8025852: Remove unnecessary setters in collector policy classes
Summary: Use instance variables directly within the collector policy classes and remove unused setters.
Reviewed-by: tschatzl, jcoomes
/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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* 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).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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#include "precompiled.hpp"
#include "gc_implementation/g1/concurrentMarkThread.inline.hpp"
#include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
#include "gc_implementation/g1/g1CollectorPolicy.hpp"
#include "gc_implementation/g1/g1Log.hpp"
#include "gc_implementation/g1/vm_operations_g1.hpp"
#include "gc_implementation/shared/gcTimer.hpp"
#include "gc_implementation/shared/gcTraceTime.hpp"
#include "gc_implementation/shared/isGCActiveMark.hpp"
#include "gc_implementation/g1/vm_operations_g1.hpp"
#include "runtime/interfaceSupport.hpp"
VM_G1CollectForAllocation::VM_G1CollectForAllocation(
unsigned int gc_count_before,
size_t word_size)
: VM_G1OperationWithAllocRequest(gc_count_before, word_size,
GCCause::_allocation_failure) {
guarantee(word_size > 0, "an allocation should always be requested");
}
void VM_G1CollectForAllocation::doit() {
G1CollectedHeap* g1h = G1CollectedHeap::heap();
GCCauseSetter x(g1h, _gc_cause);
_result = g1h->satisfy_failed_allocation(_word_size, &_pause_succeeded);
assert(_result == NULL || _pause_succeeded,
"if we get back a result, the pause should have succeeded");
}
void VM_G1CollectFull::doit() {
G1CollectedHeap* g1h = G1CollectedHeap::heap();
GCCauseSetter x(g1h, _gc_cause);
g1h->do_full_collection(false /* clear_all_soft_refs */);
}
VM_G1IncCollectionPause::VM_G1IncCollectionPause(
unsigned int gc_count_before,
size_t word_size,
bool should_initiate_conc_mark,
double target_pause_time_ms,
GCCause::Cause gc_cause)
: VM_G1OperationWithAllocRequest(gc_count_before, word_size, gc_cause),
_should_initiate_conc_mark(should_initiate_conc_mark),
_target_pause_time_ms(target_pause_time_ms),
_should_retry_gc(false),
_old_marking_cycles_completed_before(0) {
guarantee(target_pause_time_ms > 0.0,
err_msg("target_pause_time_ms = %1.6lf should be positive",
target_pause_time_ms));
_gc_cause = gc_cause;
}
bool VM_G1IncCollectionPause::doit_prologue() {
bool res = VM_GC_Operation::doit_prologue();
if (!res) {
if (_should_initiate_conc_mark) {
// The prologue can fail for a couple of reasons. The first is that another GC
// got scheduled and prevented the scheduling of the initial mark GC. The
// second is that the GC locker may be active and the heap can't be expanded.
// In both cases we want to retry the GC so that the initial mark pause is
// actually scheduled. In the second case, however, we should stall until
// until the GC locker is no longer active and then retry the initial mark GC.
_should_retry_gc = true;
}
}
return res;
}
void VM_G1IncCollectionPause::doit() {
G1CollectedHeap* g1h = G1CollectedHeap::heap();
assert(!_should_initiate_conc_mark ||
((_gc_cause == GCCause::_gc_locker && GCLockerInvokesConcurrent) ||
(_gc_cause == GCCause::_java_lang_system_gc && ExplicitGCInvokesConcurrent) ||
_gc_cause == GCCause::_g1_humongous_allocation),
"only a GC locker, a System.gc() or a hum allocation induced GC should start a cycle");
if (_word_size > 0) {
// An allocation has been requested. So, try to do that first.
_result = g1h->attempt_allocation_at_safepoint(_word_size,
false /* expect_null_cur_alloc_region */);
if (_result != NULL) {
// If we can successfully allocate before we actually do the
// pause then we will consider this pause successful.
_pause_succeeded = true;
return;
}
}
GCCauseSetter x(g1h, _gc_cause);
if (_should_initiate_conc_mark) {
// It's safer to read old_marking_cycles_completed() here, given
// that noone else will be updating it concurrently. Since we'll
// only need it if we're initiating a marking cycle, no point in
// setting it earlier.
_old_marking_cycles_completed_before = g1h->old_marking_cycles_completed();
// At this point we are supposed to start a concurrent cycle. We
// will do so if one is not already in progress.
bool res = g1h->g1_policy()->force_initial_mark_if_outside_cycle(_gc_cause);
// The above routine returns true if we were able to force the
// next GC pause to be an initial mark; it returns false if a
// marking cycle is already in progress.
//
// If a marking cycle is already in progress just return and skip the
// pause below - if the reason for requesting this initial mark pause
// was due to a System.gc() then the requesting thread should block in
// doit_epilogue() until the marking cycle is complete.
//
// If this initial mark pause was requested as part of a humongous
// allocation then we know that the marking cycle must just have
// been started by another thread (possibly also allocating a humongous
// object) as there was no active marking cycle when the requesting
// thread checked before calling collect() in
// attempt_allocation_humongous(). Retrying the GC, in this case,
// will cause the requesting thread to spin inside collect() until the
// just started marking cycle is complete - which may be a while. So
// we do NOT retry the GC.
if (!res) {
assert(_word_size == 0, "Concurrent Full GC/Humongous Object IM shouldn't be allocating");
if (_gc_cause != GCCause::_g1_humongous_allocation) {
_should_retry_gc = true;
}
return;
}
}
_pause_succeeded =
g1h->do_collection_pause_at_safepoint(_target_pause_time_ms);
if (_pause_succeeded && _word_size > 0) {
// An allocation had been requested.
_result = g1h->attempt_allocation_at_safepoint(_word_size,
true /* expect_null_cur_alloc_region */);
} else {
assert(_result == NULL, "invariant");
if (!_pause_succeeded) {
// Another possible reason reason for the pause to not be successful
// is that, again, the GC locker is active (and has become active
// since the prologue was executed). In this case we should retry
// the pause after waiting for the GC locker to become inactive.
_should_retry_gc = true;
}
}
}
void VM_G1IncCollectionPause::doit_epilogue() {
VM_GC_Operation::doit_epilogue();
// If the pause was initiated by a System.gc() and
// +ExplicitGCInvokesConcurrent, we have to wait here for the cycle
// that just started (or maybe one that was already in progress) to
// finish.
if (_gc_cause == GCCause::_java_lang_system_gc &&
_should_initiate_conc_mark) {
assert(ExplicitGCInvokesConcurrent,
"the only way to be here is if ExplicitGCInvokesConcurrent is set");
G1CollectedHeap* g1h = G1CollectedHeap::heap();
// In the doit() method we saved g1h->old_marking_cycles_completed()
// in the _old_marking_cycles_completed_before field. We have to
// wait until we observe that g1h->old_marking_cycles_completed()
// has increased by at least one. This can happen if a) we started
// a cycle and it completes, b) a cycle already in progress
// completes, or c) a Full GC happens.
// If the condition has already been reached, there's no point in
// actually taking the lock and doing the wait.
if (g1h->old_marking_cycles_completed() <=
_old_marking_cycles_completed_before) {
// The following is largely copied from CMS
Thread* thr = Thread::current();
assert(thr->is_Java_thread(), "invariant");
JavaThread* jt = (JavaThread*)thr;
ThreadToNativeFromVM native(jt);
MutexLockerEx x(FullGCCount_lock, Mutex::_no_safepoint_check_flag);
while (g1h->old_marking_cycles_completed() <=
_old_marking_cycles_completed_before) {
FullGCCount_lock->wait(Mutex::_no_safepoint_check_flag);
}
}
}
}
void VM_CGC_Operation::acquire_pending_list_lock() {
assert(_needs_pll, "don't call this otherwise");
// The caller may block while communicating
// with the SLT thread in order to acquire/release the PLL.
ConcurrentMarkThread::slt()->
manipulatePLL(SurrogateLockerThread::acquirePLL);
}
void VM_CGC_Operation::release_and_notify_pending_list_lock() {
assert(_needs_pll, "don't call this otherwise");
// The caller may block while communicating
// with the SLT thread in order to acquire/release the PLL.
ConcurrentMarkThread::slt()->
manipulatePLL(SurrogateLockerThread::releaseAndNotifyPLL);
}
void VM_CGC_Operation::doit() {
gclog_or_tty->date_stamp(G1Log::fine() && PrintGCDateStamps);
TraceCPUTime tcpu(G1Log::finer(), true, gclog_or_tty);
GCTraceTime t(_printGCMessage, G1Log::fine(), true, G1CollectedHeap::heap()->gc_timer_cm());
SharedHeap* sh = SharedHeap::heap();
// This could go away if CollectedHeap gave access to _gc_is_active...
if (sh != NULL) {
IsGCActiveMark x;
_cl->do_void();
} else {
_cl->do_void();
}
}
bool VM_CGC_Operation::doit_prologue() {
// Note the relative order of the locks must match that in
// VM_GC_Operation::doit_prologue() or deadlocks can occur
if (_needs_pll) {
acquire_pending_list_lock();
}
Heap_lock->lock();
SharedHeap::heap()->_thread_holds_heap_lock_for_gc = true;
return true;
}
void VM_CGC_Operation::doit_epilogue() {
// Note the relative order of the unlocks must match that in
// VM_GC_Operation::doit_epilogue()
SharedHeap::heap()->_thread_holds_heap_lock_for_gc = false;
Heap_lock->unlock();
if (_needs_pll) {
release_and_notify_pending_list_lock();
}
}