lock_count--;
    decrement_debug_jni_lock_count();
    thread->exit_critical();
!   if (needs_gc() && !is_jni_active()) {
      // We're the last thread out. Cause a GC to occur.
-     // GC will also check is_active, so this check is not
-     // strictly needed. It's added here to make it clear that
-     // the GC will NOT be performed if any other caller
-     // of GC_locker::lock() still needs GC locked.
-     if (!is_active_internal()) {
        _doing_gc = true;
        {
          // Must give up the lock while at a safepoint
          MutexUnlocker munlock(JNICritical_lock);
          if (PrintJNIGCStalls && PrintGCDetails) {
--- 113,124 ----
    assert(thread->in_last_critical(), "should be exiting critical region");
    MutexLocker mu(JNICritical_lock);
    _jni_lock_count--;
    decrement_debug_jni_lock_count();
    thread->exit_critical();
!   if (needs_gc() && !is_active_internal()) {
      // We're the last thread out. Cause a GC to occur.
      _doing_gc = true;
      {
        // Must give up the lock while at a safepoint
        MutexUnlocker munlock(JNICritical_lock);
        if (PrintJNIGCStalls && PrintGCDetails) {
*** 133,144 ****
                                   gclog_or_tty->time_stamp().seconds(), Thread::current()->name(), _jni_lock_count);
          }
          Universe::heap()->collect(GCCause::_gc_locker);
        }
        _doing_gc = false;
-     }
- 
      _needs_gc = false;
      JNICritical_lock->notify_all();
    }
  }
  
--- 127,136 ----