jdk-sandbox: comparison hotspot/src/share/vm/memory/sharedHeap.cpp

equal deleted inserted replaced

-:70fb742e40aa
+:d27050bdfb04
 #include "classfile/systemDictionary.hpp"
 #include "code/codeCache.hpp"
 #include "gc_interface/collectedHeap.inline.hpp"
 #include "memory/sharedHeap.hpp"
 #include "oops/oop.inline.hpp"
+#include "runtime/atomic.inline.hpp"
 #include "runtime/fprofiler.hpp"
 #include "runtime/java.hpp"
 #include "services/management.hpp"
 #include "utilities/copy.hpp"
 #include "utilities/workgroup.hpp"
 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
 SharedHeap* SharedHeap::_sh;
-// The set of potentially parallel tasks in strong root scanning.
+// The set of potentially parallel tasks in root scanning.
-enum SH_process_strong_roots_tasks {
+enum SH_process_roots_tasks {
 SH_PS_Universe_oops_do,
 SH_PS_JNIHandles_oops_do,
 SH_PS_ObjectSynchronizer_oops_do,
 SH_PS_FlatProfiler_oops_do,
 SH_PS_Management_oops_do,
 SharedHeap::SharedHeap(CollectorPolicy* policy_) :
 CollectedHeap(),
 _collector_policy(policy_),
 _rem_set(NULL),
+_strong_roots_scope(NULL),
 _strong_roots_parity(0),
 _process_strong_tasks(new SubTasksDone(SH_PS_NumElements)),
 _workers(NULL)
 {
 if (_process_strong_tasks == NULL || !_process_strong_tasks->valid()) {
 virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
 };
 static AssertNonScavengableClosure assert_is_non_scavengable_closure;
 #endif
+SharedHeap::StrongRootsScope* SharedHeap::active_strong_roots_scope() const {
+return _strong_roots_scope;
+}
+void SharedHeap::register_strong_roots_scope(SharedHeap::StrongRootsScope* scope) {
+assert(_strong_roots_scope == NULL, "Should only have one StrongRootsScope active");
+assert(scope != NULL, "Illegal argument");
+_strong_roots_scope = scope;
+}
+void SharedHeap::unregister_strong_roots_scope(SharedHeap::StrongRootsScope* scope) {
+assert(_strong_roots_scope == scope, "Wrong scope unregistered");
+_strong_roots_scope = NULL;
+}
 void SharedHeap::change_strong_roots_parity() {
 // Also set the new collection parity.
 assert(_strong_roots_parity >= 0 && _strong_roots_parity <= 2,
 "Not in range.");
 _strong_roots_parity++;
 if (_strong_roots_parity == 3) _strong_roots_parity = 1;
 assert(_strong_roots_parity >= 1 && _strong_roots_parity <= 2,
 "Not in range.");
 }
-SharedHeap::StrongRootsScope::StrongRootsScope(SharedHeap* outer, bool activate)
+SharedHeap::StrongRootsScope::StrongRootsScope(SharedHeap* heap, bool activate)
-: MarkScope(activate)
+: MarkScope(activate), _sh(heap), _n_workers_done_with_threads(0)
 {
 if (_active) {
-outer->change_strong_roots_parity();
+_sh->register_strong_roots_scope(this);
+_sh->change_strong_roots_parity();
 // Zero the claimed high water mark in the StringTable
 StringTable::clear_parallel_claimed_index();
 }
 }
 SharedHeap::StrongRootsScope::~StrongRootsScope() {
-// nothing particular
+if (_active) {
-}
+_sh->unregister_strong_roots_scope(this);
+}
-void SharedHeap::process_strong_roots(bool activate_scope,
+}
-ScanningOption so,
-OopClosure* roots,
+Monitor* SharedHeap::StrongRootsScope::_lock = new Monitor(Mutex::leaf, "StrongRootsScope lock", false);
-KlassClosure* klass_closure) {
+void SharedHeap::StrongRootsScope::mark_worker_done_with_threads(uint n_workers) {
+// The Thread work barrier is only needed by G1.
+// No need to use the barrier if this is single-threaded code.
+if (UseG1GC && n_workers > 0) {
+uint new_value = (uint)Atomic::add(1, &_n_workers_done_with_threads);
+if (new_value == n_workers) {
+// This thread is last. Notify the others.
+MonitorLockerEx ml(_lock, Mutex::_no_safepoint_check_flag);
+_lock->notify_all();
+}
+}
+}
+void SharedHeap::StrongRootsScope::wait_until_all_workers_done_with_threads(uint n_workers) {
+// No need to use the barrier if this is single-threaded code.
+if (n_workers > 0 && (uint)_n_workers_done_with_threads != n_workers) {
+MonitorLockerEx ml(_lock, Mutex::_no_safepoint_check_flag);
+while ((uint)_n_workers_done_with_threads != n_workers) {
+_lock->wait(Mutex::_no_safepoint_check_flag, 0, false);
+}
+}
+}
+void SharedHeap::process_roots(bool activate_scope,
+ScanningOption so,
+OopClosure* strong_roots,
+OopClosure* weak_roots,
+CLDClosure* strong_cld_closure,
+CLDClosure* weak_cld_closure,
+CodeBlobClosure* code_roots) {
 StrongRootsScope srs(this, activate_scope);
-// General strong roots.
+// General roots.
 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.
+// Iterating over the CLDG and the Threads are done early to allow G1 to
+// first process the strong CLDs and nmethods and then, after a barrier,
+// let the thread process the weak CLDs and nmethods.
+if (!_process_strong_tasks->is_task_claimed(SH_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);
+// This is the point where this worker thread will not find more strong CLDs/nmethods.
+// Report this so G1 can synchronize the strong and weak CLDs/nmethods processing.
+active_strong_roots_scope()->mark_worker_done_with_threads(n_par_threads());
 if (!_process_strong_tasks->is_task_claimed(SH_PS_Universe_oops_do)) {
-Universe::oops_do(roots);
+Universe::oops_do(strong_roots);
 }
 // Global (strong) JNI handles
 if (!_process_strong_tasks->is_task_claimed(SH_PS_JNIHandles_oops_do))
-JNIHandles::oops_do(roots);
+JNIHandles::oops_do(strong_roots);
-CodeBlobToOopClosure code_roots(roots, true);
-CLDToOopClosure roots_from_clds(roots);
-// If we limit class scanning to SO_SystemClasses we need to apply a CLD closure to
-// CLDs which are strongly reachable from the thread stacks.
-CLDToOopClosure* roots_from_clds_p = ((so & SO_SystemClasses) ? &roots_from_clds : NULL);
-// All threads execute this; the individual threads are task groups.
-if (CollectedHeap::use_parallel_gc_threads()) {
-Threads::possibly_parallel_oops_do(roots, roots_from_clds_p, &code_roots);
-} else {
-Threads::oops_do(roots, roots_from_clds_p, &code_roots);
-}
 if (!_process_strong_tasks-> is_task_claimed(SH_PS_ObjectSynchronizer_oops_do))
-ObjectSynchronizer::oops_do(roots);
+ObjectSynchronizer::oops_do(strong_roots);
 if (!_process_strong_tasks->is_task_claimed(SH_PS_FlatProfiler_oops_do))
-FlatProfiler::oops_do(roots);
+FlatProfiler::oops_do(strong_roots);
 if (!_process_strong_tasks->is_task_claimed(SH_PS_Management_oops_do))
-Management::oops_do(roots);
+Management::oops_do(strong_roots);
 if (!_process_strong_tasks->is_task_claimed(SH_PS_jvmti_oops_do))
-JvmtiExport::oops_do(roots);
+JvmtiExport::oops_do(strong_roots);
 if (!_process_strong_tasks->is_task_claimed(SH_PS_SystemDictionary_oops_do)) {
-if (so & SO_AllClasses) {
+SystemDictionary::roots_oops_do(strong_roots, weak_roots);
-SystemDictionary::oops_do(roots);
-} else if (so & SO_SystemClasses) {
-SystemDictionary::always_strong_oops_do(roots);
-} else {
-fatal("We should always have selected either SO_AllClasses or SO_SystemClasses");
-}
-}
-if (!_process_strong_tasks->is_task_claimed(SH_PS_ClassLoaderDataGraph_oops_do)) {
-if (so & SO_AllClasses) {
-ClassLoaderDataGraph::oops_do(roots, klass_closure, /* must_claim */ false);
-} else if (so & SO_SystemClasses) {
-ClassLoaderDataGraph::always_strong_oops_do(roots, klass_closure, /* must_claim */ true);
-}
 }
 // All threads execute the following. A specific chunk of buckets
 // from the StringTable are the individual tasks.
-if (so & SO_Strings) {
+if (weak_roots != NULL) {
 if (CollectedHeap::use_parallel_gc_threads()) {
-StringTable::possibly_parallel_oops_do(roots);
+StringTable::possibly_parallel_oops_do(weak_roots);
 } else {
-StringTable::oops_do(roots);
+StringTable::oops_do(weak_roots);
 }
 }
 if (!_process_strong_tasks->is_task_claimed(SH_PS_CodeCache_oops_do)) {
 if (so & SO_ScavengeCodeCache) {
-assert(&code_roots != NULL, "must supply closure for code cache");
+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);
+CodeCache::scavenge_root_nmethods_do(code_roots);
 }
 if (so & SO_AllCodeCache) {
-assert(&code_roots != NULL, "must supply closure for code cache");
+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);
+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, /*do_marking=*/ false));
+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));
 }
 _process_strong_tasks->all_tasks_completed();
 }
+void SharedHeap::process_all_roots(bool activate_scope,
+ScanningOption so,
+OopClosure* roots,
+CLDClosure* cld_closure,
+CodeBlobClosure* code_closure) {
+process_roots(activate_scope, so,
+roots, roots,
+cld_closure, cld_closure,
+code_closure);
+}
+void SharedHeap::process_strong_roots(bool activate_scope,
+ScanningOption so,
+OopClosure* roots,
+CLDClosure* cld_closure,
+CodeBlobClosure* code_closure) {
+process_roots(activate_scope, so,
+roots, NULL,
+cld_closure, NULL,
+code_closure);
+}
 class AlwaysTrueClosure: public BoolObjectClosure {
 public:
 bool do_object_b(oop p) { return true; }
 };

changeset 25492	d27050bdfb04
parent 25491	70fb742e40aa
child 25908	8adb2fb6fc3c