Changes between Version 11 and Version 12 of FrequentlyAskedQuestions


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Timestamp:
01/11/11 14:05:54 (10 years ago)
Author:
salcock
Comment:

Updated FAQ for threading bug

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  • FrequentlyAskedQuestions

    v11 v12  
    1515
    1616=== When using libtrace 3.0.7 or 3.0.8, I get a segmentation fault whenever I try to read a trace file! ===
    17 There appears to be a nasty threading bug that can crop up when libtrace is built with gcc 4.4.1 (which is the packaged version on many Ubuntu systems).
     17There appears to be a nasty threading bug that can crop up when libtrace is built with optimisations on a 32-bit system.
    1818
    19  * The best possible fix (until libtrace 3.0.9 is released) is to make the change described in r1681 and re-build libtrace. Obviously this will involve editing the libtrace source code but will fix the problem without impacting on performance.
     19 * One possible fix (until libtrace 3.0.9 is released) is to make the change described in r1681 and re-build libtrace. Obviously this will involve editing the libtrace source code but will fix the problem without impacting on performance.
    2020 * An alternative is to disable threaded IO by running 'export LIBTRACEIO=nothreads' in the terminal which you are using to run the failing libtrace program. This will disable threaded IO, which will make the trace processing slower.
    2121 * You could also disable optimisations by adding 'CFLAGS="-g -O0"' when running ./configure - this will mean that you can still use threaded IO but the entirety of libtrace will be unoptimised.
    2222
     23UPDATE: the root cause has now been identified and fixed in r1685. Anyone seriously affected by this bug can email us at contact@wand.net.nz and we can provide a pre-release version of libtrace 3.0.9 that includes the fix.