Hi all,
I'm trying to debug a deadlock I get when trying to open the print dialog in Internet Explorer, the backtrace I get looks like this:
=>0 0x420cdb44 (NTDLL.DLL.memcpy+0x516f4) (ebp=435f0c54) 1 0x400b8d2f (NTDLL.DLL.NtWaitForMultipleObjects+0x133 in libntdll.dll.so) (ebp=435f0cf0) 2 0x400b7557 (usr1_handler+0x3b(__signal=0xa, __context=0x4f) [signal_i386.c:1132] in libntdll.dll.so) (ebp=435f0d1c) 3 0x42028c48 (NTDLL.DLL.toupper+0x6748) (ebp=437126e8) 4 0x400b8d2f (NTDLL.DLL.NtWaitForMultipleObjects+0x133 in libntdll.dll.so) (ebp=43712784) 5 0x400b8d59 (NtWaitForSingleObject+0x25(handle=0x260, alertable=0x0, timeout=0x437127c0) [sync.c:594] in libntdll.dll.so) (ebp=437127a4) 6 0x400a6e53 (RtlpWaitForCriticalSection+0xdb(crit=0x70460350) [critsection.c:162] in libntdll.dll.so) (ebp=43712828) 7 0x400a7020 (RtlEnterCriticalSection+0x34(crit=0x70460350) [critsection.c:1920] in libntdll.dll.so) (ebp=4371283c) 8 0x70457e56 (MLANG.DLL.ConvertINetString+0x4f85 in C:\WINDOWS\SYSTEM\MLANG.DLL) (ebp=4371286c) 9 0x70eaf851 (MSHTML.DLL.com_ms_osp_ospmrshl_releaseByValExternal+0x82912 in C:\WINDOWS\SYSTEM\MSHTML.DLL) (ebp=43712990) 10 0x70e60c0f (MSHTML.DLL.com_ms_osp_ospmrshl_releaseByValExternal+0x33cd0 in C:\WINDOWS\SYSTEM\MSHTML.DLL) (ebp=43712a2c) 11 0x70d94e1c (MSHTML.DLL.EntryPoint+0xbd49 in C:\WINDOWS\SYSTEM\MSHTML.DLL) (ebp=43712a4c) 12 0x70cbe59f (MSHTML.DLL..text+0x6d59f in C:\WINDOWS\SYSTEM\MSHTML.DLL) (ebp=43712a6c) 13 0x70d570e3 (MSHTML.DLL.DllGetClassObject+0x17b2f in C:\WINDOWS\SYSTEM\MSHTML.DLL) (ebp=43712ce4) 14 0x70d3bff7 (MSHTML.DLL.DllCanUnloadNow+0x28c44 in C:\WINDOWS\SYSTEM\MSHTML.DLL) (ebp=43712d50) 15 0x70e2621d (MSHTML.DLL.CreateHTMLPropertyPage+0x41f87 in C:\WINDOWS\SYSTEM\MSHTML.DLL) (ebp=43712d8c) 16 0xffffffff (OLE32.DLL..reloc+0x80018fff) (ebp=00000000)
The null ebp at the top is kind of odd, I think this stack might be the result of a demarshalled RPC call. But anyway. As you can see it's blocking on a critical section, but I don't know how to find out which thread has got suck inside it. I tried putting trace statements in Rtl(Enter/Leave)CriticalSection, oops, not a good idea, waaaay too much spew there to be useful.
So, what I'd like to know is whether there is any way to find out which thread has entered that critical section. Also, is this even a good idea, or is there a better way to debug thread deadlocks?
thanks -mike