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/*
* Copyright 2001-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
*/
# include "incls/_precompiled.incl"
# include "incls/_collectedHeap.cpp.incl"
#ifdef ASSERT
int CollectedHeap::_fire_out_of_memory_count = 0;
#endif
// Memory state functions.
CollectedHeap::CollectedHeap() :
_reserved(), _barrier_set(NULL), _is_gc_active(false),
_total_collections(0), _total_full_collections(0),
_gc_cause(GCCause::_no_gc), _gc_lastcause(GCCause::_no_gc) {
NOT_PRODUCT(_promotion_failure_alot_count = 0;)
NOT_PRODUCT(_promotion_failure_alot_gc_number = 0;)
if (UsePerfData) {
EXCEPTION_MARK;
// create the gc cause jvmstat counters
_perf_gc_cause = PerfDataManager::create_string_variable(SUN_GC, "cause",
80, GCCause::to_string(_gc_cause), CHECK);
_perf_gc_lastcause =
PerfDataManager::create_string_variable(SUN_GC, "lastCause",
80, GCCause::to_string(_gc_lastcause), CHECK);
}
}
#ifndef PRODUCT
void CollectedHeap::check_for_bad_heap_word_value(HeapWord* addr, size_t size) {
if (CheckMemoryInitialization && ZapUnusedHeapArea) {
for (size_t slot = 0; slot < size; slot += 1) {
assert((*(intptr_t*) (addr + slot)) != ((intptr_t) badHeapWordVal),
"Found badHeapWordValue in post-allocation check");
}
}
}
void CollectedHeap::check_for_non_bad_heap_word_value(HeapWord* addr, size_t size)
{
if (CheckMemoryInitialization && ZapUnusedHeapArea) {
for (size_t slot = 0; slot < size; slot += 1) {
assert((*(intptr_t*) (addr + slot)) == ((intptr_t) badHeapWordVal),
"Found non badHeapWordValue in pre-allocation check");
}
}
}
#endif // PRODUCT
#ifdef ASSERT
void CollectedHeap::check_for_valid_allocation_state() {
Thread *thread = Thread::current();
// How to choose between a pending exception and a potential
// OutOfMemoryError? Don't allow pending exceptions.
// This is a VM policy failure, so how do we exhaustively test it?
assert(!thread->has_pending_exception(),
"shouldn't be allocating with pending exception");
if (StrictSafepointChecks) {
assert(thread->allow_allocation(),
"Allocation done by thread for which allocation is blocked "
"by No_Allocation_Verifier!");
// Allocation of an oop can always invoke a safepoint,
// hence, the true argument
thread->check_for_valid_safepoint_state(true);
}
}
#endif
HeapWord* CollectedHeap::allocate_from_tlab_slow(Thread* thread, size_t size) {
// Retain tlab and allocate object in shared space if
// the amount free in the tlab is too large to discard.
if (thread->tlab().free() > thread->tlab().refill_waste_limit()) {
thread->tlab().record_slow_allocation(size);
return NULL;
}
// Discard tlab and allocate a new one.
// To minimize fragmentation, the last TLAB may be smaller than the rest.
size_t new_tlab_size = thread->tlab().compute_size(size);
thread->tlab().clear_before_allocation();
if (new_tlab_size == 0) {
return NULL;
}
// Allocate a new TLAB...
HeapWord* obj = Universe::heap()->allocate_new_tlab(new_tlab_size);
if (obj == NULL) {
return NULL;
}
if (ZeroTLAB) {
// ..and clear it.
Copy::zero_to_words(obj, new_tlab_size);
} else {
// ...and clear just the allocated object.
Copy::zero_to_words(obj, size);
}
thread->tlab().fill(obj, obj + size, new_tlab_size);
return obj;
}
oop CollectedHeap::new_store_barrier(oop new_obj) {
// %%% This needs refactoring. (It was imported from the server compiler.)
guarantee(can_elide_tlab_store_barriers(), "store barrier elision not supported");
BarrierSet* bs = this->barrier_set();
assert(bs->has_write_region_opt(), "Barrier set does not have write_region");
int new_size = new_obj->size();
bs->write_region(MemRegion((HeapWord*)new_obj, new_size));
return new_obj;
}
bool CollectedHeap::can_elide_permanent_oop_store_barriers() const {
// %%% This needs refactoring. (It was gating logic from the server compiler.)
guarantee(kind() < CollectedHeap::G1CollectedHeap, "");
return !UseConcMarkSweepGC;
}
HeapWord* CollectedHeap::allocate_new_tlab(size_t size) {
guarantee(false, "thread-local allocation buffers not supported");
return NULL;
}
void CollectedHeap::fill_all_tlabs(bool retire) {
assert(UseTLAB, "should not reach here");
// See note in ensure_parsability() below.
assert(SafepointSynchronize::is_at_safepoint() ||
!is_init_completed(),
"should only fill tlabs at safepoint");
// The main thread starts allocating via a TLAB even before it
// has added itself to the threads list at vm boot-up.
assert(Threads::first() != NULL,
"Attempt to fill tlabs before main thread has been added"
" to threads list is doomed to failure!");
for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
thread->tlab().make_parsable(retire);
}
}
void CollectedHeap::ensure_parsability(bool retire_tlabs) {
// The second disjunct in the assertion below makes a concession
// for the start-up verification done while the VM is being
// created. Callers be careful that you know that mutators
// aren't going to interfere -- for instance, this is permissible
// if we are still single-threaded and have either not yet
// started allocating (nothing much to verify) or we have
// started allocating but are now a full-fledged JavaThread
// (and have thus made our TLAB's) available for filling.
assert(SafepointSynchronize::is_at_safepoint() ||
!is_init_completed(),
"Should only be called at a safepoint or at start-up"
" otherwise concurrent mutator activity may make heap "
" unparsable again");
if (UseTLAB) {
fill_all_tlabs(retire_tlabs);
}
}
void CollectedHeap::accumulate_statistics_all_tlabs() {
if (UseTLAB) {
assert(SafepointSynchronize::is_at_safepoint() ||
!is_init_completed(),
"should only accumulate statistics on tlabs at safepoint");
ThreadLocalAllocBuffer::accumulate_statistics_before_gc();
}
}
void CollectedHeap::resize_all_tlabs() {
if (UseTLAB) {
assert(SafepointSynchronize::is_at_safepoint() ||
!is_init_completed(),
"should only resize tlabs at safepoint");
ThreadLocalAllocBuffer::resize_all_tlabs();
}
}
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