Re: [Bug 2829] New: posix_locks_deadlock() loops infinitely

[Ichiko Sakamoto <i-sakamoto@pb.jp.nec.com>]

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Andrew Morton wrote:

> Andrew Morton <akpm@osdl.org> wrote:
> 
>>
>>
>>Begin forwarded message:
>>
>>Date: Thu, 3 Jun 2004 22:45:56 -0700
>>From: bugme-daemon@osdl.org
>>To: bugme-new@lists.osdl.org
>>Subject: Spam: [Bugme-new] [Bug 2829] New: posix_locks_deadlock() loops infinitely
>>
> 
> 
> Do you have a test app which demonstrates the bug?



Please compile attached source files.
$ gcc -o proc_A proc_A.c -lpthread
$ gcc -o proc_B proc_B.c -lpthread
$ gcc -o proc_C proc_C.c -lpthread

Then create 3 files.
$ touch ./file1
$ touch ./file2
$ touch ./file3

Run 3 procs.
$ ./proc_A & ./proc_B & ./proc_C &

Create file named "1", then "A1" thread will lock "file1".
$ touch 1

Create file named "2", then "B1" will lock "file2".
$ touch 2

Create file named "3", then "C1" will lock "file3".
$ touch 3

Create file named "4", then "A2" will try to lock "file2".
$ touch 4

Create file named "5", then "A3" will try to lock "file3".
$ touch 5

Create file named "6", then "B2" will try to lock "file1".
$ touch 6
Here, deadlock detection fails.

Create file named "7", then "C1" will unlock "file3".
$ touch 7

Create file named "8", then "A3" will unlock "file3".
$ touch 8

Create file named "9", then "C2" trys to lock "file1".
$ touch 9
Here, posix_locks_deadlock() hangs.




-- 
Ichiko Sakamoto

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