void VM_GC_HeapInspection::doit() {
HandleMark hm;
CollectedHeap* ch = Universe::heap();
ch->ensure_parsability(false); // must happen, even if collection does
// not happen (e.g. due to GC_locker)
if (_full_gc) {
// The collection attempt below would be skipped anyway if
// the gc locker is held. The following dump may then be a tad
// misleading to someone expecting only live objects to show
// up in the dump (see CR 6944195). Just issue a suitable warning
// in that case and do not attempt to do a collection.
// The latter is a subtle point, because even a failed attempt
// to GC will, in fact, induce one in the future, which we
// probably want to avoid in this case because the GC that we may
// be about to attempt holds value for us only
// if it happens now and not if it happens in the eventual
// future.
if (GC_locker::is_active()) {
warning("GC locker is held; pre-dump GC was skipped");
} else {
ch->collect_as_vm_thread(GCCause::_heap_inspection);
}
}
HeapInspection::heap_inspection(_out, _need_prologue /* need_prologue */);
}
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();
}
}
