| /* |
| * Copyright (c) 2000, 2010, 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/fprofiler.hpp" |
| #include "runtime/java.hpp" |
| #include "services/management.hpp" |
| #include "utilities/copy.hpp" |
| #include "utilities/workgroup.hpp" |
| |
| SharedHeap* SharedHeap::_sh; |
| |
| // The set of potentially parallel tasks in strong root scanning. |
| enum SH_process_strong_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_jvmti_oops_do, |
| SH_PS_SymbolTable_oops_do, |
| SH_PS_StringTable_oops_do, |
| SH_PS_CodeCache_oops_do, |
| // Leave this one last. |
| SH_PS_NumElements |
| }; |
| |
| SharedHeap::SharedHeap(CollectorPolicy* policy_) : |
| CollectedHeap(), |
| _collector_policy(policy_), |
| _perm_gen(NULL), _rem_set(NULL), |
| _strong_roots_parity(0), |
| _process_strong_tasks(new SubTasksDone(SH_PS_NumElements)), |
| _n_par_threads(0), |
| _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 && 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(); |
| } |
| } |
| } |
| |
| 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(int t) { |
| assert(t == 0 || !UseSerialGC, "Cannot have parallel threads"); |
| _n_par_threads = t; |
| _process_strong_tasks->set_n_threads(t); |
| } |
| |
| class AssertIsPermClosure: public OopClosure { |
| public: |
| virtual void do_oop(oop* p) { |
| assert((*p) == NULL || (*p)->is_perm(), "Referent should be perm."); |
| } |
| virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); } |
| }; |
| static AssertIsPermClosure assert_is_perm_closure; |
| |
| 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) |
| : MarkScope(activate) |
| { |
| if (_active) { |
| outer->change_strong_roots_parity(); |
| } |
| } |
| |
| SharedHeap::StrongRootsScope::~StrongRootsScope() { |
| // nothing particular |
| } |
| |
| void SharedHeap::process_strong_roots(bool activate_scope, |
| bool collecting_perm_gen, |
| ScanningOption so, |
| OopClosure* roots, |
| CodeBlobClosure* code_roots, |
| OopsInGenClosure* perm_blk) { |
| StrongRootsScope srs(this, activate_scope); |
| // General strong roots. |
| assert(_strong_roots_parity != 0, "must have called prologue code"); |
| if (!_process_strong_tasks->is_task_claimed(SH_PS_Universe_oops_do)) { |
| Universe::oops_do(roots); |
| ReferenceProcessor::oops_do(roots); |
| // Consider perm-gen discovered lists to be strong. |
| perm_gen()->ref_processor()->weak_oops_do(roots); |
| } |
| // Global (strong) JNI handles |
| if (!_process_strong_tasks->is_task_claimed(SH_PS_JNIHandles_oops_do)) |
| JNIHandles::oops_do(roots); |
| // All threads execute this; the individual threads are task groups. |
| if (ParallelGCThreads > 0) { |
| Threads::possibly_parallel_oops_do(roots, code_roots); |
| } else { |
| Threads::oops_do(roots, code_roots); |
| } |
| if (!_process_strong_tasks-> is_task_claimed(SH_PS_ObjectSynchronizer_oops_do)) |
| ObjectSynchronizer::oops_do(roots); |
| if (!_process_strong_tasks->is_task_claimed(SH_PS_FlatProfiler_oops_do)) |
| FlatProfiler::oops_do(roots); |
| if (!_process_strong_tasks->is_task_claimed(SH_PS_Management_oops_do)) |
| Management::oops_do(roots); |
| if (!_process_strong_tasks->is_task_claimed(SH_PS_jvmti_oops_do)) |
| JvmtiExport::oops_do(roots); |
| |
| if (!_process_strong_tasks->is_task_claimed(SH_PS_SystemDictionary_oops_do)) { |
| if (so & SO_AllClasses) { |
| SystemDictionary::oops_do(roots); |
| } else |
| if (so & SO_SystemClasses) { |
| SystemDictionary::always_strong_oops_do(roots); |
| } |
| } |
| |
| if (!_process_strong_tasks->is_task_claimed(SH_PS_SymbolTable_oops_do)) { |
| } |
| |
| if (!_process_strong_tasks->is_task_claimed(SH_PS_StringTable_oops_do)) { |
| if (so & SO_Strings) { |
| StringTable::oops_do(roots); |
| } |
| // Verify if the string table contents are in the perm gen |
| NOT_PRODUCT(StringTable::oops_do(&assert_is_perm_closure)); |
| } |
| |
| if (!_process_strong_tasks->is_task_claimed(SH_PS_CodeCache_oops_do)) { |
| if (so & SO_CodeCache) { |
| // (Currently, CMSCollector uses this to do intermediate-strength collections.) |
| assert(collecting_perm_gen, "scanning all of code cache"); |
| assert(code_roots != NULL, "must supply closure for code cache"); |
| if (code_roots != NULL) { |
| CodeCache::blobs_do(code_roots); |
| } |
| } else if (so & (SO_SystemClasses|SO_AllClasses)) { |
| if (!collecting_perm_gen) { |
| // If we are collecting from class statics, but we are not going to |
| // visit all of the CodeCache, collect from the non-perm roots if any. |
| // This makes the code cache function temporarily as a source of strong |
| // roots for oops, until the next major collection. |
| // |
| // If collecting_perm_gen is true, we require that this phase will call |
| // CodeCache::do_unloading. This will kill off nmethods with expired |
| // weak references, such as stale invokedynamic targets. |
| CodeCache::scavenge_root_nmethods_do(code_roots); |
| } |
| } |
| // Verify if the code cache contents are in the perm gen |
| NOT_PRODUCT(CodeBlobToOopClosure assert_code_is_perm(&assert_is_perm_closure, /*do_marking=*/ false)); |
| NOT_PRODUCT(CodeCache::asserted_non_scavengable_nmethods_do(&assert_code_is_perm)); |
| } |
| |
| if (!collecting_perm_gen) { |
| // All threads perform this; coordination is handled internally. |
| |
| rem_set()->younger_refs_iterate(perm_gen(), perm_blk); |
| } |
| _process_strong_tasks->all_tasks_completed(); |
| } |
| |
| class AlwaysTrueClosure: public BoolObjectClosure { |
| public: |
| void do_object(oop p) { ShouldNotReachHere(); } |
| bool do_object_b(oop p) { return true; } |
| }; |
| static AlwaysTrueClosure always_true; |
| |
| class SkipAdjustingSharedStrings: public OopClosure { |
| OopClosure* _clo; |
| public: |
| SkipAdjustingSharedStrings(OopClosure* clo) : _clo(clo) {} |
| |
| virtual void do_oop(oop* p) { |
| oop o = (*p); |
| if (!o->is_shared_readwrite()) { |
| _clo->do_oop(p); |
| } |
| } |
| virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); } |
| }; |
| |
| // Unmarked shared Strings in the StringTable (which got there due to |
| // being in the constant pools of as-yet unloaded shared classes) were |
| // not marked and therefore did not have their mark words preserved. |
| // These entries are also deliberately not purged from the string |
| // table during unloading of unmarked strings. If an identity hash |
| // code was computed for any of these objects, it will not have been |
| // cleared to zero during the forwarding process or by the |
| // RecursiveAdjustSharedObjectClosure, and will be confused by the |
| // adjusting process as a forwarding pointer. We need to skip |
| // forwarding StringTable entries which contain unmarked shared |
| // Strings. Actually, since shared strings won't be moving, we can |
| // just skip adjusting any shared entries in the string table. |
| |
| void SharedHeap::process_weak_roots(OopClosure* root_closure, |
| CodeBlobClosure* code_roots, |
| OopClosure* non_root_closure) { |
| // Global (weak) JNI handles |
| JNIHandles::weak_oops_do(&always_true, root_closure); |
| |
| CodeCache::blobs_do(code_roots); |
| if (UseSharedSpaces && !DumpSharedSpaces) { |
| SkipAdjustingSharedStrings skip_closure(root_closure); |
| StringTable::oops_do(&skip_closure); |
| } else { |
| StringTable::oops_do(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() { |
| ref_processing_init(); |
| } |
| |
| void SharedHeap::ref_processing_init() { |
| perm_gen()->ref_processor_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)); |
| } |
