src/hotspot/share/gc/shenandoah/shenandoahNMethod.cpp

rev 59811 : 8247670: Shenandoah: deadlock during class unloading OOME

*** 611,615 ****
--- 611,641 ----
    assert(ShenandoahConcurrentRoots::can_do_concurrent_class_unloading(),
           "Only for concurrent class unloading");
    _table->finish_iteration(_table_snapshot);
    CodeCache_lock->notify_all();
  }
+ 
+ ShenandoahAbortableNMethodLocker::ShenandoahAbortableNMethodLocker(ShenandoahReentrantLock* lock) :
+   _heap(ShenandoahHeap::heap()), _lock(lock), _aborted(false) {
+   while (!_aborted) {
+     // Try lock first. Because we really don't want to abort,
+     // which may result massive deopt. from nmethod entry barrier
+     if (_lock->try_lock()) {
+       break;
+     } else if (_heap->cancelled_gc()) {
+       _aborted = true;
+     } else {
+       // Spin a little. Since the lock is per-nmethod, we can expect the other
+       // thread to release the lock fair soon.
+       for (int i = 0; i < 4096; i ++) {
+         SpinPause();
+       }
+     }
+   }
+ }
+ 
+ ShenandoahAbortableNMethodLocker::~ShenandoahAbortableNMethodLocker() {
+   if (_lock != NULL && !_aborted) {
+     assert(_lock->owned_by_self(), "Must be owner");
+     _lock->unlock();
+   }
+ }