--- a/hotspot/src/share/vm/classfile/classLoaderData.cpp Fri Mar 13 09:18:28 2015 -0700
+++ b/hotspot/src/share/vm/classfile/classLoaderData.cpp Fri Mar 13 18:59:41 2015 +0000
@@ -467,6 +467,12 @@
} else {
ShouldNotReachHere();
}
+ } else {
+ // Metadata is alive.
+ // If scratch_class is on stack then it shouldn't be on this list!
+ assert(!m->is_klass() || !((InstanceKlass*)m)->is_scratch_class(),
+ "scratch classes on this list should be dead");
+ // Also should assert that other metadata on the list was found in handles.
}
}
}
@@ -737,11 +743,22 @@
// Move class loader data from main list to the unloaded list for unloading
// and deallocation later.
-bool ClassLoaderDataGraph::do_unloading(BoolObjectClosure* is_alive_closure, bool clean_alive) {
+bool ClassLoaderDataGraph::do_unloading(BoolObjectClosure* is_alive_closure,
+ bool clean_previous_versions) {
+
ClassLoaderData* data = _head;
ClassLoaderData* prev = NULL;
bool seen_dead_loader = false;
+ // Mark metadata seen on the stack only so we can delete unneeded entries.
+ // Only walk all metadata, including the expensive code cache walk, for Full GC
+ // and only if class redefinition and if there's previous versions of
+ // Klasses to delete.
+ bool walk_all_metadata = clean_previous_versions &&
+ JvmtiExport::has_redefined_a_class() &&
+ InstanceKlass::has_previous_versions();
+ MetadataOnStackMark md_on_stack(walk_all_metadata);
+
// Save previous _unloading pointer for CMS which may add to unloading list before
// purging and we don't want to rewalk the previously unloaded class loader data.
_saved_unloading = _unloading;
@@ -749,6 +766,11 @@
data = _head;
while (data != NULL) {
if (data->is_alive(is_alive_closure)) {
+ // clean metaspace
+ if (walk_all_metadata) {
+ data->classes_do(InstanceKlass::purge_previous_versions);
+ }
+ data->free_deallocate_list();
prev = data;
data = data->next();
continue;
@@ -770,11 +792,6 @@
_unloading = dead;
}
- if (clean_alive) {
- // Clean previous versions and the deallocate list.
- ClassLoaderDataGraph::clean_metaspaces();
- }
-
if (seen_dead_loader) {
post_class_unload_events();
}
@@ -782,21 +799,6 @@
return seen_dead_loader;
}
-void ClassLoaderDataGraph::clean_metaspaces() {
- // mark metadata seen on the stack and code cache so we can delete unneeded entries.
- bool has_redefined_a_class = JvmtiExport::has_redefined_a_class();
- MetadataOnStackMark md_on_stack(has_redefined_a_class);
-
- if (has_redefined_a_class) {
- for (ClassLoaderData* data = _head; data != NULL; data = data->next()) {
- data->classes_do(InstanceKlass::purge_previous_versions);
- }
- }
-
- // Should purge the previous version before deallocating.
- free_deallocate_lists();
-}
-
void ClassLoaderDataGraph::purge() {
assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint!");
ClassLoaderData* list = _unloading;
@@ -829,12 +831,6 @@
#endif
}
-void ClassLoaderDataGraph::free_deallocate_lists() {
- for (ClassLoaderData* cld = _head; cld != NULL; cld = cld->next()) {
- cld->free_deallocate_list();
- }
-}
-
// CDS support
// Global metaspaces for writing information to the shared archive. When
--- a/hotspot/src/share/vm/classfile/classLoaderData.hpp Fri Mar 13 09:18:28 2015 -0700
+++ b/hotspot/src/share/vm/classfile/classLoaderData.hpp Fri Mar 13 18:59:41 2015 +0000
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2012, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2015, 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
@@ -75,7 +75,6 @@
static ClassLoaderData* add(Handle class_loader, bool anonymous, TRAPS);
static void post_class_unload_events(void);
- static void clean_metaspaces();
public:
static ClassLoaderData* find_or_create(Handle class_loader, TRAPS);
static void purge();
@@ -95,7 +94,7 @@
static void methods_do(void f(Method*));
static void loaded_classes_do(KlassClosure* klass_closure);
static void classes_unloading_do(void f(Klass* const));
- static bool do_unloading(BoolObjectClosure* is_alive, bool clean_alive);
+ static bool do_unloading(BoolObjectClosure* is_alive, bool clean_previous_versions);
// CMS support.
static void remember_new_clds(bool remember) { _saved_head = (remember ? _head : NULL); }
@@ -114,8 +113,6 @@
static bool has_metaspace_oom() { return _metaspace_oom; }
static void set_metaspace_oom(bool value) { _metaspace_oom = value; }
- static void free_deallocate_lists();
-
static void dump_on(outputStream * const out) PRODUCT_RETURN;
static void dump() { dump_on(tty); }
static void verify();
--- a/hotspot/src/share/vm/classfile/metadataOnStackMark.cpp Fri Mar 13 09:18:28 2015 -0700
+++ b/hotspot/src/share/vm/classfile/metadataOnStackMark.cpp Fri Mar 13 18:59:41 2015 +0000
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2015, 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
@@ -33,26 +33,31 @@
#include "services/threadService.hpp"
#include "utilities/chunkedList.hpp"
-volatile MetadataOnStackBuffer* MetadataOnStackMark::_used_buffers = NULL;
-volatile MetadataOnStackBuffer* MetadataOnStackMark::_free_buffers = NULL;
+MetadataOnStackBuffer* MetadataOnStackMark::_used_buffers = NULL;
+MetadataOnStackBuffer* MetadataOnStackMark::_free_buffers = NULL;
+MetadataOnStackBuffer* MetadataOnStackMark::_current_buffer = NULL;
NOT_PRODUCT(bool MetadataOnStackMark::_is_active = false;)
// Walk metadata on the stack and mark it so that redefinition doesn't delete
-// it. Class unloading also walks the previous versions and might try to
-// delete it, so this class is used by class unloading also.
-MetadataOnStackMark::MetadataOnStackMark(bool visit_code_cache) {
+// it. Class unloading only deletes in-error class files, methods created by
+// the relocator and dummy constant pools. None of these appear anywhere except
+// in metadata Handles.
+MetadataOnStackMark::MetadataOnStackMark(bool redefinition_walk) {
assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
assert(_used_buffers == NULL, "sanity check");
+ assert(!_is_active, "MetadataOnStackMarks do not nest");
NOT_PRODUCT(_is_active = true;)
- Threads::metadata_do(Metadata::mark_on_stack);
- if (visit_code_cache) {
+ Threads::metadata_handles_do(Metadata::mark_on_stack);
+
+ if (redefinition_walk) {
+ Threads::metadata_do(Metadata::mark_on_stack);
CodeCache::alive_nmethods_do(nmethod::mark_on_stack);
+ CompileBroker::mark_on_stack();
+ JvmtiCurrentBreakpoints::metadata_do(Metadata::mark_on_stack);
+ ThreadService::metadata_do(Metadata::mark_on_stack);
}
- CompileBroker::mark_on_stack();
- JvmtiCurrentBreakpoints::metadata_do(Metadata::mark_on_stack);
- ThreadService::metadata_do(Metadata::mark_on_stack);
}
MetadataOnStackMark::~MetadataOnStackMark() {
@@ -60,10 +65,9 @@
// Unmark everything that was marked. Can't do the same walk because
// redefine classes messes up the code cache so the set of methods
// might not be the same.
+ retire_current_buffer();
- retire_buffer_for_thread(Thread::current());
-
- MetadataOnStackBuffer* buffer = const_cast<MetadataOnStackBuffer* >(_used_buffers);
+ MetadataOnStackBuffer* buffer = _used_buffers;
while (buffer != NULL) {
// Clear on stack state for all metadata.
size_t size = buffer->size();
@@ -77,7 +81,7 @@
// Move the buffer to the free list.
buffer->clear();
buffer->set_next_used(NULL);
- buffer->set_next_free(const_cast<MetadataOnStackBuffer*>(_free_buffers));
+ buffer->set_next_free(_free_buffers);
_free_buffers = buffer;
// Step to next used buffer.
@@ -93,35 +97,23 @@
if (buffer == NULL) {
return;
}
-
- MetadataOnStackBuffer* old_head;
-
- do {
- old_head = const_cast<MetadataOnStackBuffer*>(_used_buffers);
- buffer->set_next_used(old_head);
- } while (Atomic::cmpxchg_ptr(buffer, &_used_buffers, old_head) != old_head);
-}
-
-void MetadataOnStackMark::retire_buffer_for_thread(Thread* thread) {
- retire_buffer(thread->metadata_on_stack_buffer());
- thread->set_metadata_on_stack_buffer(NULL);
+ buffer->set_next_used(_used_buffers);
+ _used_buffers = buffer;
}
-bool MetadataOnStackMark::has_buffer_for_thread(Thread* thread) {
- return thread->metadata_on_stack_buffer() != NULL;
+// Current buffer is full or we're ready to walk them, add it to the used list.
+void MetadataOnStackMark::retire_current_buffer() {
+ retire_buffer(_current_buffer);
+ _current_buffer = NULL;
}
+// Get buffer off free list.
MetadataOnStackBuffer* MetadataOnStackMark::allocate_buffer() {
- MetadataOnStackBuffer* allocated;
- MetadataOnStackBuffer* new_head;
+ MetadataOnStackBuffer* allocated = _free_buffers;
- do {
- allocated = const_cast<MetadataOnStackBuffer*>(_free_buffers);
- if (allocated == NULL) {
- break;
- }
- new_head = allocated->next_free();
- } while (Atomic::cmpxchg_ptr(new_head, &_free_buffers, allocated) != allocated);
+ if (allocated != NULL) {
+ _free_buffers = allocated->next_free();
+ }
if (allocated == NULL) {
allocated = new MetadataOnStackBuffer();
@@ -133,10 +125,10 @@
}
// Record which objects are marked so we can unmark the same objects.
-void MetadataOnStackMark::record(Metadata* m, Thread* thread) {
+void MetadataOnStackMark::record(Metadata* m) {
assert(_is_active, "metadata on stack marking is active");
- MetadataOnStackBuffer* buffer = thread->metadata_on_stack_buffer();
+ MetadataOnStackBuffer* buffer = _current_buffer;
if (buffer != NULL && buffer->is_full()) {
retire_buffer(buffer);
@@ -145,7 +137,7 @@
if (buffer == NULL) {
buffer = allocate_buffer();
- thread->set_metadata_on_stack_buffer(buffer);
+ _current_buffer = buffer;
}
buffer->push(m);
--- a/hotspot/src/share/vm/classfile/metadataOnStackMark.hpp Fri Mar 13 09:18:28 2015 -0700
+++ b/hotspot/src/share/vm/classfile/metadataOnStackMark.hpp Fri Mar 13 18:59:41 2015 +0000
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2015, 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
@@ -36,23 +36,23 @@
// or executing methods, so that it can't be deleted during class redefinition
// and class unloading.
// This is also used for other things that can be deallocated, like class
-// metadata during parsing, relocated methods, and methods in backtraces.
+// metadata during parsing if errors occur, relocated methods, and temporary
+// constant pools.
class MetadataOnStackMark : public StackObj {
NOT_PRODUCT(static bool _is_active;)
-
- static volatile MetadataOnStackBuffer* _used_buffers;
- static volatile MetadataOnStackBuffer* _free_buffers;
+ static MetadataOnStackBuffer* _used_buffers;
+ static MetadataOnStackBuffer* _free_buffers;
+ static MetadataOnStackBuffer* _current_buffer;
static MetadataOnStackBuffer* allocate_buffer();
static void retire_buffer(MetadataOnStackBuffer* buffer);
public:
- MetadataOnStackMark(bool visit_code_cache);
+ MetadataOnStackMark(bool redefinition_walk);
~MetadataOnStackMark();
- static void record(Metadata* m, Thread* thread);
- static void retire_buffer_for_thread(Thread* thread);
- static bool has_buffer_for_thread(Thread* thread);
+ static void record(Metadata* m);
+ static void retire_current_buffer();
};
#endif // SHARE_VM_CLASSFILE_METADATAONSTACKMARK_HPP
--- a/hotspot/src/share/vm/classfile/systemDictionary.cpp Fri Mar 13 09:18:28 2015 -0700
+++ b/hotspot/src/share/vm/classfile/systemDictionary.cpp Fri Mar 13 18:59:41 2015 +0000
@@ -1690,9 +1690,11 @@
// Assumes classes in the SystemDictionary are only unloaded at a safepoint
// Note: anonymous classes are not in the SD.
-bool SystemDictionary::do_unloading(BoolObjectClosure* is_alive, bool clean_alive) {
+bool SystemDictionary::do_unloading(BoolObjectClosure* is_alive,
+ bool clean_previous_versions) {
// First, mark for unload all ClassLoaderData referencing a dead class loader.
- bool unloading_occurred = ClassLoaderDataGraph::do_unloading(is_alive, clean_alive);
+ bool unloading_occurred = ClassLoaderDataGraph::do_unloading(is_alive,
+ clean_previous_versions);
if (unloading_occurred) {
dictionary()->do_unloading();
constraints()->purge_loader_constraints();
--- a/hotspot/src/share/vm/classfile/systemDictionary.hpp Fri Mar 13 09:18:28 2015 -0700
+++ b/hotspot/src/share/vm/classfile/systemDictionary.hpp Fri Mar 13 18:59:41 2015 +0000
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2015, 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
@@ -335,7 +335,8 @@
// Unload (that is, break root links to) all unmarked classes and
// loaders. Returns "true" iff something was unloaded.
- static bool do_unloading(BoolObjectClosure* is_alive, bool clean_alive = true);
+ static bool do_unloading(BoolObjectClosure* is_alive,
+ bool clean_previous_versions = true);
// Used by DumpSharedSpaces only to remove classes that failed verification
static void remove_classes_in_error_state();
--- a/hotspot/src/share/vm/code/nmethod.cpp Fri Mar 13 09:18:28 2015 -0700
+++ b/hotspot/src/share/vm/code/nmethod.cpp Fri Mar 13 18:59:41 2015 +0000
@@ -1572,17 +1572,12 @@
set_unload_reported();
}
-void static clean_ic_if_metadata_is_dead(CompiledIC *ic, BoolObjectClosure *is_alive, bool mark_on_stack) {
+void static clean_ic_if_metadata_is_dead(CompiledIC *ic, BoolObjectClosure *is_alive) {
if (ic->is_icholder_call()) {
// The only exception is compiledICHolder oops which may
// yet be marked below. (We check this further below).
CompiledICHolder* cichk_oop = ic->cached_icholder();
- if (mark_on_stack) {
- Metadata::mark_on_stack(cichk_oop->holder_method());
- Metadata::mark_on_stack(cichk_oop->holder_klass());
- }
-
if (cichk_oop->holder_method()->method_holder()->is_loader_alive(is_alive) &&
cichk_oop->holder_klass()->is_loader_alive(is_alive)) {
return;
@@ -1590,10 +1585,6 @@
} else {
Metadata* ic_oop = ic->cached_metadata();
if (ic_oop != NULL) {
- if (mark_on_stack) {
- Metadata::mark_on_stack(ic_oop);
- }
-
if (ic_oop->is_klass()) {
if (((Klass*)ic_oop)->is_loader_alive(is_alive)) {
return;
@@ -1634,8 +1625,7 @@
// The RedefineClasses() API can cause the class unloading invariant
// to no longer be true. See jvmtiExport.hpp for details.
// Also, leave a debugging breadcrumb in local flag.
- bool a_class_was_redefined = JvmtiExport::has_redefined_a_class();
- if (a_class_was_redefined) {
+ if (JvmtiExport::has_redefined_a_class()) {
// This set of the unloading_occurred flag is done before the
// call to post_compiled_method_unload() so that the unloading
// of this nmethod is reported.
@@ -1654,7 +1644,7 @@
while(iter.next()) {
if (iter.type() == relocInfo::virtual_call_type) {
CompiledIC *ic = CompiledIC_at(&iter);
- clean_ic_if_metadata_is_dead(ic, is_alive, false);
+ clean_ic_if_metadata_is_dead(ic, is_alive);
}
}
}
@@ -1741,33 +1731,6 @@
return false;
}
-void nmethod::mark_metadata_on_stack_at(RelocIterator* iter_at_metadata) {
- assert(iter_at_metadata->type() == relocInfo::metadata_type, "Wrong relocation type");
-
- metadata_Relocation* r = iter_at_metadata->metadata_reloc();
- // In this metadata, we must only follow those metadatas directly embedded in
- // the code. Other metadatas (oop_index>0) are seen as part of
- // the metadata section below.
- assert(1 == (r->metadata_is_immediate()) +
- (r->metadata_addr() >= metadata_begin() && r->metadata_addr() < metadata_end()),
- "metadata must be found in exactly one place");
- if (r->metadata_is_immediate() && r->metadata_value() != NULL) {
- Metadata* md = r->metadata_value();
- if (md != _method) Metadata::mark_on_stack(md);
- }
-}
-
-void nmethod::mark_metadata_on_stack_non_relocs() {
- // Visit the metadata section
- for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {
- if (*p == Universe::non_oop_word() || *p == NULL) continue; // skip non-oops
- Metadata* md = *p;
- Metadata::mark_on_stack(md);
- }
-
- // Visit metadata not embedded in the other places.
- if (_method != NULL) Metadata::mark_on_stack(_method);
-}
bool nmethod::do_unloading_parallel(BoolObjectClosure* is_alive, bool unloading_occurred) {
ResourceMark rm;
@@ -1790,19 +1753,13 @@
// The RedefineClasses() API can cause the class unloading invariant
// to no longer be true. See jvmtiExport.hpp for details.
// Also, leave a debugging breadcrumb in local flag.
- bool a_class_was_redefined = JvmtiExport::has_redefined_a_class();
- if (a_class_was_redefined) {
+ if (JvmtiExport::has_redefined_a_class()) {
// This set of the unloading_occurred flag is done before the
// call to post_compiled_method_unload() so that the unloading
// of this nmethod is reported.
unloading_occurred = true;
}
- // When class redefinition is used all metadata in the CodeCache has to be recorded,
- // so that unused "previous versions" can be purged. Since walking the CodeCache can
- // be expensive, the "mark on stack" is piggy-backed on this parallel unloading code.
- bool mark_metadata_on_stack = a_class_was_redefined;
-
// Exception cache
clean_exception_cache(is_alive);
@@ -1818,7 +1775,7 @@
if (unloading_occurred) {
// If class unloading occurred we first iterate over all inline caches and
// clear ICs where the cached oop is referring to an unloaded klass or method.
- clean_ic_if_metadata_is_dead(CompiledIC_at(&iter), is_alive, mark_metadata_on_stack);
+ clean_ic_if_metadata_is_dead(CompiledIC_at(&iter), is_alive);
}
postponed |= clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this);
@@ -1839,16 +1796,10 @@
break;
case relocInfo::metadata_type:
- if (mark_metadata_on_stack) {
- mark_metadata_on_stack_at(&iter);
- }
+ break; // nothing to do.
}
}
- if (mark_metadata_on_stack) {
- mark_metadata_on_stack_non_relocs();
- }
-
if (is_unloaded) {
return postponed;
}
--- a/hotspot/src/share/vm/code/nmethod.hpp Fri Mar 13 09:18:28 2015 -0700
+++ b/hotspot/src/share/vm/code/nmethod.hpp Fri Mar 13 18:59:41 2015 +0000
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2015, 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
@@ -593,9 +593,6 @@
bool can_unload(BoolObjectClosure* is_alive, oop* root, bool unloading_occurred);
bool unload_if_dead_at(RelocIterator *iter_at_oop, BoolObjectClosure* is_alive, bool unloading_occurred);
- void mark_metadata_on_stack_at(RelocIterator* iter_at_metadata);
- void mark_metadata_on_stack_non_relocs();
-
public:
void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map,
OopClosure* f);
--- a/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp Fri Mar 13 09:18:28 2015 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp Fri Mar 13 18:59:41 2015 +0000
@@ -2532,11 +2532,6 @@
G1CMTraceTime trace("Unloading", G1Log::finer());
if (ClassUnloadingWithConcurrentMark) {
- // Cleaning of klasses depends on correct information from MetadataMarkOnStack. The CodeCache::mark_on_stack
- // part is too slow to be done serially, so it is handled during the weakRefsWorkParallelPart phase.
- // Defer the cleaning until we have complete on_stack data.
- MetadataOnStackMark md_on_stack(false /* Don't visit the code cache at this point */);
-
bool purged_classes;
{
@@ -2548,11 +2543,6 @@
G1CMTraceTime trace("Parallel Unloading", G1Log::finest());
weakRefsWorkParallelPart(&g1_is_alive, purged_classes);
}
-
- {
- G1CMTraceTime trace("Deallocate Metadata", G1Log::finest());
- ClassLoaderDataGraph::free_deallocate_lists();
- }
}
if (G1StringDedup::is_enabled()) {
--- a/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Fri Mar 13 09:18:28 2015 -0700
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Fri Mar 13 18:59:41 2015 +0000
@@ -4909,10 +4909,6 @@
clean_nmethod(claimed_nmethods[i]);
}
}
-
- // The nmethod cleaning helps out and does the CodeCache part of MetadataOnStackMark.
- // Need to retire the buffers now that this thread has stopped cleaning nmethods.
- MetadataOnStackMark::retire_buffer_for_thread(Thread::current());
}
void work_second_pass(uint worker_id) {
@@ -4965,9 +4961,6 @@
// G1 specific cleanup work that has
// been moved here to be done in parallel.
ik->clean_dependent_nmethods();
- if (JvmtiExport::has_redefined_a_class()) {
- InstanceKlass::purge_previous_versions(ik);
- }
}
void work() {
@@ -5002,18 +4995,8 @@
_klass_cleaning_task(is_alive) {
}
- void pre_work_verification() {
- assert(!MetadataOnStackMark::has_buffer_for_thread(Thread::current()), "Should be empty");
- }
-
- void post_work_verification() {
- assert(!MetadataOnStackMark::has_buffer_for_thread(Thread::current()), "Should be empty");
- }
-
// The parallel work done by all worker threads.
void work(uint worker_id) {
- pre_work_verification();
-
// Do first pass of code cache cleaning.
_code_cache_task.work_first_pass(worker_id);
@@ -5032,8 +5015,6 @@
// Clean all klasses that were not unloaded.
_klass_cleaning_task.work();
-
- post_work_verification();
}
};
--- a/hotspot/src/share/vm/oops/constantPool.cpp Fri Mar 13 09:18:28 2015 -0700
+++ b/hotspot/src/share/vm/oops/constantPool.cpp Fri Mar 13 18:59:41 2015 +0000
@@ -1790,17 +1790,10 @@
void ConstantPool::set_on_stack(const bool value) {
if (value) {
- int old_flags = *const_cast<volatile int *>(&_flags);
- while ((old_flags & _on_stack) == 0) {
- int new_flags = old_flags | _on_stack;
- int result = Atomic::cmpxchg(new_flags, &_flags, old_flags);
-
- if (result == old_flags) {
- // Succeeded.
- MetadataOnStackMark::record(this, Thread::current());
- return;
- }
- old_flags = result;
+ // Only record if it's not already set.
+ if (!on_stack()) {
+ _flags |= _on_stack;
+ MetadataOnStackMark::record(this);
}
} else {
// Clearing is done single-threadedly.
--- a/hotspot/src/share/vm/oops/instanceKlass.cpp Fri Mar 13 09:18:28 2015 -0700
+++ b/hotspot/src/share/vm/oops/instanceKlass.cpp Fri Mar 13 18:59:41 2015 +0000
@@ -3492,9 +3492,11 @@
#endif
+
// RedefineClasses() support for previous versions:
-
-// Purge previous versions
+int InstanceKlass::_previous_version_count = 0;
+
+// Purge previous versions before adding new previous versions of the class.
void InstanceKlass::purge_previous_versions(InstanceKlass* ik) {
if (ik->previous_versions() != NULL) {
// This klass has previous versions so see what we can cleanup
@@ -3524,6 +3526,11 @@
// are executing. Unlink this previous_version.
// The previous version InstanceKlass is on the ClassLoaderData deallocate list
// so will be deallocated during the next phase of class unloading.
+ RC_TRACE(0x00000200, ("purge: previous version " INTPTR_FORMAT " is dead",
+ pv_node));
+ // For debugging purposes.
+ pv_node->set_is_scratch_class();
+ pv_node->class_loader_data()->add_to_deallocate_list(pv_node);
pv_node = pv_node->previous_versions();
last->link_previous_versions(pv_node);
deleted_count++;
@@ -3537,7 +3544,7 @@
live_count++;
}
- // At least one method is live in this previous version so clean its MethodData.
+ // At least one method is live in this previous version.
// Reset dead EMCP methods not to get breakpoints.
// All methods are deallocated when all of the methods for this class are no
// longer running.
@@ -3561,12 +3568,6 @@
("purge: %s(%s): prev method @%d in version @%d is alive",
method->name()->as_C_string(),
method->signature()->as_C_string(), j, version));
-#ifdef ASSERT
- if (method->method_data() != NULL) {
- // Verify MethodData for running methods don't refer to old methods.
- method->method_data()->verify_clean_weak_method_links();
- }
-#endif // ASSERT
}
}
}
@@ -3579,18 +3580,6 @@
("purge: previous version stats: live=%d, deleted=%d", live_count,
deleted_count));
}
-
-#ifdef ASSERT
- // Verify clean MethodData for this class's methods, e.g. they don't refer to
- // old methods that are no longer running.
- Array<Method*>* methods = ik->methods();
- int num_methods = methods->length();
- for (int index = 0; index < num_methods; ++index) {
- if (methods->at(index)->method_data() != NULL) {
- methods->at(index)->method_data()->verify_clean_weak_method_links();
- }
- }
-#endif // ASSERT
}
void InstanceKlass::mark_newly_obsolete_methods(Array<Method*>* old_methods,
@@ -3677,6 +3666,11 @@
ConstantPool* cp_ref = scratch_class->constants();
if (!cp_ref->on_stack()) {
RC_TRACE(0x00000400, ("add: scratch class not added; no methods are running"));
+ // For debugging purposes.
+ scratch_class->set_is_scratch_class();
+ scratch_class->class_loader_data()->add_to_deallocate_list(scratch_class());
+ // Update count for class unloading.
+ _previous_version_count--;
return;
}
@@ -3688,8 +3682,8 @@
// if EMCP method (not obsolete) is on the stack, mark as EMCP so that
// we can add breakpoints for it.
- // We set the method->on_stack bit during safepoints for class redefinition and
- // class unloading and use this bit to set the is_running_emcp bit.
+ // We set the method->on_stack bit during safepoints for class redefinition
+ // and use this bit to set the is_running_emcp bit.
// After the safepoint, the on_stack bit is cleared and the running emcp
// method may exit. If so, we would set a breakpoint in a method that
// is never reached, but this won't be noticeable to the programmer.
@@ -3708,6 +3702,8 @@
assert(scratch_class->previous_versions() == NULL, "shouldn't have a previous version");
scratch_class->link_previous_versions(previous_versions());
link_previous_versions(scratch_class());
+ // Update count for class unloading.
+ _previous_version_count++;
} // end add_previous_version()
--- a/hotspot/src/share/vm/oops/instanceKlass.hpp Fri Mar 13 09:18:28 2015 -0700
+++ b/hotspot/src/share/vm/oops/instanceKlass.hpp Fri Mar 13 18:59:41 2015 +0000
@@ -206,7 +206,8 @@
_misc_is_contended = 1 << 4, // marked with contended annotation
_misc_has_default_methods = 1 << 5, // class/superclass/implemented interfaces has default methods
_misc_declares_default_methods = 1 << 6, // directly declares default methods (any access)
- _misc_has_been_redefined = 1 << 7 // class has been redefined
+ _misc_has_been_redefined = 1 << 7, // class has been redefined
+ _misc_is_scratch_class = 1 << 8 // class is the redefined scratch class
};
u2 _misc_flags;
u2 _minor_version; // minor version number of class file
@@ -626,11 +627,23 @@
_misc_flags |= _misc_has_been_redefined;
}
+ bool is_scratch_class() const {
+ return (_misc_flags & _misc_is_scratch_class) != 0;
+ }
+
+ void set_is_scratch_class() {
+ _misc_flags |= _misc_is_scratch_class;
+ }
+
void init_previous_versions() {
_previous_versions = NULL;
}
+ private:
+ static int _previous_version_count;
+ public:
static void purge_previous_versions(InstanceKlass* ik);
+ static bool has_previous_versions() { return _previous_version_count > 0; }
// JVMTI: Support for caching a class file before it is modified by an agent that can do retransformation
void set_cached_class_file(JvmtiCachedClassFileData *data) {
--- a/hotspot/src/share/vm/oops/method.cpp Fri Mar 13 09:18:28 2015 -0700
+++ b/hotspot/src/share/vm/oops/method.cpp Fri Mar 13 18:59:41 2015 +0000
@@ -1970,9 +1970,10 @@
// on stack means some method referring to it is also on the stack.
constants()->set_on_stack(value);
- bool succeeded = _access_flags.set_on_stack(value);
- if (value && succeeded) {
- MetadataOnStackMark::record(this, Thread::current());
+ bool already_set = on_stack();
+ _access_flags.set_on_stack(value);
+ if (value && !already_set) {
+ MetadataOnStackMark::record(this);
}
}
--- a/hotspot/src/share/vm/prims/jvmtiRedefineClasses.cpp Fri Mar 13 09:18:28 2015 -0700
+++ b/hotspot/src/share/vm/prims/jvmtiRedefineClasses.cpp Fri Mar 13 18:59:41 2015 +0000
@@ -142,14 +142,11 @@
for (int i = 0; i < _class_count; i++) {
redefine_single_class(_class_defs[i].klass, _scratch_classes[i], thread);
- ClassLoaderData* cld = _scratch_classes[i]->class_loader_data();
- // Free the memory for this class at class unloading time. Not before
- // because CMS might think this is still live.
- cld->add_to_deallocate_list((InstanceKlass*)_scratch_classes[i]);
- _scratch_classes[i] = NULL;
}
// Clean out MethodData pointing to old Method*
+ // Have to do this after all classes are redefined and all methods that
+ // are redefined are marked as old.
MethodDataCleaner clean_weak_method_links;
ClassLoaderDataGraph::classes_do(&clean_weak_method_links);
--- a/hotspot/src/share/vm/runtime/thread.cpp Fri Mar 13 09:18:28 2015 -0700
+++ b/hotspot/src/share/vm/runtime/thread.cpp Fri Mar 13 18:59:41 2015 +0000
@@ -203,8 +203,6 @@
// This initial value ==> never claimed.
_oops_do_parity = 0;
- _metadata_on_stack_buffer = NULL;
-
// the handle mark links itself to last_handle_mark
new HandleMark(this);
@@ -776,7 +774,8 @@
// no nmethods in a generic thread...
}
-void Thread::metadata_do(void f(Metadata*)) {
+void Thread::metadata_handles_do(void f(Metadata*)) {
+ // Only walk the Handles in Thread.
if (metadata_handles() != NULL) {
for (int i = 0; i< metadata_handles()->length(); i++) {
f(metadata_handles()->at(i));
@@ -2713,7 +2712,6 @@
}
void JavaThread::metadata_do(void f(Metadata*)) {
- Thread::metadata_do(f);
if (has_last_Java_frame()) {
// Traverse the execution stack to call f() on the methods in the stack
for (StackFrameStream fst(this); !fst.is_done(); fst.next()) {
@@ -4104,6 +4102,21 @@
}
}
+class ThreadHandlesClosure : public ThreadClosure {
+ void (*_f)(Metadata*);
+ public:
+ ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
+ virtual void do_thread(Thread* thread) {
+ thread->metadata_handles_do(_f);
+ }
+};
+
+void Threads::metadata_handles_do(void f(Metadata*)) {
+ // Only walk the Handles in Thread.
+ ThreadHandlesClosure handles_closure(f);
+ threads_do(&handles_closure);
+}
+
void Threads::deoptimized_wrt_marked_nmethods() {
ALL_JAVA_THREADS(p) {
p->deoptimized_wrt_marked_nmethods();
--- a/hotspot/src/share/vm/runtime/thread.hpp Fri Mar 13 09:18:28 2015 -0700
+++ b/hotspot/src/share/vm/runtime/thread.hpp Fri Mar 13 18:59:41 2015 +0000
@@ -255,9 +255,6 @@
jlong _allocated_bytes; // Cumulative number of bytes allocated on
// the Java heap
- // Thread-local buffer used by MetadataOnStackMark.
- MetadataOnStackBuffer* _metadata_on_stack_buffer;
-
TRACE_DATA _trace_data; // Thread-local data for tracing
ThreadExt _ext;
@@ -478,7 +475,7 @@
void nmethods_do(CodeBlobClosure* cf);
// jvmtiRedefineClasses support
- void metadata_do(void f(Metadata*));
+ void metadata_handles_do(void f(Metadata*));
// Used by fast lock support
virtual bool is_lock_owned(address adr) const;
@@ -494,9 +491,6 @@
// creation fails due to lack of memory, too many threads etc.
bool set_as_starting_thread();
- void set_metadata_on_stack_buffer(MetadataOnStackBuffer* buffer) { _metadata_on_stack_buffer = buffer; }
- MetadataOnStackBuffer* metadata_on_stack_buffer() const { return _metadata_on_stack_buffer; }
-
protected:
// OS data associated with the thread
OSThread* _osthread; // Platform-specific thread information
@@ -1915,6 +1909,7 @@
// RedefineClasses support
static void metadata_do(void f(Metadata*));
+ static void metadata_handles_do(void f(Metadata*));
#ifdef ASSERT
static bool is_vm_complete() { return _vm_complete; }
--- a/hotspot/src/share/vm/utilities/accessFlags.cpp Fri Mar 13 09:18:28 2015 -0700
+++ b/hotspot/src/share/vm/utilities/accessFlags.cpp Fri Mar 13 18:59:41 2015 +0000
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2015, 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
@@ -47,20 +47,6 @@
} while(f != old_flags);
}
-// Returns true iff this thread succeeded setting the bit.
-bool AccessFlags::atomic_set_one_bit(jint bit) {
- // Atomically update the flags with the bit given
- jint old_flags, new_flags, f;
- bool is_setting_bit = false;
- do {
- old_flags = _flags;
- new_flags = old_flags | bit;
- is_setting_bit = old_flags != new_flags;
- f = Atomic::cmpxchg(new_flags, &_flags, old_flags);
- } while(f != old_flags);
-
- return is_setting_bit;
-}
#if !defined(PRODUCT) || INCLUDE_JVMTI
--- a/hotspot/src/share/vm/utilities/accessFlags.hpp Fri Mar 13 09:18:28 2015 -0700
+++ b/hotspot/src/share/vm/utilities/accessFlags.hpp Fri Mar 13 18:59:41 2015 +0000
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2015, 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
@@ -172,7 +172,6 @@
// Atomic update of flags
void atomic_set_bits(jint bits);
- bool atomic_set_one_bit(jint bit);
void atomic_clear_bits(jint bits);
private:
@@ -234,13 +233,12 @@
atomic_set_bits(JVM_ACC_FIELD_HAS_GENERIC_SIGNATURE);
}
- bool set_on_stack(const bool value)
+ void set_on_stack(const bool value)
{
if (value) {
- return atomic_set_one_bit(JVM_ACC_ON_STACK);
+ atomic_set_bits(JVM_ACC_ON_STACK);
} else {
atomic_clear_bits(JVM_ACC_ON_STACK);
- return true; // Ignored
}
}
// Conversion