duke@435: /*
johnc@5277:  * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
stefank@2314: #include "precompiled.hpp"
stefank@2314: #include "classfile/symbolTable.hpp"
stefank@2314: #include "classfile/systemDictionary.hpp"
stefank@2314: #include "code/codeCache.hpp"
stefank@2314: #include "gc_interface/collectedHeap.inline.hpp"
stefank@2314: #include "memory/sharedHeap.hpp"
stefank@2314: #include "oops/oop.inline.hpp"
stefank@2314: #include "runtime/fprofiler.hpp"
stefank@2314: #include "runtime/java.hpp"
stefank@2314: #include "services/management.hpp"
stefank@2314: #include "utilities/copy.hpp"
stefank@2314: #include "utilities/workgroup.hpp"
duke@435: 
duke@435: SharedHeap* SharedHeap::_sh;
duke@435: 
duke@435: // The set of potentially parallel tasks in strong root scanning.
duke@435: enum SH_process_strong_roots_tasks {
duke@435:   SH_PS_Universe_oops_do,
duke@435:   SH_PS_JNIHandles_oops_do,
duke@435:   SH_PS_ObjectSynchronizer_oops_do,
duke@435:   SH_PS_FlatProfiler_oops_do,
duke@435:   SH_PS_Management_oops_do,
duke@435:   SH_PS_SystemDictionary_oops_do,
stefank@5194:   SH_PS_ClassLoaderDataGraph_oops_do,
duke@435:   SH_PS_jvmti_oops_do,
duke@435:   SH_PS_CodeCache_oops_do,
duke@435:   // Leave this one last.
duke@435:   SH_PS_NumElements
duke@435: };
duke@435: 
duke@435: SharedHeap::SharedHeap(CollectorPolicy* policy_) :
duke@435:   CollectedHeap(),
duke@435:   _collector_policy(policy_),
coleenp@4037:   _rem_set(NULL),
duke@435:   _strong_roots_parity(0),
duke@435:   _process_strong_tasks(new SubTasksDone(SH_PS_NumElements)),
jmasa@2188:   _workers(NULL)
duke@435: {
duke@435:   if (_process_strong_tasks == NULL || !_process_strong_tasks->valid()) {
duke@435:     vm_exit_during_initialization("Failed necessary allocation.");
duke@435:   }
duke@435:   _sh = this;  // ch is static, should be set only once.
duke@435:   if ((UseParNewGC ||
ysr@777:       (UseConcMarkSweepGC && CMSParallelRemarkEnabled) ||
ysr@777:        UseG1GC) &&
duke@435:       ParallelGCThreads > 0) {
jmasa@2188:     _workers = new FlexibleWorkGang("Parallel GC Threads", ParallelGCThreads,
ysr@777:                             /* are_GC_task_threads */true,
ysr@777:                             /* are_ConcurrentGC_threads */false);
duke@435:     if (_workers == NULL) {
duke@435:       vm_exit_during_initialization("Failed necessary allocation.");
jmasa@2188:     } else {
jmasa@2188:       _workers->initialize_workers();
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
jmasa@3294: int SharedHeap::n_termination() {
jmasa@3294:   return _process_strong_tasks->n_threads();
jmasa@3294: }
jmasa@3294: 
jmasa@3294: void SharedHeap::set_n_termination(int t) {
jmasa@3294:   _process_strong_tasks->set_n_threads(t);
jmasa@3294: }
jmasa@3294: 
ysr@777: bool SharedHeap::heap_lock_held_for_gc() {
ysr@777:   Thread* t = Thread::current();
ysr@777:   return    Heap_lock->owned_by_self()
ysr@777:          || (   (t->is_GC_task_thread() ||  t->is_VM_thread())
ysr@777:              && _thread_holds_heap_lock_for_gc);
ysr@777: }
duke@435: 
jmasa@3357: void SharedHeap::set_par_threads(uint t) {
jmasa@2188:   assert(t == 0 || !UseSerialGC, "Cannot have parallel threads");
duke@435:   _n_par_threads = t;
jmasa@2188:   _process_strong_tasks->set_n_threads(t);
duke@435: }
duke@435: 
jmasa@2909: #ifdef ASSERT
jmasa@2909: class AssertNonScavengableClosure: public OopClosure {
jmasa@2909: public:
jmasa@2909:   virtual void do_oop(oop* p) {
jmasa@2909:     assert(!Universe::heap()->is_in_partial_collection(*p),
jmasa@2909:       "Referent should not be scavengable.");  }
jmasa@2909:   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
jmasa@2909: };
jmasa@2909: static AssertNonScavengableClosure assert_is_non_scavengable_closure;
jmasa@2909: #endif
jmasa@2909: 
duke@435: void SharedHeap::change_strong_roots_parity() {
duke@435:   // Also set the new collection parity.
duke@435:   assert(_strong_roots_parity >= 0 && _strong_roots_parity <= 2,
duke@435:          "Not in range.");
duke@435:   _strong_roots_parity++;
duke@435:   if (_strong_roots_parity == 3) _strong_roots_parity = 1;
duke@435:   assert(_strong_roots_parity >= 1 && _strong_roots_parity <= 2,
duke@435:          "Not in range.");
duke@435: }
duke@435: 
jrose@1424: SharedHeap::StrongRootsScope::StrongRootsScope(SharedHeap* outer, bool activate)
jrose@1424:   : MarkScope(activate)
jrose@1424: {
jrose@1424:   if (_active) {
jrose@1424:     outer->change_strong_roots_parity();
johnc@5277:     // Zero the claimed high water mark in the StringTable
johnc@5277:     StringTable::clear_parallel_claimed_index();
jrose@1424:   }
jrose@1424: }
jrose@1424: 
jrose@1424: SharedHeap::StrongRootsScope::~StrongRootsScope() {
jrose@1424:   // nothing particular
jrose@1424: }
jrose@1424: 
jrose@1424: void SharedHeap::process_strong_roots(bool activate_scope,
coleenp@4037:                                       bool is_scavenging,
duke@435:                                       ScanningOption so,
duke@435:                                       OopClosure* roots,
jrose@1424:                                       CodeBlobClosure* code_roots,
coleenp@4037:                                       KlassClosure* klass_closure) {
jrose@1424:   StrongRootsScope srs(this, activate_scope);
coleenp@4037: 
duke@435:   // General strong roots.
jrose@1424:   assert(_strong_roots_parity != 0, "must have called prologue code");
jmasa@3294:   // _n_termination for _process_strong_tasks should be set up stream
jmasa@3294:   // in a method not running in a GC worker.  Otherwise the GC worker
jmasa@3294:   // could be trying to change the termination condition while the task
jmasa@3294:   // is executing in another GC worker.
duke@435:   if (!_process_strong_tasks->is_task_claimed(SH_PS_Universe_oops_do)) {
duke@435:     Universe::oops_do(roots);
duke@435:   }
duke@435:   // Global (strong) JNI handles
duke@435:   if (!_process_strong_tasks->is_task_claimed(SH_PS_JNIHandles_oops_do))
duke@435:     JNIHandles::oops_do(roots);
johnc@5277: 
duke@435:   // All threads execute this; the individual threads are task groups.
stefank@4298:   CLDToOopClosure roots_from_clds(roots);
stefank@4298:   CLDToOopClosure* roots_from_clds_p = (is_scavenging ? NULL : &roots_from_clds);
johnc@5277:   if (CollectedHeap::use_parallel_gc_threads()) {
johnc@5277:     Threads::possibly_parallel_oops_do(roots, roots_from_clds_p, code_roots);
duke@435:   } else {
stefank@4298:     Threads::oops_do(roots, roots_from_clds_p, code_roots);
duke@435:   }
johnc@5277: 
duke@435:   if (!_process_strong_tasks-> is_task_claimed(SH_PS_ObjectSynchronizer_oops_do))
duke@435:     ObjectSynchronizer::oops_do(roots);
duke@435:   if (!_process_strong_tasks->is_task_claimed(SH_PS_FlatProfiler_oops_do))
duke@435:     FlatProfiler::oops_do(roots);
duke@435:   if (!_process_strong_tasks->is_task_claimed(SH_PS_Management_oops_do))
duke@435:     Management::oops_do(roots);
duke@435:   if (!_process_strong_tasks->is_task_claimed(SH_PS_jvmti_oops_do))
duke@435:     JvmtiExport::oops_do(roots);
duke@435: 
duke@435:   if (!_process_strong_tasks->is_task_claimed(SH_PS_SystemDictionary_oops_do)) {
duke@435:     if (so & SO_AllClasses) {
duke@435:       SystemDictionary::oops_do(roots);
stefank@5194:     } else if (so & SO_SystemClasses) {
stefank@5194:       SystemDictionary::always_strong_oops_do(roots);
stefank@5194:     } else {
stefank@5194:       fatal("We should always have selected either SO_AllClasses or SO_SystemClasses");
stefank@5194:     }
stefank@5194:   }
stefank@5194: 
stefank@5194:   if (!_process_strong_tasks->is_task_claimed(SH_PS_ClassLoaderDataGraph_oops_do)) {
stefank@5194:     if (so & SO_AllClasses) {
coleenp@4037:       ClassLoaderDataGraph::oops_do(roots, klass_closure, !is_scavenging);
ysr@2825:     } else if (so & SO_SystemClasses) {
coleenp@4037:       ClassLoaderDataGraph::always_strong_oops_do(roots, klass_closure, !is_scavenging);
ysr@2825:     }
duke@435:   }
duke@435: 
johnc@5277:   // All threads execute the following. A specific chunk of buckets
johnc@5277:   // from the StringTable are the individual tasks.
johnc@5277:   if (so & SO_Strings) {
johnc@5277:     if (CollectedHeap::use_parallel_gc_threads()) {
johnc@5277:       StringTable::possibly_parallel_oops_do(roots);
johnc@5277:     } else {
jcoomes@2661:       StringTable::oops_do(roots);
jcoomes@2661:     }
duke@435:   }
duke@435: 
duke@435:   if (!_process_strong_tasks->is_task_claimed(SH_PS_CodeCache_oops_do)) {
jrose@1424:     if (so & SO_CodeCache) {
jrose@1424:       assert(code_roots != NULL, "must supply closure for code cache");
coleenp@4037: 
coleenp@4037:       if (is_scavenging) {
coleenp@4037:         // We only visit parts of the CodeCache when scavenging.
coleenp@4037:         CodeCache::scavenge_root_nmethods_do(code_roots);
coleenp@4037:       } else {
coleenp@4037:         // CMSCollector uses this to do intermediate-strength collections.
coleenp@4037:         // We scan the entire code cache, since CodeCache::do_unloading is not called.
jrose@1424:         CodeCache::blobs_do(code_roots);
jrose@1424:       }
jrose@1424:     }
jmasa@2909:     // Verify that the code cache contents are not subject to
jmasa@2909:     // movement by a scavenging collection.
jmasa@2909:     DEBUG_ONLY(CodeBlobToOopClosure assert_code_is_non_scavengable(&assert_is_non_scavengable_closure, /*do_marking=*/ false));
jmasa@2909:     DEBUG_ONLY(CodeCache::asserted_non_scavengable_nmethods_do(&assert_code_is_non_scavengable));
duke@435:   }
duke@435: 
duke@435:   _process_strong_tasks->all_tasks_completed();
duke@435: }
duke@435: 
duke@435: class AlwaysTrueClosure: public BoolObjectClosure {
duke@435: public:
duke@435:   bool do_object_b(oop p) { return true; }
duke@435: };
duke@435: static AlwaysTrueClosure always_true;
duke@435: 
duke@435: void SharedHeap::process_weak_roots(OopClosure* root_closure,
stefank@5011:                                     CodeBlobClosure* code_roots) {
duke@435:   // Global (weak) JNI handles
duke@435:   JNIHandles::weak_oops_do(&always_true, root_closure);
duke@435: 
jrose@1424:   CodeCache::blobs_do(code_roots);
stefank@5011:   StringTable::oops_do(root_closure);
stefank@5011: }
duke@435: 
duke@435: void SharedHeap::set_barrier_set(BarrierSet* bs) {
duke@435:   _barrier_set = bs;
duke@435:   // Cached barrier set for fast access in oops
duke@435:   oopDesc::set_bs(bs);
duke@435: }
duke@435: 
duke@435: void SharedHeap::post_initialize() {
duke@435:   ref_processing_init();
duke@435: }
duke@435: 
coleenp@4037: void SharedHeap::ref_processing_init() {}
duke@435: 
duke@435: // Some utilities.
ysr@777: void SharedHeap::print_size_transition(outputStream* out,
ysr@777:                                        size_t bytes_before,
duke@435:                                        size_t bytes_after,
duke@435:                                        size_t capacity) {
ysr@777:   out->print(" %d%s->%d%s(%d%s)",
duke@435:              byte_size_in_proper_unit(bytes_before),
duke@435:              proper_unit_for_byte_size(bytes_before),
duke@435:              byte_size_in_proper_unit(bytes_after),
duke@435:              proper_unit_for_byte_size(bytes_after),
duke@435:              byte_size_in_proper_unit(capacity),
duke@435:              proper_unit_for_byte_size(capacity));
duke@435: }