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src/share/vm/memory/genCollectedHeap.cpp
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rev 7975 : Move remaining root processing to GenCollectedHeap
@@ -24,10 +24,11 @@
#include "precompiled.hpp"
#include "classfile/symbolTable.hpp"
#include "classfile/systemDictionary.hpp"
#include "classfile/vmSymbols.hpp"
+#include "code/codeCache.hpp"
#include "code/icBuffer.hpp"
#include "gc_implementation/shared/collectorCounters.hpp"
#include "gc_implementation/shared/gcTrace.hpp"
#include "gc_implementation/shared/gcTraceTime.hpp"
#include "gc_implementation/shared/vmGCOperations.hpp"
@@ -45,10 +46,11 @@
#include "runtime/fprofiler.hpp"
#include "runtime/handles.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/java.hpp"
#include "runtime/vmThread.hpp"
+#include "services/management.hpp"
#include "services/memoryService.hpp"
#include "utilities/vmError.hpp"
#include "utilities/workgroup.hpp"
#include "utilities/macros.hpp"
#if INCLUDE_ALL_GCS
@@ -59,27 +61,31 @@
GenCollectedHeap* GenCollectedHeap::_gch;
NOT_PRODUCT(size_t GenCollectedHeap::_skip_header_HeapWords = 0;)
// The set of potentially parallel tasks in root scanning.
enum GCH_strong_roots_tasks {
- // We probably want to parallelize both of these internally, but for now...
+ GCH_PS_Universe_oops_do,
+ GCH_PS_JNIHandles_oops_do,
+ GCH_PS_ObjectSynchronizer_oops_do,
+ GCH_PS_FlatProfiler_oops_do,
+ GCH_PS_Management_oops_do,
+ GCH_PS_SystemDictionary_oops_do,
+ GCH_PS_ClassLoaderDataGraph_oops_do,
+ GCH_PS_jvmti_oops_do,
+ GCH_PS_CodeCache_oops_do,
GCH_PS_younger_gens,
// Leave this one last.
GCH_PS_NumElements
};
GenCollectedHeap::GenCollectedHeap(GenCollectorPolicy *policy) :
SharedHeap(policy),
_rem_set(NULL),
_gen_policy(policy),
- _gen_process_roots_tasks(new SubTasksDone(GCH_PS_NumElements)),
+ _process_strong_tasks(new SubTasksDone(GCH_PS_NumElements)),
_full_collections_completed(0)
{
- if (_gen_process_roots_tasks == NULL ||
- !_gen_process_roots_tasks->valid()) {
- vm_exit_during_initialization("Failed necessary allocation.");
- }
assert(policy != NULL, "Sanity check");
}
jint GenCollectedHeap::initialize() {
CollectedHeap::pre_initialize();
@@ -568,85 +574,163 @@
return collector_policy()->satisfy_failed_allocation(size, is_tlab);
}
void GenCollectedHeap::set_par_threads(uint t) {
SharedHeap::set_par_threads(t);
- _gen_process_roots_tasks->set_n_threads(t);
+ set_n_termination(t);
}
-void GenCollectedHeap::
-gen_process_roots(int level,
- bool younger_gens_as_roots,
- bool activate_scope,
- SharedHeap::ScanningOption so,
- OopsInGenClosure* not_older_gens,
- OopsInGenClosure* weak_roots,
- OopsInGenClosure* older_gens,
- CLDClosure* cld_closure,
+void GenCollectedHeap::set_n_termination(uint t) {
+ _process_strong_tasks->set_n_threads(t);
+}
+
+#ifdef ASSERT
+class AssertNonScavengableClosure: public OopClosure {
+public:
+ virtual void do_oop(oop* p) {
+ assert(!Universe::heap()->is_in_partial_collection(*p),
+ "Referent should not be scavengable."); }
+ virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
+};
+static AssertNonScavengableClosure assert_is_non_scavengable_closure;
+#endif
+
+void GenCollectedHeap::process_roots(bool activate_scope,
+ ScanningOption so,
+ OopClosure* strong_roots,
+ OopClosure* weak_roots,
+ CLDClosure* strong_cld_closure,
CLDClosure* weak_cld_closure,
- CodeBlobClosure* code_closure) {
+ CodeBlobClosure* code_roots) {
+ StrongRootsScope srs(this, activate_scope);
// General roots.
- SharedHeap::process_roots(activate_scope, so,
- not_older_gens, weak_roots,
- cld_closure, weak_cld_closure,
- code_closure);
-
- if (younger_gens_as_roots) {
- if (!_gen_process_roots_tasks->is_task_claimed(GCH_PS_younger_gens)) {
- if (level == 1) {
- not_older_gens->set_generation(_young_gen);
- _young_gen->oop_iterate(not_older_gens);
+ assert(_strong_roots_parity != 0, "must have called prologue code");
+ assert(code_roots != NULL, "code root closure should always be set");
+ // _n_termination for _process_strong_tasks should be set up stream
+ // in a method not running in a GC worker. Otherwise the GC worker
+ // could be trying to change the termination condition while the task
+ // is executing in another GC worker.
+
+ if (!_process_strong_tasks->is_task_claimed(GCH_PS_ClassLoaderDataGraph_oops_do)) {
+ ClassLoaderDataGraph::roots_cld_do(strong_cld_closure, weak_cld_closure);
+ }
+
+ // Some CLDs contained in the thread frames should be considered strong.
+ // Don't process them if they will be processed during the ClassLoaderDataGraph phase.
+ CLDClosure* roots_from_clds_p = (strong_cld_closure != weak_cld_closure) ? strong_cld_closure : NULL;
+ // Only process code roots from thread stacks if we aren't visiting the entire CodeCache anyway
+ CodeBlobClosure* roots_from_code_p = (so & SO_AllCodeCache) ? NULL : code_roots;
+
+ Threads::possibly_parallel_oops_do(strong_roots, roots_from_clds_p, roots_from_code_p);
+
+ if (!_process_strong_tasks->is_task_claimed(GCH_PS_Universe_oops_do)) {
+ Universe::oops_do(strong_roots);
+ }
+ // Global (strong) JNI handles
+ if (!_process_strong_tasks->is_task_claimed(GCH_PS_JNIHandles_oops_do))
+ JNIHandles::oops_do(strong_roots);
+
+ if (!_process_strong_tasks-> is_task_claimed(GCH_PS_ObjectSynchronizer_oops_do))
+ ObjectSynchronizer::oops_do(strong_roots);
+ if (!_process_strong_tasks->is_task_claimed(GCH_PS_FlatProfiler_oops_do))
+ FlatProfiler::oops_do(strong_roots);
+ if (!_process_strong_tasks->is_task_claimed(GCH_PS_Management_oops_do))
+ Management::oops_do(strong_roots);
+ if (!_process_strong_tasks->is_task_claimed(GCH_PS_jvmti_oops_do))
+ JvmtiExport::oops_do(strong_roots);
+
+ if (!_process_strong_tasks->is_task_claimed(GCH_PS_SystemDictionary_oops_do)) {
+ SystemDictionary::roots_oops_do(strong_roots, weak_roots);
+ }
+
+ // All threads execute the following. A specific chunk of buckets
+ // from the StringTable are the individual tasks.
+ if (weak_roots != NULL) {
+ if (CollectedHeap::use_parallel_gc_threads()) {
+ StringTable::possibly_parallel_oops_do(weak_roots);
+ } else {
+ StringTable::oops_do(weak_roots);
}
- not_older_gens->reset_generation();
}
+
+ if (!_process_strong_tasks->is_task_claimed(GCH_PS_CodeCache_oops_do)) {
+ if (so & SO_ScavengeCodeCache) {
+ assert(code_roots != NULL, "must supply closure for code cache");
+
+ // We only visit parts of the CodeCache when scavenging.
+ CodeCache::scavenge_root_nmethods_do(code_roots);
}
- // When collection is parallel, all threads get to cooperate to do
- // older-gen scanning.
- if (level == 0) {
- older_gens->set_generation(_old_gen);
- rem_set()->younger_refs_iterate(_old_gen, older_gens);
- older_gens->reset_generation();
+ if (so & SO_AllCodeCache) {
+ assert(code_roots != NULL, "must supply closure for code cache");
+
+ // CMSCollector uses this to do intermediate-strength collections.
+ // We scan the entire code cache, since CodeCache::do_unloading is not called.
+ CodeCache::blobs_do(code_roots);
+ }
+ // Verify that the code cache contents are not subject to
+ // movement by a scavenging collection.
+ DEBUG_ONLY(CodeBlobToOopClosure assert_code_is_non_scavengable(&assert_is_non_scavengable_closure, !CodeBlobToOopClosure::FixRelocations));
+ DEBUG_ONLY(CodeCache::asserted_non_scavengable_nmethods_do(&assert_code_is_non_scavengable));
}
- _gen_process_roots_tasks->all_tasks_completed();
}
-void GenCollectedHeap::
-gen_process_roots(int level,
+void GenCollectedHeap::gen_process_roots(int level,
bool younger_gens_as_roots,
bool activate_scope,
- SharedHeap::ScanningOption so,
+ ScanningOption so,
bool only_strong_roots,
OopsInGenClosure* not_older_gens,
OopsInGenClosure* older_gens,
CLDClosure* cld_closure) {
-
const bool is_adjust_phase = !only_strong_roots && !younger_gens_as_roots;
bool is_moving_collection = false;
if (level == 0 || is_adjust_phase) {
// young collections are always moving
is_moving_collection = true;
}
MarkingCodeBlobClosure mark_code_closure(not_older_gens, is_moving_collection);
- CodeBlobClosure* code_closure = &mark_code_closure;
+ OopsInGenClosure* weak_roots = only_strong_roots ? NULL : not_older_gens;
+ CLDClosure* weak_cld_closure = only_strong_roots ? NULL : cld_closure;
- gen_process_roots(level,
- younger_gens_as_roots,
- activate_scope, so,
- not_older_gens, only_strong_roots ? NULL : not_older_gens,
- older_gens,
- cld_closure, only_strong_roots ? NULL : cld_closure,
- code_closure);
+ process_roots(activate_scope, so,
+ not_older_gens, weak_roots,
+ cld_closure, weak_cld_closure,
+ &mark_code_closure);
+ if (younger_gens_as_roots) {
+ if (!_process_strong_tasks->is_task_claimed(GCH_PS_younger_gens)) {
+ if (level == 1) {
+ not_older_gens->set_generation(_young_gen);
+ _young_gen->oop_iterate(not_older_gens);
+ }
+ not_older_gens->reset_generation();
+ }
+ }
+ // When collection is parallel, all threads get to cooperate to do
+ // older-gen scanning.
+ if (level == 0) {
+ older_gens->set_generation(_old_gen);
+ rem_set()->younger_refs_iterate(_old_gen, older_gens);
+ older_gens->reset_generation();
+ }
+
+ _process_strong_tasks->all_tasks_completed();
}
+
+class AlwaysTrueClosure: public BoolObjectClosure {
+public:
+ bool do_object_b(oop p) { return true; }
+};
+static AlwaysTrueClosure always_true;
+
void GenCollectedHeap::gen_process_weak_roots(OopClosure* root_closure) {
- SharedHeap::process_weak_roots(root_closure);
- // "Local" "weak" refs
+ JNIHandles::weak_oops_do(&always_true, root_closure);
_young_gen->ref_processor()->weak_oops_do(root_closure);
_old_gen->ref_processor()->weak_oops_do(root_closure);
}
#define GCH_SINCE_SAVE_MARKS_ITERATE_DEFN(OopClosureType, nv_suffix) \
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