duke@435: /*
xdono@631:  * Copyright 2005-2008 Sun Microsystems, Inc.  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:  *
duke@435:  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435:  * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435:  * have any questions.
duke@435:  *
duke@435:  */
duke@435: # include "incls/_precompiled.incl"
duke@435: # include "incls/_vmGCOperations.cpp.incl"
duke@435: 
duke@435: HS_DTRACE_PROBE_DECL1(hotspot, gc__begin, bool);
duke@435: HS_DTRACE_PROBE_DECL(hotspot, gc__end);
duke@435: 
duke@435: // The same dtrace probe can't be inserted in two different files, so we
duke@435: // have to call it here, so it's only in one file.  Can't create new probes
duke@435: // for the other file anymore.   The dtrace probes have to remain stable.
duke@435: void VM_GC_Operation::notify_gc_begin(bool full) {
duke@435:   HS_DTRACE_PROBE1(hotspot, gc__begin, full);
duke@435: }
duke@435: 
duke@435: void VM_GC_Operation::notify_gc_end() {
duke@435:   HS_DTRACE_PROBE(hotspot, gc__end);
duke@435: }
duke@435: 
duke@435: void VM_GC_Operation::acquire_pending_list_lock() {
duke@435:   // we may enter this with pending exception set
duke@435:   instanceRefKlass::acquire_pending_list_lock(&_pending_list_basic_lock);
duke@435: }
duke@435: 
duke@435: 
duke@435: void VM_GC_Operation::release_and_notify_pending_list_lock() {
duke@435: 
duke@435:   instanceRefKlass::release_and_notify_pending_list_lock(&_pending_list_basic_lock);
duke@435: }
duke@435: 
duke@435: // Allocations may fail in several threads at about the same time,
duke@435: // resulting in multiple gc requests.  We only want to do one of them.
duke@435: // In case a GC locker is active and the need for a GC is already signalled,
duke@435: // we want to skip this GC attempt altogether, without doing a futile
duke@435: // safepoint operation.
duke@435: bool VM_GC_Operation::skip_operation() const {
duke@435:   bool skip = (_gc_count_before != Universe::heap()->total_collections());
duke@435:   if (_full && skip) {
duke@435:     skip = (_full_gc_count_before != Universe::heap()->total_full_collections());
duke@435:   }
duke@435:   if (!skip && GC_locker::is_active_and_needs_gc()) {
duke@435:     skip = Universe::heap()->is_maximal_no_gc();
duke@435:     assert(!(skip && (_gc_cause == GCCause::_gc_locker)),
duke@435:            "GC_locker cannot be active when initiating GC");
duke@435:   }
duke@435:   return skip;
duke@435: }
duke@435: 
duke@435: bool VM_GC_Operation::doit_prologue() {
duke@435:   assert(Thread::current()->is_Java_thread(), "just checking");
duke@435: 
duke@435:   acquire_pending_list_lock();
duke@435:   // If the GC count has changed someone beat us to the collection
duke@435:   // Get the Heap_lock after the pending_list_lock.
duke@435:   Heap_lock->lock();
ysr@777: 
duke@435:   // Check invocations
duke@435:   if (skip_operation()) {
duke@435:     // skip collection
duke@435:     Heap_lock->unlock();
duke@435:     release_and_notify_pending_list_lock();
duke@435:     _prologue_succeeded = false;
duke@435:   } else {
duke@435:     _prologue_succeeded = true;
ysr@777:     SharedHeap* sh = SharedHeap::heap();
ysr@777:     if (sh != NULL) sh->_thread_holds_heap_lock_for_gc = true;
duke@435:   }
duke@435:   return _prologue_succeeded;
duke@435: }
duke@435: 
duke@435: 
duke@435: void VM_GC_Operation::doit_epilogue() {
duke@435:   assert(Thread::current()->is_Java_thread(), "just checking");
duke@435:   // Release the Heap_lock first.
ysr@777:   SharedHeap* sh = SharedHeap::heap();
ysr@777:   if (sh != NULL) sh->_thread_holds_heap_lock_for_gc = false;
duke@435:   Heap_lock->unlock();
duke@435:   release_and_notify_pending_list_lock();
duke@435: }
duke@435: 
duke@435: bool VM_GC_HeapInspection::doit_prologue() {
duke@435:   if (Universe::heap()->supports_heap_inspection()) {
duke@435:     return VM_GC_Operation::doit_prologue();
duke@435:   } else {
duke@435:     return false;
duke@435:   }
duke@435: }
duke@435: 
duke@435: bool VM_GC_HeapInspection::skip_operation() const {
duke@435:   assert(Universe::heap()->supports_heap_inspection(), "huh?");
duke@435:   return false;
duke@435: }
duke@435: 
duke@435: void VM_GC_HeapInspection::doit() {
duke@435:   HandleMark hm;
duke@435:   CollectedHeap* ch = Universe::heap();
duke@435:   if (_full_gc) {
duke@435:     ch->collect_as_vm_thread(GCCause::_heap_inspection);
duke@435:   } else {
duke@435:     // make the heap parsable (no need to retire TLABs)
duke@435:     ch->ensure_parsability(false);
duke@435:   }
ysr@1050:   HeapInspection::heap_inspection(_out, _need_prologue /* need_prologue */);
duke@435: }
duke@435: 
duke@435: 
duke@435: void VM_GenCollectForAllocation::doit() {
duke@435:   JvmtiGCForAllocationMarker jgcm;
duke@435:   notify_gc_begin(false);
duke@435: 
duke@435:   GenCollectedHeap* gch = GenCollectedHeap::heap();
duke@435:   GCCauseSetter gccs(gch, _gc_cause);
duke@435:   _res = gch->satisfy_failed_allocation(_size, _tlab);
duke@435:   assert(gch->is_in_reserved_or_null(_res), "result not in heap");
duke@435: 
duke@435:   if (_res == NULL && GC_locker::is_active_and_needs_gc()) {
duke@435:     set_gc_locked();
duke@435:   }
duke@435:   notify_gc_end();
duke@435: }
duke@435: 
duke@435: void VM_GenCollectFull::doit() {
duke@435:   JvmtiGCFullMarker jgcm;
duke@435:   notify_gc_begin(true);
duke@435: 
duke@435:   GenCollectedHeap* gch = GenCollectedHeap::heap();
duke@435:   GCCauseSetter gccs(gch, _gc_cause);
duke@435:   gch->do_full_collection(gch->must_clear_all_soft_refs(), _max_level);
duke@435:   notify_gc_end();
duke@435: }
apetrusenko@574: 
apetrusenko@574: void VM_GenCollectForPermanentAllocation::doit() {
apetrusenko@574:   JvmtiGCForAllocationMarker jgcm;
apetrusenko@574:   notify_gc_begin(true);
ysr@777:   SharedHeap* heap = (SharedHeap*)Universe::heap();
ysr@777:   GCCauseSetter gccs(heap, _gc_cause);
ysr@777:   switch (heap->kind()) {
ysr@777:     case (CollectedHeap::GenCollectedHeap): {
ysr@777:       GenCollectedHeap* gch = (GenCollectedHeap*)heap;
ysr@777:       gch->do_full_collection(gch->must_clear_all_soft_refs(),
ysr@777:                               gch->n_gens() - 1);
ysr@777:       break;
ysr@777:     }
ysr@777: #ifndef SERIALGC
ysr@777:     case (CollectedHeap::G1CollectedHeap): {
ysr@777:       G1CollectedHeap* g1h = (G1CollectedHeap*)heap;
ysr@777:       g1h->do_full_collection(_gc_cause == GCCause::_last_ditch_collection);
ysr@777:       break;
ysr@777:     }
ysr@777: #endif // SERIALGC
ysr@777:     default:
ysr@777:       ShouldNotReachHere();
ysr@777:   }
ysr@777:   _res = heap->perm_gen()->allocate(_size, false);
ysr@777:   assert(heap->is_in_reserved_or_null(_res), "result not in heap");
apetrusenko@574:   if (_res == NULL && GC_locker::is_active_and_needs_gc()) {
apetrusenko@574:     set_gc_locked();
apetrusenko@574:   }
apetrusenko@574:   notify_gc_end();
apetrusenko@574: }