src/share/vm/gc/shared/gcLocker.cpp

*** 24,33 ****
--- 24,34 ----
  
  #include "precompiled.hpp"
  #include "gc/shared/collectedHeap.hpp"
  #include "gc/shared/gcLocker.inline.hpp"
  #include "memory/resourceArea.hpp"
+ #include "logging/log.hpp"
  #include "runtime/atomic.inline.hpp"
  #include "runtime/thread.inline.hpp"
  
  volatile jint GC_locker::_jni_lock_count = 0;
  volatile bool GC_locker::_needs_gc       = false;
*** 71,105 ****
    assert(_debug_jni_lock_count > 0, "bad value");
    Atomic::dec(&_debug_jni_lock_count);
  }
  #endif
  
  bool GC_locker::check_active_before_gc() {
    assert(SafepointSynchronize::is_at_safepoint(), "only read at safepoint");
    if (is_active() && !_needs_gc) {
      verify_critical_count();
      _needs_gc = true;
!     if (PrintJNIGCStalls && PrintGCDetails) {
!       ResourceMark rm; // JavaThread::name() allocates to convert to UTF8
!       gclog_or_tty->print_cr("%.3f: Setting _needs_gc. Thread \"%s\" %d locked.",
!                              gclog_or_tty->time_stamp().seconds(), Thread::current()->name(), _jni_lock_count);
!     }
! 
    }
    return is_active();
  }
  
  void GC_locker::stall_until_clear() {
    assert(!JavaThread::current()->in_critical(), "Would deadlock");
    MutexLocker   ml(JNICritical_lock);
  
    if (needs_gc()) {
!     if (PrintJNIGCStalls && PrintGCDetails) {
!       ResourceMark rm; // JavaThread::name() allocates to convert to UTF8
!       gclog_or_tty->print_cr("%.3f: Allocation failed. Thread \"%s\" is stalled by JNI critical section, %d locked.",
!                              gclog_or_tty->time_stamp().seconds(), Thread::current()->name(), _jni_lock_count);
!     }
    }
  
    // Wait for _needs_gc  to be cleared
    while (needs_gc()) {
      JNICritical_lock->wait();
--- 72,105 ----
    assert(_debug_jni_lock_count > 0, "bad value");
    Atomic::dec(&_debug_jni_lock_count);
  }
  #endif
  
+ void GC_locker::log_debug_jni(const char* msg) {
+   LogHandle(gc, jni) log;
+   if (log.is_debug()) {
+     ResourceMark rm; // JavaThread::name() allocates to convert to UTF8
+     log.debug("%s Thread \"%s\" %d locked.", msg, Thread::current()->name(), _jni_lock_count);
+   }
+ }
+ 
  bool GC_locker::check_active_before_gc() {
    assert(SafepointSynchronize::is_at_safepoint(), "only read at safepoint");
    if (is_active() && !_needs_gc) {
      verify_critical_count();
      _needs_gc = true;
!     log_debug_jni("Setting _needs_gc.");
    }
    return is_active();
  }
  
  void GC_locker::stall_until_clear() {
    assert(!JavaThread::current()->in_critical(), "Would deadlock");
    MutexLocker   ml(JNICritical_lock);
  
    if (needs_gc()) {
!     log_debug_jni("Allocation failed. Thread stalled by JNI critical section.");
    }
  
    // Wait for _needs_gc  to be cleared
    while (needs_gc()) {
      JNICritical_lock->wait();
*** 132,146 ****
      // 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) {
!         ResourceMark rm; // JavaThread::name() allocates to convert to UTF8
!         gclog_or_tty->print_cr("%.3f: Thread \"%s\" is performing GC after exiting critical section, %d locked",
!             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();
--- 132,142 ----
      // 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);
!       log_debug_jni("Performing GC after exiting critical section.");
        Universe::heap()->collect(GCCause::_gc_locker);
      }
      _doing_gc = false;
      _needs_gc = false;
      JNICritical_lock->notify_all();