# HG changeset patch
# User coleenp
# Date 1418351683 18000
# Node ID 322d55d167be0c858fe2cf7a585adbea0a7f17a1
# Parent  a4075664328dd1fb2e408667dca278a716480600
8047290: Make Mutex::_no_safepoint_check_flag locks verify that this lock never checks for safepoint
Summary: Ensure consistent safepoint checking in Mutex/Monitor locking methods.
Reviewed-by: dholmes, dcubed, coleenp
Contributed-by: max.ockner@oracle.com

diff -r a4075664328d -r 322d55d167be hotspot/src/os/aix/vm/osThread_aix.cpp
--- a/hotspot/src/os/aix/vm/osThread_aix.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/os/aix/vm/osThread_aix.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2012, 2013 SAP AG. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
@@ -45,7 +45,8 @@
 
   sigemptyset(&_caller_sigmask);
 
-  _startThread_lock = new Monitor(Mutex::event, "startThread_lock", true);
+  _startThread_lock = new Monitor(Mutex::event, "startThread_lock", true,
+                                  Monitor::_safepoint_check_never);
   assert(_startThread_lock !=NULL, "check");
 }
 
diff -r a4075664328d -r 322d55d167be hotspot/src/os/bsd/vm/osThread_bsd.cpp
--- a/hotspot/src/os/bsd/vm/osThread_bsd.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/os/bsd/vm/osThread_bsd.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -43,7 +43,8 @@
 
   sigemptyset(&_caller_sigmask);
 
-  _startThread_lock = new Monitor(Mutex::event, "startThread_lock", true);
+  _startThread_lock = new Monitor(Mutex::event, "startThread_lock", true,
+                                  Monitor::_safepoint_check_never);
   assert(_startThread_lock !=NULL, "check");
 }
 
diff -r a4075664328d -r 322d55d167be hotspot/src/os/linux/vm/osThread_linux.cpp
--- a/hotspot/src/os/linux/vm/osThread_linux.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/os/linux/vm/osThread_linux.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -39,7 +39,8 @@
 
   sigemptyset(&_caller_sigmask);
 
-  _startThread_lock = new Monitor(Mutex::event, "startThread_lock", true);
+  _startThread_lock = new Monitor(Mutex::event, "startThread_lock", true,
+                                  Monitor::_safepoint_check_never);
   assert(_startThread_lock !=NULL, "check");
 }
 
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/classfile/classLoaderData.cpp
--- a/hotspot/src/share/vm/classfile/classLoaderData.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/classfile/classLoaderData.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -81,7 +81,8 @@
   _metaspace(NULL), _unloading(false), _klasses(NULL),
   _claimed(0), _jmethod_ids(NULL), _handles(NULL), _deallocate_list(NULL),
   _next(NULL), _dependencies(dependencies),
-  _metaspace_lock(new Mutex(Monitor::leaf+1, "Metaspace allocation lock", true)) {
+  _metaspace_lock(new Mutex(Monitor::leaf+1, "Metaspace allocation lock", true,
+                            Monitor::_safepoint_check_never)) {
     // empty
 }
 
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -83,9 +83,11 @@
   // Note: this requires that CFLspace c'tors
   // are called serially in the order in which the locks are
   // are acquired in the program text. This is true today.
-  _freelistLock(_lockRank--, "CompactibleFreeListSpace._lock", true),
+  _freelistLock(_lockRank--, "CompactibleFreeListSpace._lock", true,
+                Monitor::_safepoint_check_sometimes),
   _parDictionaryAllocLock(Mutex::leaf - 1,  // == rank(ExpandHeap_lock) - 1
-                          "CompactibleFreeListSpace._dict_par_lock", true),
+                          "CompactibleFreeListSpace._dict_par_lock", true,
+                          Monitor::_safepoint_check_never),
   _rescan_task_size(CardTableModRefBS::card_size_in_words * BitsPerWord *
                     CMSRescanMultiple),
   _marking_task_size(CardTableModRefBS::card_size_in_words * BitsPerWord *
@@ -152,8 +154,7 @@
   // Initialize locks for parallel case.
   for (size_t i = IndexSetStart; i < IndexSetSize; i += IndexSetStride) {
     _indexedFreeListParLocks[i] = new Mutex(Mutex::leaf - 1, // == ExpandHeap_lock - 1
-                                            "a freelist par lock",
-                                            true);
+                                            "a freelist par lock", true, Mutex::_safepoint_check_sometimes);
     DEBUG_ONLY(
       _indexedFreeList[i].set_protecting_lock(_indexedFreeListParLocks[i]);
     )
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -479,7 +479,9 @@
   _restart_addr(NULL),
   _overflow_list(NULL),
   _stats(cmsGen),
-  _eden_chunk_lock(new Mutex(Mutex::leaf + 1, "CMS_eden_chunk_lock", true)),
+  _eden_chunk_lock(new Mutex(Mutex::leaf + 1, "CMS_eden_chunk_lock", true,
+                             //verify that this lock should be acquired with safepoint check.
+                             Monitor::_safepoint_check_sometimes)),
   _eden_chunk_array(NULL),     // may be set in ctor body
   _eden_chunk_capacity(0),     // -- ditto --
   _eden_chunk_index(0),        // -- ditto --
@@ -6031,7 +6033,8 @@
 CMSBitMap::CMSBitMap(int shifter, int mutex_rank, const char* mutex_name):
   _bm(),
   _shifter(shifter),
-  _lock(mutex_rank >= 0 ? new Mutex(mutex_rank, mutex_name, true) : NULL)
+  _lock(mutex_rank >= 0 ? new Mutex(mutex_rank, mutex_name, true,
+                                    Monitor::_safepoint_check_sometimes) : NULL)
 {
   _bmStartWord = 0;
   _bmWordSize  = 0;
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp
--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp	Thu Dec 11 21:34:43 2014 -0500
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -188,7 +188,8 @@
 
  public:
   CMSMarkStack():
-    _par_lock(Mutex::event, "CMSMarkStack._par_lock", true),
+    _par_lock(Mutex::event, "CMSMarkStack._par_lock", true,
+              Monitor::_safepoint_check_never),
     _hit_limit(0),
     _failed_double(0) {}
 
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp
--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -52,7 +52,8 @@
   // The 0th worker in notified by mutator threads and has a special monitor.
   // The last worker is used for young gen rset size sampling.
   if (worker_id > 0) {
-    _monitor = new Monitor(Mutex::nonleaf, "Refinement monitor", true);
+    _monitor = new Monitor(Mutex::nonleaf, "Refinement monitor", true,
+                           Monitor::_safepoint_check_never);
   } else {
     _monitor = DirtyCardQ_CBL_mon;
   }
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -4933,7 +4933,7 @@
   }
 };
 
-Monitor* G1CodeCacheUnloadingTask::_lock = new Monitor(Mutex::leaf, "Code Cache Unload lock");
+Monitor* G1CodeCacheUnloadingTask::_lock = new Monitor(Mutex::leaf, "Code Cache Unload lock", false, Monitor::_safepoint_check_never);
 
 class G1KlassCleaningTask : public StackObj {
   BoolObjectClosure*                      _is_alive;
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp
--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -840,7 +840,7 @@
 HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa,
                                    HeapRegion* hr)
   : _bosa(bosa),
-    _m(Mutex::leaf, FormatBuffer<128>("HeapRegionRemSet lock #%u", hr->hrm_index()), true),
+    _m(Mutex::leaf, FormatBuffer<128>("HeapRegionRemSet lock #%u", hr->hrm_index()), true, Monitor::_safepoint_check_never),
     _code_roots(), _other_regions(hr, &_m), _iter_state(Unclaimed), _iter_claimed(0) {
   reset_for_par_iteration();
 }
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/gc_implementation/parallelScavenge/gcTaskManager.cpp
--- a/hotspot/src/share/vm/gc_implementation/parallelScavenge/gcTaskManager.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/gc_implementation/parallelScavenge/gcTaskManager.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -400,7 +400,8 @@
   assert(workers() != 0, "no workers");
   _monitor = new Monitor(Mutex::barrier,                // rank
                          "GCTaskManager monitor",       // name
-                         Mutex::_allow_vm_block_flag);  // allow_vm_block
+                         Mutex::_allow_vm_block_flag,   // allow_vm_block
+                         Monitor::_safepoint_check_never);
   // The queue for the GCTaskManager must be a CHeapObj.
   GCTaskQueue* unsynchronized_queue = GCTaskQueue::create_on_c_heap();
   _queue = SynchronizedGCTaskQueue::create(unsynchronized_queue, lock());
@@ -1125,7 +1126,8 @@
     } else {
       result = new Monitor(Mutex::barrier,                  // rank
                            "MonitorSupply monitor",         // name
-                           Mutex::_allow_vm_block_flag);    // allow_vm_block
+                           Mutex::_allow_vm_block_flag,     // allow_vm_block
+                           Monitor::_safepoint_check_never);
     }
     guarantee(result != NULL, "shouldn't return NULL");
     assert(!result->is_locked(), "shouldn't be locked");
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/gc_implementation/shared/concurrentGCThread.cpp
--- a/hotspot/src/share/vm/gc_implementation/shared/concurrentGCThread.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/gc_implementation/shared/concurrentGCThread.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -88,7 +88,8 @@
 
 SurrogateLockerThread::SurrogateLockerThread() :
   JavaThread(&_sltLoop),
-  _monitor(Mutex::nonleaf, "SLTMonitor"),
+  _monitor(Mutex::nonleaf, "SLTMonitor", false,
+           Monitor::_safepoint_check_sometimes),
   _buffer(empty)
 {}
 
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/memory/metaspace.cpp
--- a/hotspot/src/share/vm/memory/metaspace.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/memory/metaspace.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -792,7 +792,8 @@
 Mutex* const SpaceManager::_expand_lock =
   new Mutex(SpaceManager::_expand_lock_rank,
             SpaceManager::_expand_lock_name,
-            Mutex::_allow_vm_block_flag);
+            Mutex::_allow_vm_block_flag,
+            Monitor::_safepoint_check_never);
 
 void VirtualSpaceNode::inc_container_count() {
   assert_lock_strong(SpaceManager::expand_lock());
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/memory/sharedHeap.cpp
--- a/hotspot/src/share/vm/memory/sharedHeap.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/memory/sharedHeap.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -152,7 +152,7 @@
   }
 }
 
-Monitor* SharedHeap::StrongRootsScope::_lock = new Monitor(Mutex::leaf, "StrongRootsScope lock", false);
+Monitor* SharedHeap::StrongRootsScope::_lock = new Monitor(Mutex::leaf, "StrongRootsScope lock", false, Monitor::_safepoint_check_never);
 
 void SharedHeap::StrongRootsScope::mark_worker_done_with_threads(uint n_workers) {
   // The Thread work barrier is only needed by G1 Class Unloading.
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/prims/whitebox.cpp
--- a/hotspot/src/share/vm/prims/whitebox.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/prims/whitebox.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -1078,6 +1078,14 @@
   return (jlong) MetaspaceGC::capacity_until_GC();
 WB_END
 
+WB_ENTRY(void, WB_AssertMatchingSafepointCalls(JNIEnv* env, jobject o, jboolean mutexSafepointValue, jboolean attemptedNoSafepointValue))
+  Monitor::SafepointCheckRequired sfpt_check_required = mutexSafepointValue ?
+                                           Monitor::_safepoint_check_always :
+                                           Monitor::_safepoint_check_never;
+  MutexLockerEx ml(new Mutex(Mutex::leaf, "SFPT_Test_lock", true, sfpt_check_required),
+                   attemptedNoSafepointValue == JNI_TRUE);
+WB_END
+
 //Some convenience methods to deal with objects from java
 int WhiteBox::offset_for_field(const char* field_name, oop object,
     Symbol* signature_symbol) {
@@ -1274,6 +1282,7 @@
   {CC"getCodeBlob",        CC"(J)[Ljava/lang/Object;",(void*)&WB_GetCodeBlob        },
   {CC"getThreadStackSize", CC"()J",                   (void*)&WB_GetThreadStackSize },
   {CC"getThreadRemainingStackSize", CC"()J",          (void*)&WB_GetThreadRemainingStackSize },
+  {CC"assertMatchingSafepointCalls", CC"(ZZ)V",       (void*)&WB_AssertMatchingSafepointCalls },
 };
 
 #undef CC
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/runtime/mutex.cpp
--- a/hotspot/src/share/vm/runtime/mutex.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/runtime/mutex.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -895,6 +895,11 @@
 // of Mutex-Monitor and instead directly address the underlying design flaw.
 
 void Monitor::lock(Thread * Self) {
+  // Ensure that the Monitor requires/allows safepoint checks.
+  assert(_safepoint_check_required != Monitor::_safepoint_check_never,
+         err_msg("This lock should never have a safepoint check: %s",
+                 name()));
+
 #ifdef CHECK_UNHANDLED_OOPS
   // Clear unhandled oops so we get a crash right away.  Only clear for non-vm
   // or GC threads.
@@ -953,6 +958,10 @@
 // thread state set to be in VM, the safepoint synchronization code will deadlock!
 
 void Monitor::lock_without_safepoint_check(Thread * Self) {
+  // Ensure that the Monitor does not require or allow safepoint checks.
+  assert(_safepoint_check_required != Monitor::_safepoint_check_always,
+         err_msg("This lock should always have a safepoint check: %s",
+                 name()));
   assert(_owner != Self, "invariant");
   ILock(Self);
   assert(_owner == NULL, "invariant");
@@ -1082,6 +1091,12 @@
 
 bool Monitor::wait(bool no_safepoint_check, long timeout,
                    bool as_suspend_equivalent) {
+  // Make sure safepoint checking is used properly.
+  assert(!(_safepoint_check_required == Monitor::_safepoint_check_never && no_safepoint_check == false),
+         err_msg("This lock should never have a safepoint check: %s", name()));
+  assert(!(_safepoint_check_required == Monitor::_safepoint_check_always && no_safepoint_check == true),
+         err_msg("This lock should always have a safepoint check: %s", name()));
+
   Thread * const Self = Thread::current();
   assert(_owner == Self, "invariant");
   assert(ILocked(), "invariant");
@@ -1168,11 +1183,13 @@
 
 Monitor::Monitor() { ClearMonitor(this); }
 
-Monitor::Monitor(int Rank, const char * name, bool allow_vm_block) {
+Monitor::Monitor(int Rank, const char * name, bool allow_vm_block,
+                 SafepointCheckRequired safepoint_check_required) {
   ClearMonitor(this, name);
 #ifdef ASSERT
   _allow_vm_block  = allow_vm_block;
   _rank            = Rank;
+  NOT_PRODUCT(_safepoint_check_required = safepoint_check_required;)
 #endif
 }
 
@@ -1180,11 +1197,13 @@
   assert((UNS(_owner)|UNS(_LockWord.FullWord)|UNS(_EntryList)|UNS(_WaitSet)|UNS(_OnDeck)) == 0, "");
 }
 
-Mutex::Mutex(int Rank, const char * name, bool allow_vm_block) {
+Mutex::Mutex(int Rank, const char * name, bool allow_vm_block,
+             SafepointCheckRequired safepoint_check_required) {
   ClearMonitor((Monitor *) this, name);
 #ifdef ASSERT
   _allow_vm_block   = allow_vm_block;
   _rank             = Rank;
+  NOT_PRODUCT(_safepoint_check_required = safepoint_check_required;)
 #endif
 }
 
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/runtime/mutex.hpp
--- a/hotspot/src/share/vm/runtime/mutex.hpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/runtime/mutex.hpp	Thu Dec 11 21:34:43 2014 -0500
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -154,6 +154,24 @@
     _as_suspend_equivalent_flag = true
   };
 
+  // Locks can be acquired with or without safepoint check.
+  // Monitor::lock and Monitor::lock_without_safepoint_check
+  // checks these flags when acquiring a lock to ensure
+  // consistent checking for each lock.
+  // A few existing locks will sometimes have a safepoint check and
+  // sometimes not, but these locks are set up in such a way to avoid deadlocks.
+  enum SafepointCheckRequired {
+    _safepoint_check_never,       // Monitors with this value will cause errors
+                                  // when acquired with a safepoint check.
+    _safepoint_check_sometimes,   // Certain locks are called sometimes with and
+                                  // sometimes without safepoint checks. These
+                                  // locks will not produce errors when locked.
+    _safepoint_check_always       // Causes error if locked without a safepoint
+                                  // check.
+  };
+
+  NOT_PRODUCT(SafepointCheckRequired _safepoint_check_required;)
+
   enum WaitResults {
     CONDVAR_EVENT,         // Wait returned because of condition variable notification
     INTERRUPT_EVENT,       // Wait returned because waiting thread was interrupted
@@ -175,7 +193,8 @@
    Monitor() ;
 
  public:
-  Monitor(int rank, const char *name, bool allow_vm_block=false);
+  Monitor(int rank, const char *name, bool allow_vm_block = false,
+          SafepointCheckRequired safepoint_check_required = _safepoint_check_always);
   ~Monitor();
 
   // Wait until monitor is notified (or times out).
@@ -261,7 +280,8 @@
 
 class Mutex : public Monitor {      // degenerate Monitor
  public:
-   Mutex (int rank, const char *name, bool allow_vm_block=false);
+   Mutex(int rank, const char *name, bool allow_vm_block = false,
+         SafepointCheckRequired safepoint_check_required = _safepoint_check_always);
    ~Mutex () ;
  private:
    bool notify ()    { ShouldNotReachHere(); return false; }
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/runtime/mutexLocker.cpp
--- a/hotspot/src/share/vm/runtime/mutexLocker.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/runtime/mutexLocker.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -167,131 +167,133 @@
 }
 #endif
 
-#define def(var, type, pri, vm_block) {                           \
-  var = new type(Mutex::pri, #var, vm_block);                     \
-  assert(_num_mutex < MAX_NUM_MUTEX,                              \
-                    "increase MAX_NUM_MUTEX");                    \
-  _mutex_array[_num_mutex++] = var;                               \
+#define def(var, type, pri, vm_block, safepoint_check_allowed ) {      \
+  var = new type(Mutex::pri, #var, vm_block, safepoint_check_allowed); \
+  assert(_num_mutex < MAX_NUM_MUTEX, "increase MAX_NUM_MUTEX");        \
+  _mutex_array[_num_mutex] = var;                                      \
 }
 
 void mutex_init() {
-  def(tty_lock                     , Mutex  , event,       true ); // allow to lock in VM
+  def(tty_lock                     , Mutex  , event,       true,  Monitor::_safepoint_check_never);      // allow to lock in VM
 
-  def(CGC_lock                   , Monitor, special,     true ); // coordinate between fore- and background GC
-  def(STS_lock                   , Monitor, leaf,        true );
+  def(CGC_lock                     , Monitor, special,     true,  Monitor::_safepoint_check_never);      // coordinate between fore- and background GC
+  def(STS_lock                     , Monitor, leaf,        true,  Monitor::_safepoint_check_never);
+
   if (UseConcMarkSweepGC || UseG1GC) {
-    def(FullGCCount_lock           , Monitor, leaf,        true ); // in support of ExplicitGCInvokesConcurrent
+    def(FullGCCount_lock           , Monitor, leaf,        true,  Monitor::_safepoint_check_never);      // in support of ExplicitGCInvokesConcurrent
   }
   if (UseG1GC) {
-    def(CMark_lock                 , Monitor, nonleaf,     true ); // coordinate concurrent mark thread
-    def(CMRegionStack_lock         , Mutex,   leaf,        true );
-    def(SATB_Q_FL_lock             , Mutex  , special,     true );
-    def(SATB_Q_CBL_mon             , Monitor, nonleaf,     true );
-    def(Shared_SATB_Q_lock         , Mutex,   nonleaf,     true );
 
-    def(DirtyCardQ_FL_lock         , Mutex  , special,     true );
-    def(DirtyCardQ_CBL_mon         , Monitor, nonleaf,     true );
-    def(Shared_DirtyCardQ_lock     , Mutex,   nonleaf,     true );
+    def(CMark_lock                 , Monitor, nonleaf,     true,  Monitor::_safepoint_check_never);      // coordinate concurrent mark thread
+    def(CMRegionStack_lock         , Mutex,   leaf,        true,  Monitor::_safepoint_check_never);
+    def(SATB_Q_FL_lock             , Mutex  , special,     true,  Monitor::_safepoint_check_never);
+    def(SATB_Q_CBL_mon             , Monitor, nonleaf,     true,  Monitor::_safepoint_check_never);
+    def(Shared_SATB_Q_lock         , Mutex,   nonleaf,     true,  Monitor::_safepoint_check_never);
+
+    def(DirtyCardQ_FL_lock         , Mutex  , special,     true,  Monitor::_safepoint_check_never);
+    def(DirtyCardQ_CBL_mon         , Monitor, nonleaf,     true,  Monitor::_safepoint_check_never);
+    def(Shared_DirtyCardQ_lock     , Mutex,   nonleaf,     true,  Monitor::_safepoint_check_never);
 
-    def(FreeList_lock              , Mutex,   leaf     ,   true );
-    def(SecondaryFreeList_lock     , Monitor, leaf     ,   true );
-    def(OldSets_lock               , Mutex  , leaf     ,   true );
-    def(RootRegionScan_lock        , Monitor, leaf     ,   true );
-    def(MMUTracker_lock            , Mutex  , leaf     ,   true );
-    def(HotCardCache_lock          , Mutex  , special  ,   true );
-    def(EvacFailureStack_lock      , Mutex  , nonleaf  ,   true );
+    def(FreeList_lock              , Mutex,   leaf     ,   true,  Monitor::_safepoint_check_never);
+    def(SecondaryFreeList_lock     , Monitor, leaf     ,   true,  Monitor::_safepoint_check_never);
+    def(OldSets_lock               , Mutex  , leaf     ,   true,  Monitor::_safepoint_check_never);
+    def(RootRegionScan_lock        , Monitor, leaf     ,   true,  Monitor::_safepoint_check_never);
+    def(MMUTracker_lock            , Mutex  , leaf     ,   true,  Monitor::_safepoint_check_never);
+    def(HotCardCache_lock          , Mutex  , special  ,   true,  Monitor::_safepoint_check_never);
+    def(EvacFailureStack_lock      , Mutex  , nonleaf  ,   true,  Monitor::_safepoint_check_never);
 
-    def(StringDedupQueue_lock      , Monitor, leaf,        true );
-    def(StringDedupTable_lock      , Mutex  , leaf,        true );
+    def(StringDedupQueue_lock      , Monitor, leaf,        true,  Monitor::_safepoint_check_never);
+    def(StringDedupTable_lock      , Mutex  , leaf,        true,  Monitor::_safepoint_check_never);
   }
-  def(ParGCRareEvent_lock          , Mutex  , leaf     ,   true );
-  def(DerivedPointerTableGC_lock   , Mutex,   leaf,        true );
-  def(CodeCache_lock               , Monitor, special,     true );
-  def(Interrupt_lock               , Monitor, special,     true ); // used for interrupt processing
-  def(RawMonitor_lock              , Mutex,   special,     true );
-  def(OopMapCacheAlloc_lock        , Mutex,   leaf,        true ); // used for oop_map_cache allocation.
+  def(ParGCRareEvent_lock          , Mutex  , leaf     ,   true,  Monitor::_safepoint_check_sometimes);
+  def(DerivedPointerTableGC_lock   , Mutex,   leaf,        true,  Monitor::_safepoint_check_never);
+  def(CodeCache_lock               , Mutex  , special,     true,  Monitor::_safepoint_check_never);
+  def(Interrupt_lock               , Monitor, special,     true,  Monitor::_safepoint_check_never);      // used for interrupt processing
+  def(RawMonitor_lock              , Mutex,   special,     true,  Monitor::_safepoint_check_never);
+  def(OopMapCacheAlloc_lock        , Mutex,   leaf,        true,  Monitor::_safepoint_check_always);     // used for oop_map_cache allocation.
 
-  def(Patching_lock                , Mutex  , special,     true ); // used for safepointing and code patching.
-  def(ObjAllocPost_lock            , Monitor, special,     false);
-  def(Service_lock                 , Monitor, special,     true ); // used for service thread operations
-  def(JmethodIdCreation_lock       , Mutex  , leaf,        true ); // used for creating jmethodIDs.
+  def(Patching_lock                , Mutex  , special,     true,  Monitor::_safepoint_check_never);      // used for safepointing and code patching.
+  def(ObjAllocPost_lock            , Monitor, special,     false, Monitor::_safepoint_check_never);
+  def(Service_lock                 , Monitor, special,     true,  Monitor::_safepoint_check_never);      // used for service thread operations
+  def(JmethodIdCreation_lock       , Mutex  , leaf,        true,  Monitor::_safepoint_check_always);     // used for creating jmethodIDs.
 
-  def(SystemDictionary_lock        , Monitor, leaf,        true ); // lookups done by VM thread
-  def(PackageTable_lock            , Mutex  , leaf,        false);
-  def(InlineCacheBuffer_lock       , Mutex  , leaf,        true );
-  def(VMStatistic_lock             , Mutex  , leaf,        false);
-  def(ExpandHeap_lock              , Mutex  , leaf,        true ); // Used during compilation by VM thread
-  def(JNIHandleBlockFreeList_lock  , Mutex  , leaf,        true ); // handles are used by VM thread
-  def(SignatureHandlerLibrary_lock , Mutex  , leaf,        false);
-  def(SymbolTable_lock             , Mutex  , leaf+2,      true );
-  def(StringTable_lock             , Mutex  , leaf,        true );
-  def(ProfilePrint_lock            , Mutex  , leaf,        false); // serial profile printing
-  def(ExceptionCache_lock          , Mutex  , leaf,        false); // serial profile printing
-  def(OsrList_lock                 , Mutex  , leaf,        true );
-  def(Debug1_lock                  , Mutex  , leaf,        true );
+  def(SystemDictionary_lock        , Monitor, leaf,        true,  Monitor::_safepoint_check_always);     // lookups done by VM thread
+  def(PackageTable_lock            , Mutex  , leaf,        false, Monitor::_safepoint_check_always);
+  def(InlineCacheBuffer_lock       , Mutex  , leaf,        true,  Monitor::_safepoint_check_always);
+  def(VMStatistic_lock             , Mutex  , leaf,        false, Monitor::_safepoint_check_always);
+  def(ExpandHeap_lock              , Mutex  , leaf,        true,  Monitor::_safepoint_check_always);     // Used during compilation by VM thread
+  def(JNIHandleBlockFreeList_lock  , Mutex  , leaf,        true,  Monitor::_safepoint_check_never);      // handles are used by VM thread
+  def(SignatureHandlerLibrary_lock , Mutex  , leaf,        false, Monitor::_safepoint_check_always);
+  def(SymbolTable_lock             , Mutex  , leaf+2,      true,  Monitor::_safepoint_check_always);
+  def(StringTable_lock             , Mutex  , leaf,        true,  Monitor::_safepoint_check_always);
+  def(ProfilePrint_lock            , Mutex  , leaf,        false, Monitor::_safepoint_check_always);     // serial profile printing
+  def(ExceptionCache_lock          , Mutex  , leaf,        false, Monitor::_safepoint_check_always);     // serial profile printing
+  def(OsrList_lock                 , Mutex  , leaf,        true,  Monitor::_safepoint_check_never);
+  def(Debug1_lock                  , Mutex  , leaf,        true,  Monitor::_safepoint_check_never);
 #ifndef PRODUCT
-  def(FullGCALot_lock              , Mutex  , leaf,        false); // a lock to make FullGCALot MT safe
+  def(FullGCALot_lock              , Mutex  , leaf,        false, Monitor::_safepoint_check_always);     // a lock to make FullGCALot MT safe
 #endif
-  def(BeforeExit_lock              , Monitor, leaf,        true );
-  def(PerfDataMemAlloc_lock        , Mutex  , leaf,        true ); // used for allocating PerfData memory for performance data
-  def(PerfDataManager_lock         , Mutex  , leaf,        true ); // used for synchronized access to PerfDataManager resources
+  def(BeforeExit_lock              , Monitor, leaf,        true,  Monitor::_safepoint_check_always);
+  def(PerfDataMemAlloc_lock        , Mutex  , leaf,        true,  Monitor::_safepoint_check_always);     // used for allocating PerfData memory for performance data
+  def(PerfDataManager_lock         , Mutex  , leaf,        true,  Monitor::_safepoint_check_always);     // used for synchronized access to PerfDataManager resources
 
   // CMS_modUnionTable_lock                   leaf
-  // CMS_bitMap_lock                          leaf + 1
-  // CMS_freeList_lock                        leaf + 2
+  // CMS_bitMap_lock                          leaf 1
+  // CMS_freeList_lock                        leaf 2
 
-  def(Safepoint_lock               , Monitor, safepoint,   true ); // locks SnippetCache_lock/Threads_lock
+  def(Safepoint_lock               , Monitor, safepoint,   true,  Monitor::_safepoint_check_sometimes);  // locks SnippetCache_lock/Threads_lock
 
-  def(Threads_lock                 , Monitor, barrier,     true );
+  def(Threads_lock                 , Monitor, barrier,     true,  Monitor::_safepoint_check_sometimes);
 
-  def(VMOperationQueue_lock        , Monitor, nonleaf,     true ); // VM_thread allowed to block on these
-  def(VMOperationRequest_lock      , Monitor, nonleaf,     true );
-  def(RetData_lock                 , Mutex  , nonleaf,     false);
-  def(Terminator_lock              , Monitor, nonleaf,     true );
-  def(VtableStubs_lock             , Mutex  , nonleaf,     true );
-  def(Notify_lock                  , Monitor, nonleaf,     true );
-  def(JNIGlobalHandle_lock         , Mutex  , nonleaf,     true ); // locks JNIHandleBlockFreeList_lock
-  def(JNICritical_lock             , Monitor, nonleaf,     true ); // used for JNI critical regions
-  def(AdapterHandlerLibrary_lock   , Mutex  , nonleaf,     true);
+  def(VMOperationQueue_lock        , Monitor, nonleaf,     true,  Monitor::_safepoint_check_sometimes);  // VM_thread allowed to block on these
+  def(VMOperationRequest_lock      , Monitor, nonleaf,     true,  Monitor::_safepoint_check_sometimes);
+  def(RetData_lock                 , Mutex  , nonleaf,     false, Monitor::_safepoint_check_always);
+  def(Terminator_lock              , Monitor, nonleaf,     true,  Monitor::_safepoint_check_sometimes);
+  def(VtableStubs_lock             , Mutex  , nonleaf,     true,  Monitor::_safepoint_check_always);
+  def(Notify_lock                  , Monitor, nonleaf,     true,  Monitor::_safepoint_check_always);
+  def(JNIGlobalHandle_lock         , Mutex  , nonleaf,     true,  Monitor::_safepoint_check_always);     // locks JNIHandleBlockFreeList_lock
+  def(JNICritical_lock             , Monitor, nonleaf,     true,  Monitor::_safepoint_check_always);     // used for JNI critical regions
+  def(AdapterHandlerLibrary_lock   , Mutex  , nonleaf,     true,  Monitor::_safepoint_check_always);
   if (UseConcMarkSweepGC) {
-    def(SLT_lock                   , Monitor, nonleaf,     false );
-                    // used in CMS GC for locking PLL lock
+    def(SLT_lock                   , Monitor, nonleaf,     false, Monitor::_safepoint_check_never);      // used in CMS GC for locking PLL lock
   }
-  def(Heap_lock                    , Monitor, nonleaf+1,   false);
-  def(JfieldIdCreation_lock        , Mutex  , nonleaf+1,   true ); // jfieldID, Used in VM_Operation
-  def(MemberNameTable_lock         , Mutex  , nonleaf+1,   false); // Used to protect MemberNameTable
+
+  def(Heap_lock                    , Monitor, nonleaf+1,   false, Monitor::_safepoint_check_sometimes);
+  def(JfieldIdCreation_lock        , Mutex  , nonleaf+1,   true,  Monitor::_safepoint_check_always);     // jfieldID, Used in VM_Operation
+  def(MemberNameTable_lock         , Mutex  , nonleaf+1,   false, Monitor::_safepoint_check_always);     // Used to protect MemberNameTable
 
-  def(CompiledIC_lock              , Mutex  , nonleaf+2,   false); // locks VtableStubs_lock, InlineCacheBuffer_lock
-  def(CompileTaskAlloc_lock        , Mutex  , nonleaf+2,   true );
-  def(CompileStatistics_lock       , Mutex  , nonleaf+2,   false);
-  def(MultiArray_lock              , Mutex  , nonleaf+2,   false); // locks SymbolTable_lock
+  def(CompiledIC_lock              , Mutex  , nonleaf+2,   false, Monitor::_safepoint_check_always);     // locks VtableStubs_lock, InlineCacheBuffer_lock
+  def(CompileTaskAlloc_lock        , Mutex  , nonleaf+2,   true,  Monitor::_safepoint_check_always);
+  def(CompileStatistics_lock       , Mutex  , nonleaf+2,   false, Monitor::_safepoint_check_always);
+  def(MultiArray_lock              , Mutex  , nonleaf+2,   false, Monitor::_safepoint_check_always);     // locks SymbolTable_lock
 
-  def(JvmtiThreadState_lock        , Mutex  , nonleaf+2,   false); // Used by JvmtiThreadState/JvmtiEventController
-  def(JvmtiPendingEvent_lock       , Monitor, nonleaf,     false); // Used by JvmtiCodeBlobEvents
-  def(Management_lock              , Mutex  , nonleaf+2,   false); // used for JVM management
+  def(JvmtiThreadState_lock        , Mutex  , nonleaf+2,   false, Monitor::_safepoint_check_always);     // Used by JvmtiThreadState/JvmtiEventController
+  def(JvmtiPendingEvent_lock       , Monitor, nonleaf,     false, Monitor::_safepoint_check_never);      // Used by JvmtiCodeBlobEvents
+  def(Management_lock              , Mutex  , nonleaf+2,   false, Monitor::_safepoint_check_always);     // used for JVM management
 
-  def(Compile_lock                 , Mutex  , nonleaf+3,   true );
-  def(MethodData_lock              , Mutex  , nonleaf+3,   false);
+  def(Compile_lock                 , Mutex  , nonleaf+3,   true,  Monitor::_safepoint_check_sometimes);
+  def(MethodData_lock              , Mutex  , nonleaf+3,   false, Monitor::_safepoint_check_always);
 
-  def(MethodCompileQueue_lock      , Monitor, nonleaf+4,   true );
-  def(Debug2_lock                  , Mutex  , nonleaf+4,   true );
-  def(Debug3_lock                  , Mutex  , nonleaf+4,   true );
-  def(ProfileVM_lock               , Monitor, special,   false); // used for profiling of the VMThread
-  def(CompileThread_lock           , Monitor, nonleaf+5,   false );
-  def(PeriodicTask_lock            , Monitor, nonleaf+5,   true);
+  def(MethodCompileQueue_lock      , Monitor, nonleaf+4,   true,  Monitor::_safepoint_check_always);
+  def(Debug2_lock                  , Mutex  , nonleaf+4,   true,  Monitor::_safepoint_check_never);
+  def(Debug3_lock                  , Mutex  , nonleaf+4,   true,  Monitor::_safepoint_check_never);
+  def(ProfileVM_lock               , Monitor, special,     false, Monitor::_safepoint_check_never);      // used for profiling of the VMThread
+  def(CompileThread_lock           , Monitor, nonleaf+5,   false, Monitor::_safepoint_check_always);
+  def(PeriodicTask_lock            , Monitor, nonleaf+5,   true,  Monitor::_safepoint_check_sometimes);
   if (WhiteBoxAPI) {
-    def(Compilation_lock           , Monitor, leaf,        false );
+    def(Compilation_lock           , Monitor, leaf,        false, Monitor::_safepoint_check_never);
   }
+
 #ifdef INCLUDE_TRACE
-  def(JfrMsg_lock                  , Monitor, leaf,        true);
-  def(JfrBuffer_lock               , Mutex,   leaf,        true);
-  def(JfrThreadGroups_lock         , Mutex,   leaf,        true);
-  def(JfrStream_lock               , Mutex,   nonleaf,     true);
-  def(JfrStacktrace_lock           , Mutex,   special,     true);
+  def(JfrMsg_lock                  , Monitor, leaf,        true,  Monitor::_safepoint_check_always);
+  def(JfrBuffer_lock               , Mutex,   leaf,        true,  Monitor::_safepoint_check_never);
+  def(JfrThreadGroups_lock         , Mutex,   leaf,        true,  Monitor::_safepoint_check_always);
+  def(JfrStream_lock               , Mutex,   nonleaf,     true,  Monitor::_safepoint_check_never);
+  def(JfrStacktrace_lock           , Mutex,   special,     true,  Monitor::_safepoint_check_sometimes);
 #endif
 
 #ifndef SUPPORTS_NATIVE_CX8
-  def(UnsafeJlong_lock             , Mutex,   special,     false);
+  def(UnsafeJlong_lock             , Mutex,   special,     false, Monitor::_safepoint_check_never);
 #endif
 }
 
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/runtime/sweeper.cpp
--- a/hotspot/src/share/vm/runtime/sweeper.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/runtime/sweeper.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -158,7 +158,7 @@
 Tickspan NMethodSweeper::_peak_sweep_time;                     // Peak time for a full sweep
 Tickspan NMethodSweeper::_peak_sweep_fraction_time;            // Peak time sweeping one fraction
 
-Monitor* NMethodSweeper::_stat_lock = new Monitor(Mutex::special, "Sweeper::Statistics", true);
+Monitor* NMethodSweeper::_stat_lock = new Monitor(Mutex::special, "Sweeper::Statistics", true, Monitor::_safepoint_check_sometimes);
 
 class MarkActivationClosure: public CodeBlobClosure {
 public:
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/runtime/thread.cpp
--- a/hotspot/src/share/vm/runtime/thread.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/runtime/thread.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -230,7 +230,8 @@
   _visited_for_critical_count = false;
 #endif
 
-  _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true);
+  _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true,
+                         Monitor::_safepoint_check_sometimes);
   _suspend_flags = 0;
 
   // thread-specific hashCode stream generator state - Marsaglia shift-xor form
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/runtime/vmThread.cpp
--- a/hotspot/src/share/vm/runtime/vmThread.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/runtime/vmThread.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -214,7 +214,8 @@
   _vm_queue = new VMOperationQueue();
   guarantee(_vm_queue != NULL, "just checking");
 
-  _terminate_lock = new Monitor(Mutex::safepoint, "VMThread::_terminate_lock", true);
+  _terminate_lock = new Monitor(Mutex::safepoint, "VMThread::_terminate_lock", true,
+                                Monitor::_safepoint_check_never);
 
   if (UsePerfData) {
     // jvmstat performance counters
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/runtime/vm_operations.cpp
--- a/hotspot/src/share/vm/runtime/vm_operations.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/runtime/vm_operations.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -391,7 +391,8 @@
   assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint already");
 
   Thread * thr_cur = ThreadLocalStorage::get_thread_slow();
-  Monitor timer(Mutex::leaf, "VM_Exit timer", true);
+  Monitor timer(Mutex::leaf, "VM_Exit timer", true,
+                Monitor::_safepoint_check_never);
 
   // Compiler threads need longer wait because they can access VM data directly
   // while in native. If they are active and some structures being used are
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/services/diagnosticFramework.cpp
--- a/hotspot/src/share/vm/services/diagnosticFramework.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/services/diagnosticFramework.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -487,7 +487,7 @@
   }
 }
 
-Mutex* DCmdFactory::_dcmdFactory_lock = new Mutex(Mutex::leaf, "DCmdFactory", true);
+Mutex* DCmdFactory::_dcmdFactory_lock = new Mutex(Mutex::leaf, "DCmdFactory", true, Monitor::_safepoint_check_never);
 bool DCmdFactory::_send_jmx_notification = false;
 
 DCmdFactory* DCmdFactory::factory(DCmdSource source, const char* name, size_t len) {
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/services/memoryManager.cpp
--- a/hotspot/src/share/vm/services/memoryManager.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/services/memoryManager.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -198,7 +198,8 @@
 GCMemoryManager::GCMemoryManager() : MemoryManager() {
   _num_collections = 0;
   _last_gc_stat = NULL;
-  _last_gc_lock = new Mutex(Mutex::leaf, "_last_gc_lock", true);
+  _last_gc_lock = new Mutex(Mutex::leaf, "_last_gc_lock", true,
+                            Monitor::_safepoint_check_never);
   _current_gc_stat = NULL;
   _num_gc_threads = 1;
   _notification_enabled = false;
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/utilities/decoder.cpp
--- a/hotspot/src/share/vm/utilities/decoder.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/utilities/decoder.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -42,7 +42,9 @@
 AbstractDecoder*  Decoder::_error_handler_decoder = NULL;
 NullDecoder       Decoder::_do_nothing_decoder;
 Mutex*            Decoder::_shared_decoder_lock = new Mutex(Mutex::native,
-                                "SharedDecoderLock");
+                                "SharedDecoderLock",
+                                false,
+                                Monitor::_safepoint_check_never);
 
 AbstractDecoder* Decoder::get_shared_instance() {
   assert(_shared_decoder_lock != NULL && _shared_decoder_lock->owned_by_self(),
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/utilities/events.hpp
--- a/hotspot/src/share/vm/utilities/events.hpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/utilities/events.hpp	Thu Dec 11 21:34:43 2014 -0500
@@ -90,7 +90,7 @@
     _length(length),
     _count(0),
     _index(0),
-    _mutex(Mutex::event, name) {
+    _mutex(Mutex::event, name, false, Monitor::_safepoint_check_never) {
     _records = new EventRecord<T>[length];
   }
 
diff -r a4075664328d -r 322d55d167be hotspot/src/share/vm/utilities/workgroup.cpp
--- a/hotspot/src/share/vm/utilities/workgroup.cpp	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/src/share/vm/utilities/workgroup.cpp	Thu Dec 11 21:34:43 2014 -0500
@@ -46,7 +46,8 @@
   // Other initialization.
   _monitor = new Monitor(/* priority */       Mutex::leaf,
                          /* name */           "WorkGroup monitor",
-                         /* allow_vm_block */ are_GC_task_threads);
+                         /* allow_vm_block */ are_GC_task_threads,
+                                              Monitor::_safepoint_check_sometimes);
   assert(monitor() != NULL, "Failed to allocate monitor");
   _terminate = false;
   _task = NULL;
@@ -378,12 +379,13 @@
 // *** WorkGangBarrierSync
 
 WorkGangBarrierSync::WorkGangBarrierSync()
-  : _monitor(Mutex::safepoint, "work gang barrier sync", true),
+  : _monitor(Mutex::safepoint, "work gang barrier sync", true,
+             Monitor::_safepoint_check_never),
     _n_workers(0), _n_completed(0), _should_reset(false), _aborted(false) {
 }
 
 WorkGangBarrierSync::WorkGangBarrierSync(uint n_workers, const char* name)
-  : _monitor(Mutex::safepoint, name, true),
+  : _monitor(Mutex::safepoint, name, true, Monitor::_safepoint_check_never),
     _n_workers(n_workers), _n_completed(0), _should_reset(false), _aborted(false) {
 }
 
diff -r a4075664328d -r 322d55d167be hotspot/test/runtime/Safepoint/AssertSafepointCheckConsistency1.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/Safepoint/AssertSafepointCheckConsistency1.java	Thu Dec 11 21:34:43 2014 -0500
@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8047290
+ * @summary Ensure that a Monitor::lock_without_safepoint_check fires an assert when it incorrectly acquires a lock which must always have safepoint checks.
+ * @library /testlibrary /testlibrary/whitebox
+ * @build AssertSafepointCheckConsistency1
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ *                              sun.hotspot.WhiteBox$WhiteBoxPermission
+ * @run main AssertSafepointCheckConsistency1
+ */
+
+import com.oracle.java.testlibrary.*;
+
+import sun.hotspot.WhiteBox;
+
+public class AssertSafepointCheckConsistency1 {
+    public static void main(String args[]) throws Exception {
+        if (args.length > 0) {
+            WhiteBox.getWhiteBox().assertMatchingSafepointCalls(true, true);
+        }
+        if (Platform.isDebugBuild()){
+            ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
+                  "-Xbootclasspath/a:.",
+                  "-XX:+UnlockDiagnosticVMOptions",
+                  "-XX:+WhiteBoxAPI",
+                  "-XX:-TransmitErrorReport",
+                  "-Xmx32m",
+                  "AssertSafepointCheckConsistency1",
+                  "test");
+            OutputAnalyzer output = new OutputAnalyzer(pb.start());
+            output.shouldContain("assert").shouldContain("always");
+        }
+    }
+}
+
+
diff -r a4075664328d -r 322d55d167be hotspot/test/runtime/Safepoint/AssertSafepointCheckConsistency2.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/Safepoint/AssertSafepointCheckConsistency2.java	Thu Dec 11 21:34:43 2014 -0500
@@ -0,0 +1,58 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8047290
+ * @summary Ensure that a Monitor::lock fires an assert when it incorrectly acquires a lock which must never have safepoint checks.
+ * @library /testlibrary /testlibrary/whitebox
+ * @build AssertSafepointCheckConsistency2
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ *                              sun.hotspot.WhiteBox$WhiteBoxPermission
+ * @run main AssertSafepointCheckConsistency2
+ */
+
+import com.oracle.java.testlibrary.*;
+
+import sun.hotspot.WhiteBox;
+
+public class AssertSafepointCheckConsistency2 {
+    public static void main(String args[]) throws Exception {
+        if (args.length > 0) {
+            WhiteBox.getWhiteBox().assertMatchingSafepointCalls(false, false);
+        }
+        if (Platform.isDebugBuild()){
+            ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
+                  "-Xbootclasspath/a:.",
+                  "-XX:+UnlockDiagnosticVMOptions",
+                  "-XX:+WhiteBoxAPI",
+                  "-XX:-TransmitErrorReport",
+                  "-Xmx32m",
+                  "AssertSafepointCheckConsistency2",
+                  "test");
+
+            OutputAnalyzer output = new OutputAnalyzer(pb.start());
+            output.shouldContain("assert").shouldContain("never");
+        }
+    }
+}
diff -r a4075664328d -r 322d55d167be hotspot/test/runtime/Safepoint/AssertSafepointCheckConsistency3.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/Safepoint/AssertSafepointCheckConsistency3.java	Thu Dec 11 21:34:43 2014 -0500
@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8047290
+ * @summary Ensure that Monitor::lock_without_safepoint_check does not assert when it correctly acquires a lock which must never have safepoint checks.
+ * @library /testlibrary /testlibrary/whitebox
+ * @build AssertSafepointCheckConsistency3
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ *                              sun.hotspot.WhiteBox$WhiteBoxPermission
+ * @run main AssertSafepointCheckConsistency3
+ */
+
+import com.oracle.java.testlibrary.*;
+
+import sun.hotspot.WhiteBox;
+
+public class AssertSafepointCheckConsistency3 {
+    public static void main(String args[]) throws Exception {
+        if (args.length > 0) {
+            WhiteBox.getWhiteBox().assertMatchingSafepointCalls(false, true);
+        }
+        if (Platform.isDebugBuild()){
+            ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
+                  "-Xbootclasspath/a:.",
+                  "-XX:+UnlockDiagnosticVMOptions",
+                  "-XX:+WhiteBoxAPI",
+                  "-XX:-TransmitErrorReport",
+                  "-Xmx32m",
+                  "AssertSafepointCheckConsistency3",
+                  "test");
+
+            OutputAnalyzer output = new OutputAnalyzer(pb.start());
+            output.shouldNotContain("assert");
+            output.shouldNotContain("never");
+            output.shouldNotContain("always");
+        }
+    }
+}
diff -r a4075664328d -r 322d55d167be hotspot/test/runtime/Safepoint/AssertSafepointCheckConsistency4.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/runtime/Safepoint/AssertSafepointCheckConsistency4.java	Thu Dec 11 21:34:43 2014 -0500
@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8047290
+ * @summary Ensure that Monitor::lock does not assert when it correctly acquires a lock which must always have safepoint checks.
+ * @library /testlibrary /testlibrary/whitebox
+ * @build AssertSafepointCheckConsistency4
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ *                              sun.hotspot.WhiteBox$WhiteBoxPermission
+ * @run main AssertSafepointCheckConsistency4
+ */
+
+import com.oracle.java.testlibrary.*;
+
+import sun.hotspot.WhiteBox;
+
+public class AssertSafepointCheckConsistency4 {
+    public static void main(String args[]) throws Exception {
+        if (args.length > 0) {
+            WhiteBox.getWhiteBox().assertMatchingSafepointCalls(true, false);
+        }
+        if (Platform.isDebugBuild()){
+            ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
+               "-Xbootclasspath/a:.",
+               "-XX:+UnlockDiagnosticVMOptions",
+               "-XX:+WhiteBoxAPI",
+               "-XX:-TransmitErrorReport",
+               "-Xmx32m",
+               "AssertSafepointCheckConsistency4",
+               "test");
+
+            OutputAnalyzer output = new OutputAnalyzer(pb.start());
+            output.shouldNotContain("assert");
+            output.shouldNotContain("never");
+            output.shouldNotContain("always");
+        }
+    }
+}
+
+
diff -r a4075664328d -r 322d55d167be hotspot/test/testlibrary/whitebox/sun/hotspot/WhiteBox.java
--- a/hotspot/test/testlibrary/whitebox/sun/hotspot/WhiteBox.java	Mon Dec 08 00:15:55 2014 -0800
+++ b/hotspot/test/testlibrary/whitebox/sun/hotspot/WhiteBox.java	Thu Dec 11 21:34:43 2014 -0500
@@ -240,4 +240,6 @@
     return offset;
   }
 
+  // Safepoint Checking
+  public native void assertMatchingSafepointCalls(boolean mutexSafepointValue, boolean attemptedNoSafepointValue);
 }