I've seen a few null derefs in MemoryPressureHandler::uninstall() after sending synthetic memory pressure signals to WebKit. Looks like a race.
Created attachment 180757 [details] Patch
Comment on attachment 180757 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=180757&action=review > Source/WebCore/platform/mac/MemoryPressureHandlerMac.mm:89 > + dispatch_source_cancel(_cache_event_source); It might be a good idea to check if _cache_event_source is not null.
Committed r138482: <http://trac.webkit.org/changeset/138482>
<rdar://problem/12889515>