Mercurial > hg > truffle
view src/share/vm/memory/sharedHeap.cpp @ 21863:f4822d122041 jdk8u45-b11
Merge
author | asaha |
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date | Sat, 07 Mar 2015 16:26:10 -0800 |
parents | f3aeae1f9fc5 |
children | 7848fc12602b |
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/* * Copyright (c) 2000, 2014, 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 * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "classfile/symbolTable.hpp" #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 root scanning. 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, SH_PS_SystemDictionary_oops_do, SH_PS_ClassLoaderDataGraph_oops_do, SH_PS_jvmti_oops_do, SH_PS_CodeCache_oops_do, // Leave this one last. SH_PS_NumElements }; 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()) { vm_exit_during_initialization("Failed necessary allocation."); } _sh = this; // ch is static, should be set only once. if ((UseParNewGC || (UseConcMarkSweepGC && (CMSParallelInitialMarkEnabled || CMSParallelRemarkEnabled)) || UseG1GC) && ParallelGCThreads > 0) { _workers = new FlexibleWorkGang("Parallel GC Threads", ParallelGCThreads, /* are_GC_task_threads */true, /* are_ConcurrentGC_threads */false); if (_workers == NULL) { vm_exit_during_initialization("Failed necessary allocation."); } else { _workers->initialize_workers(); } } } int SharedHeap::n_termination() { return _process_strong_tasks->n_threads(); } void SharedHeap::set_n_termination(int t) { _process_strong_tasks->set_n_threads(t); } bool SharedHeap::heap_lock_held_for_gc() { Thread* t = Thread::current(); return Heap_lock->owned_by_self() || ( (t->is_GC_task_thread() || t->is_VM_thread()) && _thread_holds_heap_lock_for_gc); } void SharedHeap::set_par_threads(uint t) { assert(t == 0 || !UseSerialGC, "Cannot have parallel threads"); _n_par_threads = 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 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* heap, bool activate) : MarkScope(activate), _sh(heap), _n_workers_done_with_threads(0) { if (_active) { _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() { if (_active) { _sh->unregister_strong_roots_scope(this); } } Monitor* SharedHeap::StrongRootsScope::_lock = new Monitor(Mutex::leaf, "StrongRootsScope lock", false); void SharedHeap::StrongRootsScope::mark_worker_done_with_threads(uint n_workers) { // The Thread work barrier is only needed by G1 Class Unloading. // No need to use the barrier if this is single-threaded code. if (UseG1GC && ClassUnloadingWithConcurrentMark && 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) { assert(UseG1GC, "Currently only used by G1"); assert(ClassUnloadingWithConcurrentMark, "Currently only needed when doing G1 Class Unloading"); // 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 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(strong_roots); } // Global (strong) JNI handles if (!_process_strong_tasks->is_task_claimed(SH_PS_JNIHandles_oops_do)) JNIHandles::oops_do(strong_roots); if (!_process_strong_tasks-> is_task_claimed(SH_PS_ObjectSynchronizer_oops_do)) ObjectSynchronizer::oops_do(strong_roots); if (!_process_strong_tasks->is_task_claimed(SH_PS_FlatProfiler_oops_do)) FlatProfiler::oops_do(strong_roots); if (!_process_strong_tasks->is_task_claimed(SH_PS_Management_oops_do)) Management::oops_do(strong_roots); if (!_process_strong_tasks->is_task_claimed(SH_PS_jvmti_oops_do)) JvmtiExport::oops_do(strong_roots); if (!_process_strong_tasks->is_task_claimed(SH_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); } } 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"); // We only visit parts of the CodeCache when scavenging. CodeCache::scavenge_root_nmethods_do(code_roots); } 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)); } _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; } }; static AlwaysTrueClosure always_true; void SharedHeap::process_weak_roots(OopClosure* root_closure) { // Global (weak) JNI handles JNIHandles::weak_oops_do(&always_true, root_closure); } void SharedHeap::set_barrier_set(BarrierSet* bs) { _barrier_set = bs; // Cached barrier set for fast access in oops oopDesc::set_bs(bs); } void SharedHeap::post_initialize() { CollectedHeap::post_initialize(); ref_processing_init(); } void SharedHeap::ref_processing_init() {} // Some utilities. void SharedHeap::print_size_transition(outputStream* out, size_t bytes_before, size_t bytes_after, size_t capacity) { out->print(" %d%s->%d%s(%d%s)", byte_size_in_proper_unit(bytes_before), proper_unit_for_byte_size(bytes_before), byte_size_in_proper_unit(bytes_after), proper_unit_for_byte_size(bytes_after), byte_size_in_proper_unit(capacity), proper_unit_for_byte_size(capacity)); }