2004.12.20 19:27 "[Tiff] multithreading issues", by Bill Bither

2004.12.20 20:42 "Re: [Tiff] multithreading issues", by Frank Warmerdam

For testing we are using XP Pro. It's being used in the .NET framework, I'm unsure if it's a problem with other development environments. We made no other changes to our code other than upgrading LibTiff, and we made all necessary multithreading precautions in our code. Version 3.6.1 doesn't express this behavior, while 3.7.X CVS does.


Are you using tif_win32.c? I had some strange heap corruption (or so it seemed) problems in heavy use of 3.7.x CVS a few weeks ago which went away when I switched to using tif_unix.c (on win32) as opposed to tif_win32.c. In my case I was running a hefty test stream which included alot of TIFF usage and was seeing roughly random crashes which seemed to be indicative of heap corruption.

I don't know if the core problem was ever resolved, but I was unable to reproduce it on unix, or under purify. I suspected it was a problem with my code free()ing something allocated with a TIFF function or the other way around (as tif_win32 does not use malloc() directly) but my efforts at verifying this failed.

Purify always seems to fail me when I need it most, and it is my only memory checker on win32. On linux I use valgrind which I found found to be emmensely helpful into isolating subtle problems that are not win32 specific.

Best regards,

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