src/share/vm/memory/gcLocker.cpp

@@ -26,11 +26,10 @@
 #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;

@@ -100,11 +99,11 @@
   // 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) {
+  while (is_active_and_needs_gc() || _doing_gc) {
     JNICritical_lock->wait();
   }
   thread->enter_critical();
   _jni_lock_count++;
   increment_debug_jni_lock_count();

@@ -114,17 +113,12 @@
   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()) {
+  if (needs_gc() && !is_active_internal()) {
     // 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) {

@@ -133,12 +127,10 @@
                                  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();
   }
 }