This is the mail archive of the cygwin mailing list for the Cygwin project.
Index Nav: | [Date Index] [Subject Index] [Author Index] [Thread Index] | |
---|---|---|
Message Nav: | [Date Prev] [Date Next] | [Thread Prev] [Thread Next] |
Other format: | [Raw text] |
The libapr1 test cases are failing again for flock locks. This same test case failed with 1.7.9 with a fatal error[1], but that was corrected. The test is no longer encountering the fatal error, but it is producing the wrong result. I extracted the attached STC to demonstrate the problem. It starts a number of child processes, each of which repeatedly grab and release a lock on a temporary file. While they have the lock, the increment a counter in shared memory in a racy way. If all goes well, the counter should end up having the value of CHILDREN * ITERS_PER_CHILDREN. And it does, sometimes. Other times, however, it's less than this value, indicating the lock did not work. (I'm using shmget for shared memory, so you have to have cygserver running. APR has a number of shared memory methods, including mmap, but this was the easiest for me to extract.) As before, I haven't been doing C programming in a while, so I'm not 100% sure the test case is valid, but it does demonstrate the same problem the APR test case is having. I've tried this on my Win7-64 box running the 20120210 snapshot and on a WinXP running stock 1.7.10. I get the same results in both places. Regards, David [1] http://cygwin.com/ml/cygwin/2011-08/msg00480.html -- David Rothenberger ---- daveroth@acm.org I think we are in Rats' Alley where the dead men lost their bones. -- T.S. Eliot
Attachment:
stc-flock-fork.c
Description: Text document
-- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Index Nav: | [Date Index] [Subject Index] [Author Index] [Thread Index] | |
---|---|---|
Message Nav: | [Date Prev] [Date Next] | [Thread Prev] [Thread Next] |