| /* |
| * 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/stringTable.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(" " SIZE_FORMAT "%s->" SIZE_FORMAT "%s(" SIZE_FORMAT "%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)); |
| } |
