// This method contains all heap specific policy for invoking scavenge.
// PSScavenge::invoke_no_policy() will do nothing but attempt to
// scavenge. It will not clean up after failed promotions, bail out if
// we've exceeded policy time limits, or any other special behavior.
// All such policy should be placed here.
//
// Note that this method should only be called from the vm_thread while
// at a safepoint!
bool PSScavenge::invoke() {
assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
assert(!Universe::heap()->is_gc_active(), "not reentrant");
ParallelScavengeHeap* const heap = (ParallelScavengeHeap*)Universe::heap();
assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
PSAdaptiveSizePolicy* policy = heap->size_policy();
IsGCActiveMark mark;
const bool scavenge_done = PSScavenge::invoke_no_policy();
const bool need_full_gc = !scavenge_done ||
policy->should_full_GC(heap->old_gen()->free_in_bytes());
bool full_gc_done = false;
if (UsePerfData) {
PSGCAdaptivePolicyCounters* const counters = heap->gc_policy_counters();
const int ffs_val = need_full_gc ? full_follows_scavenge : not_skipped;
counters->update_full_follows_scavenge(ffs_val);
}
if (need_full_gc) {
GCCauseSetter gccs(heap, GCCause::_adaptive_size_policy);
CollectorPolicy* cp = heap->collector_policy();
const bool clear_all_softrefs = cp->should_clear_all_soft_refs();
if (UseParallelOldGC) {
full_gc_done = PSParallelCompact::invoke_no_policy(clear_all_softrefs);
} else {
full_gc_done = PSMarkSweep::invoke_no_policy(clear_all_softrefs);
}
}
return full_gc_done;
}
void VM_CollectForMetadataAllocation::doit() {
SvcGCMarker sgcm(SvcGCMarker::FULL);
CollectedHeap* heap = Universe::heap();
GCCauseSetter gccs(heap, _gc_cause);
// Check again if the space is available. Another thread
// may have similarly failed a metadata allocation and induced
// a GC that freed space for the allocation.
if (!MetadataAllocationFailALot) {
_result = _loader_data->metaspace_non_null()->allocate(_size, _mdtype);
}
if (_result == NULL) {
if (UseConcMarkSweepGC) {
if (CMSClassUnloadingEnabled) {
MetaspaceGC::set_should_concurrent_collect(true);
}
// For CMS expand since the collection is going to be concurrent.
_result =
_loader_data->metaspace_non_null()->expand_and_allocate(_size, _mdtype);
}
if (_result == NULL) {
// Don't clear the soft refs yet.
if (Verbose && PrintGCDetails && UseConcMarkSweepGC) {
gclog_or_tty->print_cr("\nCMS full GC for Metaspace");
}
heap->collect_as_vm_thread(GCCause::_metadata_GC_threshold);
// After a GC try to allocate without expanding. Could fail
// and expansion will be tried below.
_result =
_loader_data->metaspace_non_null()->allocate(_size, _mdtype);
}
if (_result == NULL) {
// If still failing, allow the Metaspace to expand.
// See delta_capacity_until_GC() for explanation of the
// amount of the expansion.
// This should work unless there really is no more space
// or a MaxMetaspaceSize has been specified on the command line.
_result =
_loader_data->metaspace_non_null()->expand_and_allocate(_size, _mdtype);
if (_result == NULL) {
// If expansion failed, do a last-ditch collection and try allocating
// again. A last-ditch collection will clear softrefs. This
// behavior is similar to the last-ditch collection done for perm
// gen when it was full and a collection for failed allocation
// did not free perm gen space.
heap->collect_as_vm_thread(GCCause::_last_ditch_collection);
_result =
_loader_data->metaspace_non_null()->allocate(_size, _mdtype);
}
}
if (Verbose && PrintGCDetails && _result == NULL) {
gclog_or_tty->print_cr("\nAfter Metaspace GC failed to allocate size "
SIZE_FORMAT, _size);
}
}
if (_result == NULL && GC_locker::is_active_and_needs_gc()) {
set_gc_locked();
}
}
