817725 - Short (seconds) hangs of UI [@ _WriteFileImplementation]

Status: RESOLVED WONTFIX

(Thunderbird :: General, defect)

Description

[Honza Bambas (:mayhemer)]

Recently (during the last week?) I started to experience hangs of TB 19 UI just while reading emails.

I attached VC++ and downloaded the proper symbols+sources and when the hang happens, VC shows this stack:

 	ntdll.dll!_NtWriteFile@36()  + 0x15 bytes	
 	ntdll.dll!_NtWriteFile@36()  + 0x15 bytes	
>	kernel32.dll!_WriteFileImplementation@20()  + 0x4a bytes	

The rest of the stack trace is bogus, twice it showed a different crap, so I don't know where from this method is being called.  ProcessExplorer says nothing.

Comment 1

[Wayne Mery (:wsmwk)]

Not much to go on :(

Nothing coincidental happening in Error Console or Activity Manager?

Comment 2

[Honza Bambas (:mayhemer)]

Hmm.. it might be a bug in logging which I have turned on for POP3 service (break before call to _WriteFileImplementation shows):

 	kernel32.dll!_WriteFileImplementation@20()  + 0x45 bytes	
 	msvcr100.dll!_write_nolock(int fh=4, const void * buf=0x003bd3bc, unsigned int cnt=1)  Line 332 + 0x2c bytes	C
 	msvcr100.dll!_write(int fh=4, const void * buf=0x003bd3bc, unsigned int cnt=1)  Line 74 + 0xc bytes	C
 	msvcr100.dll!_flsbuf(int ch=10, _iobuf * str=0x00000004)  Line 189 + 0xd bytes	C
 	msvcr100.dll!_fwrite_nolock(const void * buffer=0x00f15000, unsigned int size=1, unsigned int num=91, _iobuf * stream=0x720e2088)  Line 194 + 0x7 bytes	C
 	msvcr100.dll!fwrite(const void * buffer=0x00f15000, unsigned int size=1, unsigned int count=91, _iobuf * stream=0x720e2088)  Line 83 + 0x11 bytes	C
 	nspr4.dll!PR_LogFlush()  Line 530 + 0x30 bytes	C
 	nspr4.dll!PR_LogPrint(const char * fmt=0x5c941610, ...)  Line 522 + 0x5 bytes	C
>	xul.dll!nsPop3Protocol::LoadUrl(nsIURI * aURL=0x0db5c888, nsISupports * __formal=0x00000000)  Line 1072 + 0x16 bytes	C++

PR_LogFlush could be the cause, since I have "append" in the list of modules and the file can easily become 7GB (Giga!) long.

I think this is invalid then.

I'll turn of logging and recheck.

Comment 3

[Honza Bambas (:mayhemer)]

Since I've turned off logging, I cannot reproduce.  Closing as WONTFIX.

Comment 4

[:aceman]

Does it flush the file to disk after each line? That could be a slowdown. But that may be needed for logging as the app could crash (instability may be the reason for enabling the log) and unflushed lines could be lost.

Comment 5

[Honza Bambas (:mayhemer)]

(In reply to :aceman from comment #4)
> Does it flush the file to disk after each line? That could be a slowdown.
> But that may be needed for logging as the app could crash (instability may
> be the reason for enabling the log) and unflushed lines could be lost.

sync module was not defined.  I think it is flushing after some number of lines, since the NSPR log buffer is relatively small.