FAULTING_IP: WTF!WTF::WorkQueue::performWorkOnRegisteredWorkThread+70 [c:\cygwin\home\buildbot\slave\win-release\build\source\wtf\wtf\win\workqueuewin.cpp @ 60] 71d0b1a0 8b0e mov ecx,dword ptr [esi] EXCEPTION_RECORD: ffffffffffffffff -- (.exr 0xffffffffffffffff) .exr 0xffffffffffffffff ExceptionAddress: 0000000071d0b1a0 (WTF!std::unique_ptr<WTF::Function<void __cdecl(void)>::CallableWrapperBase,std::default_delete<WTF::Function<void __cdecl(void)>::CallableWrapperBase> >::get) ExceptionCode: c0000005 (Access violation) ExceptionFlags: 00000000 NumberParameters: 2 Parameter[0]: 0000000000000000 Parameter[1]: 0000000000000000 Attempt to read from address 0000000000000000 CONTEXT: 0000000000000000 -- (.cxr 0x0;r) .cxr 0x0;r eax=090dd7d8 ebx=24375f60 ecx=08ef1484 edx=00289208 esi=00000000 edi=08ef147c eip=71d0b1a0 esp=0928f798 ebp=0928f7b4 iopl=0 nv up ei pl nz na po nc cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010202 WTF!std::unique_ptr<WTF::Function<void __cdecl(void)>::CallableWrapperBase,std::default_delete<WTF::Function<void __cdecl(void)>::CallableWrapperBase> >::get [inlined in WTF!WTF::WorkQueue::performWorkOnRegisteredWorkThread+0x70]: 71d0b1a0 8b0e mov ecx,dword ptr [esi] ds:002b:00000000=???????? .cxr STACK_TEXT: 0928f7b4 71d0b0f0 08ef1578 0928f834 77da7edf WTF!WTF::WorkQueue::performWorkOnRegisteredWorkThread+0x70 0928f7c0 77da7edf 08ef1478 353b3e3a 08ef1578 WTF!WTF::WorkQueue::workThreadCallback+0x20 WARNING: Stack unwind information not available. Following frames may be wrong. 0928f834 77d90951 08ef1478 08ef1578 353b3f8a ntdll_77d40000!RtlClearAllBits+0x110 0928f984 7699336a 00705980 0928f9d0 77d79902 ntdll_77d40000!TpCallbackIndependent+0x710 0928f990 77d79902 00705980 353b3fde 00000000 KERNEL32!BaseThreadInitThunk+0x12 0928f9d0 77d798d5 77d9046c 00705980 00000000 ntdll_77d40000!RtlInitializeExceptionChain+0x63 0928f9e8 00000000 77d9046c 00705980 00000000 ntdll_77d40000!RtlInitializeExceptionChain+0x36
Created attachment 319280 [details] Patch
Comment on attachment 319280 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=319280&action=review > Source/WTF/wtf/win/WorkQueueWin.cpp:62 > + function(); I think we should understand how a nullptr function is getting into this Vector. Maybe we could just protect against nullptr functions being placed in the queue? We don't seem to do this kind of null-check elsewhere in the code, so it seems like an anti-pattern.
Created attachment 319283 [details] Patch
(In reply to Brent Fulgham from comment #2) > Comment on attachment 319280 [details] > Patch > > View in context: > https://bugs.webkit.org/attachment.cgi?id=319280&action=review > > > Source/WTF/wtf/win/WorkQueueWin.cpp:62 > > + function(); > > I think we should understand how a nullptr function is getting into this > Vector. Maybe we could just protect against nullptr functions being placed > in the queue? We don't seem to do this kind of null-check elsewhere in the > code, so it seems like an anti-pattern. Thanks! That's a good point, I have updated the patch.
Comment on attachment 319283 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=319283&action=review > Source/WTF/wtf/win/WorkQueueWin.cpp:105 > + ASSERT(function); > + if (!function) > + return; Maybe this should be accompanied with a FIXME and a bug to fix the underlying issue?
Created attachment 319291 [details] Patch
(In reply to Saam Barati from comment #5) > Comment on attachment 319283 [details] > Patch > > View in context: > https://bugs.webkit.org/attachment.cgi?id=319283&action=review > > > Source/WTF/wtf/win/WorkQueueWin.cpp:105 > > + ASSERT(function); > > + if (!function) > > + return; > > Maybe this should be accompanied with a FIXME and a bug to fix the > underlying issue? Yes, thank you! I have updated the patch.
Comment on attachment 319291 [details] Patch Clearing flags on attachment: 319291 Committed r221323: <http://trac.webkit.org/changeset/221323>
All reviewed patches have been landed. Closing bug.
<rdar://problem/34146574>