6458402: 3 jvmti tests fail with CMS and +ExplicitGCInvokesConcurrent

Summary: Make JvmtiGCMark safe to run non-safepoint and instrument CMS
Reviewed-by: ysr, dcubed

hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp

@@ -3478,6 +3478,7 @@ void CMSCollector::checkpointRootsInitial(bool asynch) {
   assert(_collectorState == InitialMarking, "Wrong collector state");
   check_correct_thread_executing();
   TraceCMSMemoryManagerStats tms(_collectorState);
+
   ReferenceProcessor* rp = ref_processor();
   SpecializationStats::clear();
   assert(_restart_addr == NULL, "Control point invariant");
@@ -5940,11 +5941,6 @@ void CMSCollector::refProcessingWork(bool asynch, bool clear_all_soft_refs) {
   }
   rp->verify_no_references_recorded();
   assert(!rp->discovery_enabled(), "should have been disabled");
-
-  // JVMTI object tagging is based on JNI weak refs. If any of these
-  // refs were cleared then JVMTI needs to update its maps and
-  // maybe post ObjectFrees to agents.
-  JvmtiExport::cms_ref_processing_epilogue();
 }
 
 #ifndef PRODUCT
@@ -6305,6 +6301,7 @@ void CMSCollector::do_CMS_operation(CMS_op_type op) {
 
   switch (op) {
     case CMS_op_checkpointRootsInitial: {
+      SvcGCMarker sgcm(SvcGCMarker::OTHER);
       checkpointRootsInitial(true);       // asynch
       if (PrintGC) {
         _cmsGen->printOccupancy("initial-mark");
@@ -6312,6 +6309,7 @@ void CMSCollector::do_CMS_operation(CMS_op_type op) {
       break;
     }
     case CMS_op_checkpointRootsFinal: {
+      SvcGCMarker sgcm(SvcGCMarker::OTHER);
       checkpointRootsFinal(true,    // asynch
                            false,   // !clear_all_soft_refs
                            false);  // !init_mark_was_synchronous

hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp

@@ -31,6 +31,7 @@
 #include "gc_implementation/g1/g1RemSet.hpp"
 #include "gc_implementation/g1/heapRegionRemSet.hpp"
 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
+#include "gc_implementation/shared/vmGCOperations.hpp"
 #include "memory/genOopClosures.inline.hpp"
 #include "memory/referencePolicy.hpp"
 #include "memory/resourceArea.hpp"
@@ -1142,6 +1143,8 @@ void ConcurrentMark::checkpointRootsFinal(bool clear_all_soft_refs) {
     return;
   }
 
+  SvcGCMarker sgcm(SvcGCMarker::OTHER);
+
   if (VerifyDuringGC) {
     HandleMark hm;  // handle scope
     gclog_or_tty->print(" VerifyDuringGC:(before)");

hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp

@@ -1192,7 +1192,7 @@ bool G1CollectedHeap::do_collection(bool explicit_gc,
     return false;
   }
 
-  DTraceGCProbeMarker gc_probe_marker(true /* full */);
+  SvcGCMarker sgcm(SvcGCMarker::FULL);
   ResourceMark rm;
 
   if (PrintHeapAtGC) {
@@ -3214,7 +3214,7 @@ G1CollectedHeap::do_collection_pause_at_safepoint(double target_pause_time_ms) {
     return false;
   }
 
-  DTraceGCProbeMarker gc_probe_marker(false /* full */);
+  SvcGCMarker sgcm(SvcGCMarker::MINOR);
   ResourceMark rm;
 
   if (PrintHeapAtGC) {

hotspot/src/share/vm/gc_implementation/g1/vm_operations_g1.cpp

@@ -38,7 +38,6 @@ VM_G1CollectForAllocation::VM_G1CollectForAllocation(
 }
 
 void VM_G1CollectForAllocation::doit() {
-  JvmtiGCForAllocationMarker jgcm;
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
   _result = g1h->satisfy_failed_allocation(_word_size, &_pause_succeeded);
   assert(_result == NULL || _pause_succeeded,
@@ -46,7 +45,6 @@ void VM_G1CollectForAllocation::doit() {
 }
 
 void VM_G1CollectFull::doit() {
-  JvmtiGCFullMarker jgcm;
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
   GCCauseSetter x(g1h, _gc_cause);
   g1h->do_full_collection(false /* clear_all_soft_refs */);
@@ -72,7 +70,6 @@ VM_G1IncCollectionPause::VM_G1IncCollectionPause(
 }
 
 void VM_G1IncCollectionPause::doit() {
-  JvmtiGCForAllocationMarker jgcm;
   G1CollectedHeap* g1h = G1CollectedHeap::heap();
   assert(!_should_initiate_conc_mark ||
   ((_gc_cause == GCCause::_gc_locker && GCLockerInvokesConcurrent) ||

hotspot/src/share/vm/gc_implementation/parallelScavenge/vmPSOperations.cpp

@@ -42,8 +42,7 @@ VM_ParallelGCFailedAllocation::VM_ParallelGCFailedAllocation(size_t size,
 }
 
 void VM_ParallelGCFailedAllocation::doit() {
-  JvmtiGCForAllocationMarker jgcm;
-  notify_gc_begin(false);
+  SvcGCMarker sgcm(SvcGCMarker::MINOR);
 
   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "must be a ParallelScavengeHeap");
@@ -54,8 +53,6 @@ void VM_ParallelGCFailedAllocation::doit() {
   if (_result == NULL && GC_locker::is_active_and_needs_gc()) {
     set_gc_locked();
   }
-
-  notify_gc_end();
 }
 
 VM_ParallelGCFailedPermanentAllocation::VM_ParallelGCFailedPermanentAllocation(size_t size,
@@ -67,8 +64,7 @@ VM_ParallelGCFailedPermanentAllocation::VM_ParallelGCFailedPermanentAllocation(s
 }
 
 void VM_ParallelGCFailedPermanentAllocation::doit() {
-  JvmtiGCFullMarker jgcm;
-  notify_gc_begin(true);
+  SvcGCMarker sgcm(SvcGCMarker::FULL);
 
   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "must be a ParallelScavengeHeap");
@@ -78,7 +74,6 @@ void VM_ParallelGCFailedPermanentAllocation::doit() {
   if (_result == NULL && GC_locker::is_active_and_needs_gc()) {
     set_gc_locked();
   }
-  notify_gc_end();
 }
 
 // Only used for System.gc() calls
@@ -91,8 +86,7 @@ VM_ParallelGCSystemGC::VM_ParallelGCSystemGC(unsigned int gc_count,
 }
 
 void VM_ParallelGCSystemGC::doit() {
-  JvmtiGCFullMarker jgcm;
-  notify_gc_begin(true);
+  SvcGCMarker sgcm(SvcGCMarker::FULL);
 
   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap,
@@ -106,5 +100,4 @@ void VM_ParallelGCSystemGC::doit() {
   } else {
     heap->invoke_full_gc(false);
   }
-  notify_gc_end();
 }

hotspot/src/share/vm/gc_implementation/shared/vmGCOperations.cpp

@@ -31,7 +31,6 @@
 #include "memory/oopFactory.hpp"
 #include "oops/instanceKlass.hpp"
 #include "oops/instanceRefKlass.hpp"
-#include "prims/jvmtiExport.hpp"
 #include "runtime/handles.inline.hpp"
 #include "runtime/init.hpp"
 #include "runtime/interfaceSupport.hpp"
@@ -40,6 +39,7 @@
 #ifndef SERIALGC
 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
 #endif
+
 HS_DTRACE_PROBE_DECL1(hotspot, gc__begin, bool);
 HS_DTRACE_PROBE_DECL(hotspot, gc__end);
 
@@ -158,8 +158,7 @@ void VM_GC_HeapInspection::doit() {
 
 
 void VM_GenCollectForAllocation::doit() {
-  JvmtiGCForAllocationMarker jgcm;
-  notify_gc_begin(false);
+  SvcGCMarker sgcm(SvcGCMarker::MINOR);
 
   GenCollectedHeap* gch = GenCollectedHeap::heap();
   GCCauseSetter gccs(gch, _gc_cause);
@@ -169,22 +168,19 @@ void VM_GenCollectForAllocation::doit() {
   if (_res == NULL && GC_locker::is_active_and_needs_gc()) {
     set_gc_locked();
   }
-  notify_gc_end();
 }
 
 void VM_GenCollectFull::doit() {
-  JvmtiGCFullMarker jgcm;
-  notify_gc_begin(true);
+  SvcGCMarker sgcm(SvcGCMarker::FULL);
 
   GenCollectedHeap* gch = GenCollectedHeap::heap();
   GCCauseSetter gccs(gch, _gc_cause);
   gch->do_full_collection(gch->must_clear_all_soft_refs(), _max_level);
-  notify_gc_end();
 }
 
 void VM_GenCollectForPermanentAllocation::doit() {
-  JvmtiGCForAllocationMarker jgcm;
-  notify_gc_begin(true);
+  SvcGCMarker sgcm(SvcGCMarker::FULL);
+
   SharedHeap* heap = (SharedHeap*)Universe::heap();
   GCCauseSetter gccs(heap, _gc_cause);
   switch (heap->kind()) {
@@ -209,5 +205,4 @@ void VM_GenCollectForPermanentAllocation::doit() {
   if (_res == NULL && GC_locker::is_active_and_needs_gc()) {
     set_gc_locked();
   }
-  notify_gc_end();
 }

hotspot/src/share/vm/gc_implementation/shared/vmGCOperations.hpp

@@ -30,6 +30,7 @@
 #include "runtime/jniHandles.hpp"
 #include "runtime/synchronizer.hpp"
 #include "runtime/vm_operations.hpp"
+#include "prims/jvmtiExport.hpp"
 
 // The following class hierarchy represents
 // a set of operations (VM_Operation) related to GC.
@@ -209,13 +210,17 @@ class VM_GenCollectForPermanentAllocation: public VM_GC_Operation {
   HeapWord* result() const       { return _res; }
 };
 
-class DTraceGCProbeMarker : public StackObj {
-public:
-  DTraceGCProbeMarker(bool full) {
-    VM_GC_Operation::notify_gc_begin(full);
+class SvcGCMarker : public StackObj {
+ private:
+  JvmtiGCMarker _jgcm;
+ public:
+  typedef enum { MINOR, FULL, OTHER } reason_type;
+
+  SvcGCMarker(reason_type reason ) {
+    VM_GC_Operation::notify_gc_begin(reason == FULL);
   }
 
-  ~DTraceGCProbeMarker() {
+  ~SvcGCMarker() {
     VM_GC_Operation::notify_gc_end();
   }
 };

hotspot/src/share/vm/prims/jvmti.xml

@@ -13048,8 +13048,8 @@ myInit() {
   <event label="Garbage Collection Start"
 	 id="GarbageCollectionStart" const="JVMTI_EVENT_GARBAGE_COLLECTION_START" num="81">
     <description>
-      A Garbage Collection Start event is sent when a full cycle
-      garbage collection begins.
+      A Garbage Collection Start event is sent when a 
+      garbage collection pause begins.
       Only stop-the-world collections are reported--that is, collections during
       which all threads cease to modify the state of the Java virtual machine.
       This means that some collectors will never generate these events.
@@ -13075,8 +13075,8 @@ myInit() {
   <event label="Garbage Collection Finish"
 	 id="GarbageCollectionFinish" const="JVMTI_EVENT_GARBAGE_COLLECTION_FINISH" num="82">
     <description>
-      A Garbage Collection Finish event is sent when a full 
-      garbage collection cycle ends.
+      A Garbage Collection Finish event is sent when a
+      garbage collection pause ends.
       This event is sent while the VM is still stopped, thus
       the event handler must not use JNI functions and
       must not use <jvmti/> functions except those which

hotspot/src/share/vm/prims/jvmtiExport.cpp

@@ -2358,15 +2358,6 @@ jint JvmtiExport::load_agent_library(AttachOperation* op, outputStream* st) {
 }
 #endif // SERVICES_KERNEL
 
-// CMS has completed referencing processing so may need to update
-// tag maps.
-void JvmtiExport::cms_ref_processing_epilogue() {
-  if (JvmtiEnv::environments_might_exist()) {
-    JvmtiTagMap::cms_ref_processing_epilogue();
-  }
-}
-
-
 ////////////////////////////////////////////////////////////////////////////////////////////////
 
 // Setup current current thread for event collection.
@@ -2536,36 +2527,20 @@ NoJvmtiVMObjectAllocMark::~NoJvmtiVMObjectAllocMark() {
   }
 };
 
-JvmtiGCMarker::JvmtiGCMarker(bool full) : _full(full), _invocation_count(0) {
-  assert(Thread::current()->is_VM_thread(), "wrong thread");
-
+JvmtiGCMarker::JvmtiGCMarker() {
   // if there aren't any JVMTI environments then nothing to do
   if (!JvmtiEnv::environments_might_exist()) {
     return;
   }
 
-  if (ForceFullGCJVMTIEpilogues) {
-    // force 'Full GC' was done semantics for JVMTI GC epilogues
-    _full = true;
-  }
-
-  // GarbageCollectionStart event posted from VM thread - okay because
-  // JVMTI is clear that the "world is stopped" and callback shouldn't
-  // try to call into the VM.
   if (JvmtiExport::should_post_garbage_collection_start()) {
     JvmtiExport::post_garbage_collection_start();
   }
 
-  // if "full" is false it probably means this is a scavenge of the young
-  // generation. However it could turn out that a "full" GC is required
-  // so we record the number of collections so that it can be checked in
-  // the destructor.
-  if (!_full) {
-    _invocation_count = Universe::heap()->total_full_collections();
+  if (SafepointSynchronize::is_at_safepoint()) {
+    // Do clean up tasks that need to be done at a safepoint
+    JvmtiEnvBase::check_for_periodic_clean_up();
   }
-
-  // Do clean up tasks that need to be done at a safepoint
-  JvmtiEnvBase::check_for_periodic_clean_up();
 }
 
 JvmtiGCMarker::~JvmtiGCMarker() {
@@ -2578,21 +2553,5 @@ JvmtiGCMarker::~JvmtiGCMarker() {
   if (JvmtiExport::should_post_garbage_collection_finish()) {
     JvmtiExport::post_garbage_collection_finish();
   }
-
-  // we might have initially started out doing a scavenge of the young
-  // generation but could have ended up doing a "full" GC - check the
-  // GC count to see.
-  if (!_full) {
-    _full = (_invocation_count != Universe::heap()->total_full_collections());
-  }
-
-  // Full collection probably means the perm generation has been GC'ed
-  // so we clear the breakpoint cache.
-  if (_full) {
-    JvmtiCurrentBreakpoints::gc_epilogue();
-  }
-
-  // Notify heap/object tagging support
-  JvmtiTagMap::gc_epilogue(_full);
 }
 #endif // JVMTI_KERNEL

hotspot/src/share/vm/prims/jvmtiExport.hpp

@@ -356,9 +356,6 @@ class JvmtiExport : public AllStatic {
 
   // SetNativeMethodPrefix support
   static char** get_all_native_method_prefixes(int* count_ptr);
-
-  // call after CMS has completed referencing processing
-  static void cms_ref_processing_epilogue() KERNEL_RETURN;
 };
 
 // Support class used by JvmtiDynamicCodeEventCollector and others. It
@@ -492,55 +489,11 @@ class NoJvmtiVMObjectAllocMark : public StackObj {
 
 // Base class for reporting GC events to JVMTI.
 class JvmtiGCMarker : public StackObj {
- private:
-  bool _full;                           // marks a "full" GC
-  unsigned int _invocation_count;       // GC invocation count
- protected:
-  JvmtiGCMarker(bool full) KERNEL_RETURN;       // protected
-  ~JvmtiGCMarker() KERNEL_RETURN;               // protected
-};
-
-
-// Support class used to report GC events to JVMTI. The class is stack
-// allocated and should be placed in the doit() implementation of all
-// vm operations that do a stop-the-world GC for failed allocation.
-//
-// Usage :-
-//
-// void VM_GenCollectForAllocation::doit() {
-//   JvmtiGCForAllocationMarker jgcm;
-//   :
-// }
-//
-// If jvmti is not enabled the constructor and destructor is essentially
-// a no-op (no overhead).
-//
-class JvmtiGCForAllocationMarker : public JvmtiGCMarker {
  public:
-  JvmtiGCForAllocationMarker() : JvmtiGCMarker(false) {
-  }
-};
-
-// Support class used to report GC events to JVMTI. The class is stack
-// allocated and should be placed in the doit() implementation of all
-// vm operations that do a "full" stop-the-world GC. This class differs
-// from JvmtiGCForAllocationMarker in that this class assumes that a
-// "full" GC will happen.
-//
-// Usage :-
-//
-// void VM_GenCollectFull::doit() {
-//   JvmtiGCFullMarker jgcm;
-//   :
-// }
-//
-class JvmtiGCFullMarker : public JvmtiGCMarker {
- public:
-  JvmtiGCFullMarker() : JvmtiGCMarker(true) {
-  }
+  JvmtiGCMarker() KERNEL_RETURN;
+  ~JvmtiGCMarker() KERNEL_RETURN;
 };
 
-
 // JvmtiHideSingleStepping is a helper class for hiding
 // internal single step events.
 class JvmtiHideSingleStepping : public StackObj {

hotspot/src/share/vm/prims/jvmtiImpl.cpp

@@ -212,14 +212,7 @@ void GrowableCache::oops_do(OopClosure* f) {
   for (int i=0; i<len; i++) {
     GrowableElement *e = _elements->at(i);
     e->oops_do(f);
-  }
-}
-
-void GrowableCache::gc_epilogue() {
-  int len = _elements->length();
-  // recompute the new cache value after GC
-  for (int i=0; i<len; i++) {
-    _cache[i] = _elements->at(i)->getCacheValue();
+    _cache[i] = e->getCacheValue();
   }
 }
 
@@ -401,10 +394,6 @@ void  JvmtiBreakpoints::oops_do(OopClosure* f) {
   _bps.oops_do(f);
 }
 
-void  JvmtiBreakpoints::gc_epilogue() {
-  _bps.gc_epilogue();
-}
-
 void  JvmtiBreakpoints::print() {
 #ifndef PRODUCT
   ResourceMark rm;
@@ -534,13 +523,6 @@ void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) {
   }
 }
 
-void JvmtiCurrentBreakpoints::gc_epilogue() {
-  if (_jvmti_breakpoints != NULL) {
-    _jvmti_breakpoints->gc_epilogue();
-  }
-}
-
-
 ///////////////////////////////////////////////////////////////
 //
 // class VM_GetOrSetLocal

hotspot/src/share/vm/prims/jvmtiImpl.hpp

@@ -117,7 +117,6 @@ public:
   void clear();
   // apply f to every element and update the cache
   void oops_do(OopClosure* f);
-  void gc_epilogue();
 };
 
 
@@ -149,7 +148,6 @@ public:
   void remove (int index)               { _cache.remove(index); }
   void clear()                          { _cache.clear(); }
   void oops_do(OopClosure* f)           { _cache.oops_do(f); }
-  void gc_epilogue()                    { _cache.gc_epilogue(); }
 };
 
 
@@ -278,7 +276,6 @@ public:
 
   int length();
   void oops_do(OopClosure* f);
-  void gc_epilogue();
   void print();
 
   int  set(JvmtiBreakpoint& bp);
@@ -328,7 +325,6 @@ public:
   static inline bool is_breakpoint(address bcp);
 
   static void oops_do(OopClosure* f);
-  static void gc_epilogue();
 };
 
 // quickly test whether the bcp matches a cached breakpoint in the list

hotspot/src/share/vm/prims/jvmtiTagMap.hpp

@@ -45,17 +45,12 @@ class JvmtiTagMap :  public CHeapObj {
  private:
 
   enum{
-    n_hashmaps = 2,                                 // encapsulates 2 hashmaps
-    max_free_entries = 4096                         // maximum number of free entries per env
+    max_free_entries = 4096         // maximum number of free entries per env
   };
 
-  // memory region for young generation
-  static MemRegion _young_gen;
-  static void get_young_generation();
-
   JvmtiEnv*             _env;                       // the jvmti environment
   Mutex                 _lock;                      // lock for this tag map
-  JvmtiTagHashmap*      _hashmap[n_hashmaps];       // the hashmaps
+  JvmtiTagHashmap*      _hashmap;                   // the hashmap
 
   JvmtiTagHashmapEntry* _free_entries;              // free list for this environment
   int _free_entries_count;                          // number of entries on the free list
@@ -67,11 +62,7 @@ class JvmtiTagMap :  public CHeapObj {
   inline Mutex* lock()                      { return &_lock; }
   inline JvmtiEnv* env() const              { return _env; }
 
-  // rehash tags maps for generation start to end
-  void rehash(int start, int end);
-
-  // indicates if the object is in the young generation
-  static bool is_in_young(oop o);
+  void do_weak_oops(BoolObjectClosure* is_alive, OopClosure* f);
 
   // iterate over all entries in this tag map
   void entry_iterate(JvmtiTagHashmapEntryClosure* closure);
@@ -81,11 +72,10 @@ class JvmtiTagMap :  public CHeapObj {
   // indicates if this tag map is locked
   bool is_locked()                          { return lock()->is_locked(); }
 
-  // return the appropriate hashmap for a given object
-  JvmtiTagHashmap* hashmap_for(oop o);
+  JvmtiTagHashmap* hashmap() { return _hashmap; }
 
   // create/destroy entries
-  JvmtiTagHashmapEntry* create_entry(jweak ref, jlong tag);
+  JvmtiTagHashmapEntry* create_entry(oop ref, jlong tag);
   void destroy_entry(JvmtiTagHashmapEntry* entry);
 
   // returns true if the hashmaps are empty
@@ -134,11 +124,8 @@ class JvmtiTagMap :  public CHeapObj {
                                    jint* count_ptr, jobject** object_result_ptr,
                                    jlong** tag_result_ptr);
 
-  // call post-GC to rehash the tag maps.
-  static void gc_epilogue(bool full);
-
-  // call after referencing processing has completed (CMS)
-  static void cms_ref_processing_epilogue();
+  static void weak_oops_do(
+      BoolObjectClosure* is_alive, OopClosure* f) KERNEL_RETURN;
 };
 
 #endif // SHARE_VM_PRIMS_JVMTITAGMAP_HPP

hotspot/src/share/vm/runtime/globals.hpp

@@ -1198,9 +1198,6 @@ class CommandLineFlags {
   product(ccstr, TraceJVMTI, NULL,                                          \
           "Trace flags for JVMTI functions and events")                     \
                                                                             \
-  product(bool, ForceFullGCJVMTIEpilogues, false,                           \
-          "Force 'Full GC' was done semantics for JVMTI GC epilogues")      \
-                                                                            \
   /* This option can change an EMCP method into an obsolete method. */      \
   /* This can affect tests that except specific methods to be EMCP. */      \
   /* This option should be used with caution. */                            \

hotspot/src/share/vm/runtime/jniHandles.cpp

@@ -25,6 +25,7 @@
 #include "precompiled.hpp"
 #include "classfile/systemDictionary.hpp"
 #include "oops/oop.inline.hpp"
+#include "prims/jvmtiTagMap.hpp"
 #include "runtime/jniHandles.hpp"
 #include "runtime/mutexLocker.hpp"
 #ifdef TARGET_OS_FAMILY_linux
@@ -428,6 +429,12 @@ void JNIHandleBlock::weak_oops_do(BoolObjectClosure* is_alive,
       break;
     }
   }
+
+  /*
+   * JvmtiTagMap may also contain weak oops.  The iteration of it is placed
+   * here so that we don't need to add it to each of the collectors.
+   */
+  JvmtiTagMap::weak_oops_do(is_alive, f);
 }