void G1MMUTrackerQueue::add_pause(double start, double end, bool gc_thread) {
double longest_allowed = longest_pause_internal(start);
if (longest_allowed < 0.0)
longest_allowed = 0.0;
double duration = end - start;
remove_expired_entries(end);
if (_no_entries == QueueLength) {
// OK, right now when we fill up we bomb out
// there are a few ways of dealing with this "gracefully"
// increase the array size (:-)
// remove the oldest entry (this might allow more GC time for
// the time slice than what's allowed)
// consolidate the two entries with the minimum gap between them
// (this might allow less GC time than what's allowed)
guarantee(NOT_PRODUCT(ScavengeALot ||) G1UseFixedWindowMMUTracker,
"array full, currently we can't recover unless +G1UseFixedWindowMMUTracker");
// In the case where ScavengeALot is true, such overflow is not
// uncommon; in such cases, we can, without much loss of precision
// or performance (we are GC'ing most of the time anyway!),
// simply overwrite the oldest entry in the tracker: this
// is also the behaviour when G1UseFixedWindowMMUTracker is enabled.
_head_index = trim_index(_head_index + 1);
assert(_head_index == _tail_index, "Because we have a full circular buffer");
_tail_index = trim_index(_tail_index + 1);
} else {
void G1MMUTrackerQueue::add_pause(double start, double end, bool gc_thread) {
double longest_allowed = longest_pause_internal(start);
if (longest_allowed < 0.0)
longest_allowed = 0.0;
double duration = end - start;
remove_expired_entries(end);
if (_no_entries == QueueLength) {
// OK, we've filled up the queue. There are a few ways
// of dealing with this "gracefully"
// increase the array size (:-)
// remove the oldest entry (this might allow more GC time for
// the time slice than what's allowed) - this is what we
// currently do
// consolidate the two entries with the minimum gap between them
// (this might allow less GC time than what's allowed)
// In the case where ScavengeALot is true, such overflow is not
// uncommon; in such cases, we can, without much loss of precision
// or performance (we are GC'ing most of the time anyway!),
// simply overwrite the oldest entry in the tracker.
_head_index = trim_index(_head_index + 1);
assert(_head_index == _tail_index, "Because we have a full circular buffer");
_tail_index = trim_index(_tail_index + 1);
} else {
_head_index = trim_index(_head_index + 1);
++_no_entries;
}
_array[_head_index] = G1MMUTrackerQueueElem(start, end);
}
double G1MMUTrackerQueue::when_sec(double current_time, double pause_time) {
if (_DISABLE_MMU)
return 0.0;
MutexLockerEx x(MMUTracker_lock, Mutex::_no_safepoint_check_flag);
remove_expired_entries(current_time);
return when_internal(current_time, pause_time);
}
double G1MMUTrackerQueue::longest_pause(double current_time) {
if (_DISABLE_MMU)
return _max_gc_time;
MutexLockerEx x(MMUTracker_lock, Mutex::_no_safepoint_check_flag);
remove_expired_entries(current_time);
return longest_pause_internal(current_time);
}
