# HG changeset patch # User kamg # Date 1294697693 18000 # Node ID 7246a374a9f2edc3a9730d28ac59e26f5a14a542 # Parent e31d8c656c5b4b87a97c69814af07683a70e348a 6458402: 3 jvmti tests fail with CMS and +ExplicitGCInvokesConcurrent Summary: Make JvmtiGCMark safe to run non-safepoint and instrument CMS Reviewed-by: ysr, dcubed diff -r e31d8c656c5b -r 7246a374a9f2 src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp --- a/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Mon Jan 10 09:23:20 2011 -0800 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Mon Jan 10 17:14:53 2011 -0500 @@ -3478,6 +3478,7 @@ 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 @@ } 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 @@ switch (op) { case CMS_op_checkpointRootsInitial: { + SvcGCMarker sgcm(SvcGCMarker::OTHER); checkpointRootsInitial(true); // asynch if (PrintGC) { _cmsGen->printOccupancy("initial-mark"); @@ -6312,6 +6309,7 @@ break; } case CMS_op_checkpointRootsFinal: { + SvcGCMarker sgcm(SvcGCMarker::OTHER); checkpointRootsFinal(true, // asynch false, // !clear_all_soft_refs false); // !init_mark_was_synchronous diff -r e31d8c656c5b -r 7246a374a9f2 src/share/vm/gc_implementation/g1/concurrentMark.cpp --- a/src/share/vm/gc_implementation/g1/concurrentMark.cpp Mon Jan 10 09:23:20 2011 -0800 +++ b/src/share/vm/gc_implementation/g1/concurrentMark.cpp Mon Jan 10 17:14:53 2011 -0500 @@ -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 @@ return; } + SvcGCMarker sgcm(SvcGCMarker::OTHER); + if (VerifyDuringGC) { HandleMark hm; // handle scope gclog_or_tty->print(" VerifyDuringGC:(before)"); diff -r e31d8c656c5b -r 7246a374a9f2 src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp --- a/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Mon Jan 10 09:23:20 2011 -0800 +++ b/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Mon Jan 10 17:14:53 2011 -0500 @@ -1192,7 +1192,7 @@ return false; } - DTraceGCProbeMarker gc_probe_marker(true /* full */); + SvcGCMarker sgcm(SvcGCMarker::FULL); ResourceMark rm; if (PrintHeapAtGC) { @@ -3214,7 +3214,7 @@ return false; } - DTraceGCProbeMarker gc_probe_marker(false /* full */); + SvcGCMarker sgcm(SvcGCMarker::MINOR); ResourceMark rm; if (PrintHeapAtGC) { diff -r e31d8c656c5b -r 7246a374a9f2 src/share/vm/gc_implementation/g1/vm_operations_g1.cpp --- a/src/share/vm/gc_implementation/g1/vm_operations_g1.cpp Mon Jan 10 09:23:20 2011 -0800 +++ b/src/share/vm/gc_implementation/g1/vm_operations_g1.cpp Mon Jan 10 17:14:53 2011 -0500 @@ -38,7 +38,6 @@ } 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_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 @@ } void VM_G1IncCollectionPause::doit() { - JvmtiGCForAllocationMarker jgcm; G1CollectedHeap* g1h = G1CollectedHeap::heap(); assert(!_should_initiate_conc_mark || ((_gc_cause == GCCause::_gc_locker && GCLockerInvokesConcurrent) || diff -r e31d8c656c5b -r 7246a374a9f2 src/share/vm/gc_implementation/parallelScavenge/vmPSOperations.cpp --- a/src/share/vm/gc_implementation/parallelScavenge/vmPSOperations.cpp Mon Jan 10 09:23:20 2011 -0800 +++ b/src/share/vm/gc_implementation/parallelScavenge/vmPSOperations.cpp Mon Jan 10 17:14:53 2011 -0500 @@ -42,8 +42,7 @@ } 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 @@ 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 @@ } 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 @@ 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 @@ } 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 @@ } else { heap->invoke_full_gc(false); } - notify_gc_end(); } diff -r e31d8c656c5b -r 7246a374a9f2 src/share/vm/gc_implementation/shared/vmGCOperations.cpp --- a/src/share/vm/gc_implementation/shared/vmGCOperations.cpp Mon Jan 10 09:23:20 2011 -0800 +++ b/src/share/vm/gc_implementation/shared/vmGCOperations.cpp Mon Jan 10 17:14:53 2011 -0500 @@ -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_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 @@ 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 @@ if (_res == NULL && GC_locker::is_active_and_needs_gc()) { set_gc_locked(); } - notify_gc_end(); } diff -r e31d8c656c5b -r 7246a374a9f2 src/share/vm/gc_implementation/shared/vmGCOperations.hpp --- a/src/share/vm/gc_implementation/shared/vmGCOperations.hpp Mon Jan 10 09:23:20 2011 -0800 +++ b/src/share/vm/gc_implementation/shared/vmGCOperations.hpp Mon Jan 10 17:14:53 2011 -0500 @@ -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 @@ 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(); } }; diff -r e31d8c656c5b -r 7246a374a9f2 src/share/vm/prims/jvmti.xml --- a/src/share/vm/prims/jvmti.xml Mon Jan 10 09:23:20 2011 -0800 +++ b/src/share/vm/prims/jvmti.xml Mon Jan 10 17:14:53 2011 -0500 @@ -13048,8 +13048,8 @@ - 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 @@ - 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 functions except those which diff -r e31d8c656c5b -r 7246a374a9f2 src/share/vm/prims/jvmtiExport.cpp --- a/src/share/vm/prims/jvmtiExport.cpp Mon Jan 10 09:23:20 2011 -0800 +++ b/src/share/vm/prims/jvmtiExport.cpp Mon Jan 10 17:14:53 2011 -0500 @@ -2358,15 +2358,6 @@ } #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 @@ } }; -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 @@ 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 diff -r e31d8c656c5b -r 7246a374a9f2 src/share/vm/prims/jvmtiExport.hpp --- a/src/share/vm/prims/jvmtiExport.hpp Mon Jan 10 09:23:20 2011 -0800 +++ b/src/share/vm/prims/jvmtiExport.hpp Mon Jan 10 17:14:53 2011 -0500 @@ -356,9 +356,6 @@ // 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 @@ // 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 + public: + JvmtiGCMarker() KERNEL_RETURN; + ~JvmtiGCMarker() KERNEL_RETURN; }; - -// 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) { - } -}; - - // JvmtiHideSingleStepping is a helper class for hiding // internal single step events. class JvmtiHideSingleStepping : public StackObj { diff -r e31d8c656c5b -r 7246a374a9f2 src/share/vm/prims/jvmtiImpl.cpp --- a/src/share/vm/prims/jvmtiImpl.cpp Mon Jan 10 09:23:20 2011 -0800 +++ b/src/share/vm/prims/jvmtiImpl.cpp Mon Jan 10 17:14:53 2011 -0500 @@ -212,14 +212,7 @@ for (int i=0; iat(i); e->oops_do(f); - } -} - -void GrowableCache::gc_epilogue() { - int len = _elements->length(); - // recompute the new cache value after GC - for (int i=0; iat(i)->getCacheValue(); + _cache[i] = e->getCacheValue(); } } @@ -401,10 +394,6 @@ _bps.oops_do(f); } -void JvmtiBreakpoints::gc_epilogue() { - _bps.gc_epilogue(); -} - void JvmtiBreakpoints::print() { #ifndef PRODUCT ResourceMark rm; @@ -534,13 +523,6 @@ } } -void JvmtiCurrentBreakpoints::gc_epilogue() { - if (_jvmti_breakpoints != NULL) { - _jvmti_breakpoints->gc_epilogue(); - } -} - - /////////////////////////////////////////////////////////////// // // class VM_GetOrSetLocal diff -r e31d8c656c5b -r 7246a374a9f2 src/share/vm/prims/jvmtiImpl.hpp --- a/src/share/vm/prims/jvmtiImpl.hpp Mon Jan 10 09:23:20 2011 -0800 +++ b/src/share/vm/prims/jvmtiImpl.hpp Mon Jan 10 17:14:53 2011 -0500 @@ -117,7 +117,6 @@ void clear(); // apply f to every element and update the cache void oops_do(OopClosure* f); - void gc_epilogue(); }; @@ -149,7 +148,6 @@ 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 @@ int length(); void oops_do(OopClosure* f); - void gc_epilogue(); void print(); int set(JvmtiBreakpoint& bp); @@ -328,7 +325,6 @@ 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 diff -r e31d8c656c5b -r 7246a374a9f2 src/share/vm/prims/jvmtiTagMap.cpp --- a/src/share/vm/prims/jvmtiTagMap.cpp Mon Jan 10 09:23:20 2011 -0800 +++ b/src/share/vm/prims/jvmtiTagMap.cpp Mon Jan 10 17:14:53 2011 -0500 @@ -50,7 +50,7 @@ // JvmtiTagHashmapEntry // -// Each entry encapsulates a JNI weak reference to the tagged object +// Each entry encapsulates a reference to the tagged object // and the tag value. In addition an entry includes a next pointer which // is used to chain entries together. @@ -58,24 +58,25 @@ private: friend class JvmtiTagMap; - jweak _object; // JNI weak ref to tagged object + oop _object; // tagged object jlong _tag; // the tag JvmtiTagHashmapEntry* _next; // next on the list - inline void init(jweak object, jlong tag) { + inline void init(oop object, jlong tag) { _object = object; _tag = tag; _next = NULL; } // constructor - JvmtiTagHashmapEntry(jweak object, jlong tag) { init(object, tag); } + JvmtiTagHashmapEntry(oop object, jlong tag) { init(object, tag); } public: // accessor methods - inline jweak object() const { return _object; } - inline jlong tag() const { return _tag; } + inline oop object() const { return _object; } + inline oop* object_addr() { return &_object; } + inline jlong tag() const { return _tag; } inline void set_tag(jlong tag) { assert(tag != 0, "can't be zero"); @@ -92,9 +93,7 @@ // A hashmap is essentially a table of pointers to entries. Entries // are hashed to a location, or position in the table, and then // chained from that location. The "key" for hashing is address of -// the object, or oop. The "value" is the JNI weak reference to the -// object and the tag value. Keys are not stored with the entry. -// Instead the weak reference is resolved to obtain the key. +// the object, or oop. The "value" is the tag value. // // A hashmap maintains a count of the number entries in the hashmap // and resizes if the number of entries exceeds a given threshold. @@ -206,7 +205,7 @@ JvmtiTagHashmapEntry* entry = _table[i]; while (entry != NULL) { JvmtiTagHashmapEntry* next = entry->next(); - oop key = JNIHandles::resolve(entry->object()); + oop key = entry->object(); assert(key != NULL, "jni weak reference cleared!!"); unsigned int h = hash(key, new_size); JvmtiTagHashmapEntry* anchor = new_table[h]; @@ -299,14 +298,12 @@ unsigned int h = hash(key); JvmtiTagHashmapEntry* entry = _table[h]; while (entry != NULL) { - oop orig_key = JNIHandles::resolve(entry->object()); - assert(orig_key != NULL, "jni weak reference cleared!!"); - if (key == orig_key) { - break; + if (entry->object() == key) { + return entry; } entry = entry->next(); } - return entry; + return NULL; } @@ -343,9 +340,7 @@ JvmtiTagHashmapEntry* entry = _table[h]; JvmtiTagHashmapEntry* prev = NULL; while (entry != NULL) { - oop orig_key = JNIHandles::resolve(entry->object()); - assert(orig_key != NULL, "jni weak reference cleared!!"); - if (key == orig_key) { + if (key == entry->object()) { break; } prev = entry; @@ -418,54 +413,6 @@ } } -// memory region for young generation -MemRegion JvmtiTagMap::_young_gen; - -// get the memory region used for the young generation -void JvmtiTagMap::get_young_generation() { - CollectedHeap* ch = Universe::heap(); - switch (ch->kind()) { - case (CollectedHeap::GenCollectedHeap): { - _young_gen = ((GenCollectedHeap*)ch)->get_gen(0)->reserved(); - break; - } -#ifndef SERIALGC - case (CollectedHeap::ParallelScavengeHeap): { - _young_gen = ((ParallelScavengeHeap*)ch)->young_gen()->reserved(); - break; - } - case (CollectedHeap::G1CollectedHeap): { - // Until a more satisfactory solution is implemented, all - // oops in the tag map will require rehash at each gc. - // This is a correct, if extremely inefficient solution. - // See RFE 6621729 for related commentary. - _young_gen = ch->reserved_region(); - break; - } -#endif // !SERIALGC - default: - ShouldNotReachHere(); - } -} - -// returns true if oop is in the young generation -inline bool JvmtiTagMap::is_in_young(oop o) { - assert(_young_gen.start() != NULL, "checking"); - void* p = (void*)o; - bool in_young = _young_gen.contains(p); - return in_young; -} - -// returns the appropriate hashmap for a given object -inline JvmtiTagHashmap* JvmtiTagMap::hashmap_for(oop o) { - if (is_in_young(o)) { - return _hashmap[0]; - } else { - return _hashmap[1]; - } -} - - // create a JvmtiTagMap JvmtiTagMap::JvmtiTagMap(JvmtiEnv* env) : _env(env), @@ -476,13 +423,7 @@ assert(JvmtiThreadState_lock->is_locked(), "sanity check"); assert(((JvmtiEnvBase *)env)->tag_map() == NULL, "tag map already exists for environment"); - // create the hashmaps - for (int i=0; iset_tag_map(this); @@ -496,25 +437,20 @@ // also being destroryed. ((JvmtiEnvBase *)_env)->set_tag_map(NULL); - // iterate over the hashmaps and destroy each of the entries - for (int i=0; itable(); - for (int j=0; jsize(); j++) { - JvmtiTagHashmapEntry *entry = table[j]; - while (entry != NULL) { - JvmtiTagHashmapEntry* next = entry->next(); - jweak ref = entry->object(); - JNIHandles::destroy_weak_global(ref); - delete entry; - entry = next; - } + JvmtiTagHashmapEntry** table = _hashmap->table(); + for (int j = 0; j < _hashmap->size(); j++) { + JvmtiTagHashmapEntry* entry = table[j]; + while (entry != NULL) { + JvmtiTagHashmapEntry* next = entry->next(); + delete entry; + entry = next; } - - // finally destroy the hashmap - delete hashmap; } + // finally destroy the hashmap + delete _hashmap; + _hashmap = NULL; + // remove any entries on the free list JvmtiTagHashmapEntry* entry = _free_entries; while (entry != NULL) { @@ -522,12 +458,13 @@ delete entry; entry = next; } + _free_entries = NULL; } // create a hashmap entry // - if there's an entry on the (per-environment) free list then this // is returned. Otherwise an new entry is allocated. -JvmtiTagHashmapEntry* JvmtiTagMap::create_entry(jweak ref, jlong tag) { +JvmtiTagHashmapEntry* JvmtiTagMap::create_entry(oop ref, jlong tag) { assert(Thread::current()->is_VM_thread() || is_locked(), "checking"); JvmtiTagHashmapEntry* entry; if (_free_entries == NULL) { @@ -558,10 +495,10 @@ // returns the tag map for the given environments. If the tag map // doesn't exist then it is created. JvmtiTagMap* JvmtiTagMap::tag_map_for(JvmtiEnv* env) { - JvmtiTagMap* tag_map = ((JvmtiEnvBase *)env)->tag_map(); + JvmtiTagMap* tag_map = ((JvmtiEnvBase*)env)->tag_map(); if (tag_map == NULL) { MutexLocker mu(JvmtiThreadState_lock); - tag_map = ((JvmtiEnvBase *)env)->tag_map(); + tag_map = ((JvmtiEnvBase*)env)->tag_map(); if (tag_map == NULL) { tag_map = new JvmtiTagMap(env); } @@ -573,17 +510,13 @@ // iterate over all entries in the tag map. void JvmtiTagMap::entry_iterate(JvmtiTagHashmapEntryClosure* closure) { - for (int i=0; ientry_iterate(closure); - } + hashmap()->entry_iterate(closure); } // returns true if the hashmaps are empty bool JvmtiTagMap::is_empty() { assert(SafepointSynchronize::is_at_safepoint() || is_locked(), "checking"); - assert(n_hashmaps == 2, "not implemented"); - return ((_hashmap[0]->entry_count() == 0) && (_hashmap[1]->entry_count() == 0)); + return hashmap()->entry_count() == 0; } @@ -591,7 +524,7 @@ // not tagged // static inline jlong tag_for(JvmtiTagMap* tag_map, oop o) { - JvmtiTagHashmapEntry* entry = tag_map->hashmap_for(o)->find(o); + JvmtiTagHashmapEntry* entry = tag_map->hashmap()->find(o); if (entry == NULL) { return 0; } else { @@ -655,7 +588,7 @@ // record the context _tag_map = tag_map; - _hashmap = tag_map->hashmap_for(_o); + _hashmap = tag_map->hashmap(); _entry = _hashmap->find(_o); // get object tag @@ -694,23 +627,18 @@ if (obj_tag != 0) { // callback has tagged the object assert(Thread::current()->is_VM_thread(), "must be VMThread"); - HandleMark hm; - Handle h(o); - jweak ref = JNIHandles::make_weak_global(h); - entry = tag_map()->create_entry(ref, obj_tag); + entry = tag_map()->create_entry(o, obj_tag); hashmap->add(o, entry); } } else { // object was previously tagged - the callback may have untagged // the object or changed the tag value if (obj_tag == 0) { - jweak ref = entry->object(); JvmtiTagHashmapEntry* entry_removed = hashmap->remove(o); assert(entry_removed == entry, "checking"); tag_map()->destroy_entry(entry); - JNIHandles::destroy_weak_global(ref); } else { if (obj_tag != entry->tag()) { entry->set_tag(obj_tag); @@ -760,7 +688,7 @@ // for Classes the klassOop is tagged _referrer = klassOop_if_java_lang_Class(referrer); // record the context - _referrer_hashmap = tag_map->hashmap_for(_referrer); + _referrer_hashmap = tag_map->hashmap(); _referrer_entry = _referrer_hashmap->find(_referrer); // get object tag @@ -796,8 +724,7 @@ // // This function is performance critical. If many threads attempt to tag objects // around the same time then it's possible that the Mutex associated with the -// tag map will be a hot lock. Eliminating this lock will not eliminate the issue -// because creating a JNI weak reference requires acquiring a global lock also. +// tag map will be a hot lock. void JvmtiTagMap::set_tag(jobject object, jlong tag) { MutexLocker ml(lock()); @@ -808,22 +735,14 @@ o = klassOop_if_java_lang_Class(o); // see if the object is already tagged - JvmtiTagHashmap* hashmap = hashmap_for(o); + JvmtiTagHashmap* hashmap = _hashmap; JvmtiTagHashmapEntry* entry = hashmap->find(o); // if the object is not already tagged then we tag it if (entry == NULL) { if (tag != 0) { - HandleMark hm; - Handle h(o); - jweak ref = JNIHandles::make_weak_global(h); - - // the object may have moved because make_weak_global may - // have blocked - thus it is necessary resolve the handle - // and re-hash the object. - o = h(); - entry = create_entry(ref, tag); - hashmap_for(o)->add(o, entry); + entry = create_entry(o, tag); + hashmap->add(o, entry); } else { // no-op } @@ -831,13 +750,9 @@ // if the object is already tagged then we either update // the tag (if a new tag value has been provided) // or remove the object if the new tag value is 0. - // Removing the object requires that we also delete the JNI - // weak ref to the object. if (tag == 0) { - jweak ref = entry->object(); hashmap->remove(o); destroy_entry(entry); - JNIHandles::destroy_weak_global(ref); } else { entry->set_tag(tag); } @@ -1626,8 +1541,8 @@ void do_entry(JvmtiTagHashmapEntry* entry) { for (int i=0; i<_tag_count; i++) { if (_tags[i] == entry->tag()) { - oop o = JNIHandles::resolve(entry->object()); - assert(o != NULL && o != JNIHandles::deleted_handle(), "sanity check"); + oop o = entry->object(); + assert(o != NULL, "sanity check"); // the mirror is tagged if (o->is_klass()) { @@ -3374,62 +3289,21 @@ } -// called post-GC -// - for each JVMTI environment with an object tag map, call its rehash -// function to re-sync with the new object locations. -void JvmtiTagMap::gc_epilogue(bool full) { - assert(SafepointSynchronize::is_at_safepoint(), "must be executed at a safepoint"); +void JvmtiTagMap::weak_oops_do(BoolObjectClosure* is_alive, OopClosure* f) { + assert(SafepointSynchronize::is_at_safepoint(), + "must be executed at a safepoint"); if (JvmtiEnv::environments_might_exist()) { - // re-obtain the memory region for the young generation (might - // changed due to adaptive resizing policy) - get_young_generation(); - JvmtiEnvIterator it; for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) { JvmtiTagMap* tag_map = env->tag_map(); if (tag_map != NULL && !tag_map->is_empty()) { - TraceTime t(full ? "JVMTI Full Rehash " : "JVMTI Rehash ", TraceJVMTIObjectTagging); - if (full) { - tag_map->rehash(0, n_hashmaps); - } else { - tag_map->rehash(0, 0); // tag map for young gen only - } + tag_map->do_weak_oops(is_alive, f); } } } } -// CMS has completed referencing processing so we may have JNI weak refs -// to objects in the CMS generation that have been GC'ed. -void JvmtiTagMap::cms_ref_processing_epilogue() { - assert(SafepointSynchronize::is_at_safepoint(), "must be executed at a safepoint"); - assert(UseConcMarkSweepGC, "should only be used with CMS"); - if (JvmtiEnv::environments_might_exist()) { - JvmtiEnvIterator it; - for (JvmtiEnvBase* env = it.first(); env != NULL; env = it.next(env)) { - JvmtiTagMap* tag_map = ((JvmtiEnvBase *)env)->tag_map(); - if (tag_map != NULL && !tag_map->is_empty()) { - TraceTime t("JVMTI Rehash (CMS) ", TraceJVMTIObjectTagging); - tag_map->rehash(1, n_hashmaps); // assume CMS not used in young gen - } - } - } -} - - -// For each entry in the hashmaps 'start' to 'end' : -// -// 1. resolve the JNI weak reference -// -// 2. If it resolves to NULL it means the object has been freed so the entry -// is removed, the weak reference destroyed, and the object free event is -// posted (if enabled). -// -// 3. If the weak reference resolves to an object then we re-hash the object -// to see if it has moved or has been promoted (from the young to the old -// generation for example). -// -void JvmtiTagMap::rehash(int start, int end) { +void JvmtiTagMap::do_weak_oops(BoolObjectClosure* is_alive, OopClosure* f) { // does this environment have the OBJECT_FREE event enabled bool post_object_free = env()->is_enabled(JVMTI_EVENT_OBJECT_FREE); @@ -3437,143 +3311,98 @@ // counters used for trace message int freed = 0; int moved = 0; - int promoted = 0; - - // we assume there are two hashmaps - one for the young generation - // and the other for all other spaces. - assert(n_hashmaps == 2, "not implemented"); - JvmtiTagHashmap* young_hashmap = _hashmap[0]; - JvmtiTagHashmap* other_hashmap = _hashmap[1]; + + JvmtiTagHashmap* hashmap = this->hashmap(); // reenable sizing (if disabled) - young_hashmap->set_resizing_enabled(true); - other_hashmap->set_resizing_enabled(true); - - // when re-hashing the hashmap corresponding to the young generation we - // collect the entries corresponding to objects that have been promoted. - JvmtiTagHashmapEntry* promoted_entries = NULL; - - if (end >= n_hashmaps) { - end = n_hashmaps - 1; + hashmap->set_resizing_enabled(true); + + // if the hashmap is empty then we can skip it + if (hashmap->_entry_count == 0) { + return; } - for (int i=start; i <= end; i++) { - JvmtiTagHashmap* hashmap = _hashmap[i]; - - // if the hashmap is empty then we can skip it - if (hashmap->_entry_count == 0) { - continue; - } - - // now iterate through each entry in the table - - JvmtiTagHashmapEntry** table = hashmap->table(); - int size = hashmap->size(); - - for (int pos=0; posnext(); - - jweak ref = entry->object(); - oop oop = JNIHandles::resolve(ref); - - // has object been GC'ed - if (oop == NULL) { - // grab the tag - jlong tag = entry->tag(); - guarantee(tag != 0, "checking"); - - // remove GC'ed entry from hashmap and return the - // entry to the free list - hashmap->remove(prev, pos, entry); - destroy_entry(entry); - - // destroy the weak ref - JNIHandles::destroy_weak_global(ref); - - // post the event to the profiler - if (post_object_free) { - JvmtiExport::post_object_free(env(), tag); + // now iterate through each entry in the table + + JvmtiTagHashmapEntry** table = hashmap->table(); + int size = hashmap->size(); + + JvmtiTagHashmapEntry* delayed_add = NULL; + + for (int pos = 0; pos < size; ++pos) { + JvmtiTagHashmapEntry* entry = table[pos]; + JvmtiTagHashmapEntry* prev = NULL; + + while (entry != NULL) { + JvmtiTagHashmapEntry* next = entry->next(); + + oop* obj = entry->object_addr(); + + // has object been GC'ed + if (!is_alive->do_object_b(entry->object())) { + // grab the tag + jlong tag = entry->tag(); + guarantee(tag != 0, "checking"); + + // remove GC'ed entry from hashmap and return the + // entry to the free list + hashmap->remove(prev, pos, entry); + destroy_entry(entry); + + // post the event to the profiler + if (post_object_free) { + JvmtiExport::post_object_free(env(), tag); + } + + ++freed; + } else { + f->do_oop(entry->object_addr()); + oop new_oop = entry->object(); + + // if the object has moved then re-hash it and move its + // entry to its new location. + unsigned int new_pos = JvmtiTagHashmap::hash(new_oop, size); + if (new_pos != (unsigned int)pos) { + if (prev == NULL) { + table[pos] = next; + } else { + prev->set_next(next); } - - freed++; - entry = next; - continue; - } - - // if this is the young hashmap then the object is either promoted - // or moved. - // if this is the other hashmap then the object is moved. - - bool same_gen; - if (i == 0) { - assert(hashmap == young_hashmap, "checking"); - same_gen = is_in_young(oop); - } else { - same_gen = true; - } - - - if (same_gen) { - // if the object has moved then re-hash it and move its - // entry to its new location. - unsigned int new_pos = JvmtiTagHashmap::hash(oop, size); - if (new_pos != (unsigned int)pos) { - if (prev == NULL) { - table[pos] = next; - } else { - prev->set_next(next); - } + if (new_pos < (unsigned int)pos) { entry->set_next(table[new_pos]); table[new_pos] = entry; - moved++; } else { - // object didn't move - prev = entry; + // Delay adding this entry to it's new position as we'd end up + // hitting it again during this iteration. + entry->set_next(delayed_add); + delayed_add = entry; } + moved++; } else { - // object has been promoted so remove the entry from the - // young hashmap - assert(hashmap == young_hashmap, "checking"); - hashmap->remove(prev, pos, entry); - - // move the entry to the promoted list - entry->set_next(promoted_entries); - promoted_entries = entry; + // object didn't move + prev = entry; } - - entry = next; } + + entry = next; } } - - // add the entries, corresponding to the promoted objects, to the - // other hashmap. - JvmtiTagHashmapEntry* entry = promoted_entries; - while (entry != NULL) { - oop o = JNIHandles::resolve(entry->object()); - assert(hashmap_for(o) == other_hashmap, "checking"); - JvmtiTagHashmapEntry* next = entry->next(); - other_hashmap->add(o, entry); - entry = next; - promoted++; + // Re-add all the entries which were kept aside + while (delayed_add != NULL) { + JvmtiTagHashmapEntry* next = delayed_add->next(); + unsigned int pos = JvmtiTagHashmap::hash(delayed_add->object(), size); + delayed_add->set_next(table[pos]); + table[pos] = delayed_add; + delayed_add = next; } // stats if (TraceJVMTIObjectTagging) { - int total_moves = promoted + moved; - - int post_total = 0; - for (int i=0; i_entry_count; - } + int post_total = hashmap->_entry_count; int pre_total = post_total + freed; - tty->print("(%d->%d, %d freed, %d promoted, %d total moves)", - pre_total, post_total, freed, promoted, total_moves); + tty->print_cr("(%d->%d, %d freed, %d total moves)", + pre_total, post_total, freed, moved); } } diff -r e31d8c656c5b -r 7246a374a9f2 src/share/vm/prims/jvmtiTagMap.hpp --- a/src/share/vm/prims/jvmtiTagMap.hpp Mon Jan 10 09:23:20 2011 -0800 +++ b/src/share/vm/prims/jvmtiTagMap.hpp Mon Jan 10 17:14:53 2011 -0500 @@ -45,17 +45,12 @@ 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 @@ 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 @@ // 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 @@ 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 diff -r e31d8c656c5b -r 7246a374a9f2 src/share/vm/runtime/globals.hpp --- a/src/share/vm/runtime/globals.hpp Mon Jan 10 09:23:20 2011 -0800 +++ b/src/share/vm/runtime/globals.hpp Mon Jan 10 17:14:53 2011 -0500 @@ -1198,9 +1198,6 @@ 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. */ \ diff -r e31d8c656c5b -r 7246a374a9f2 src/share/vm/runtime/jniHandles.cpp --- a/src/share/vm/runtime/jniHandles.cpp Mon Jan 10 09:23:20 2011 -0800 +++ b/src/share/vm/runtime/jniHandles.cpp Mon Jan 10 17:14:53 2011 -0500 @@ -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 @@ 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); }