* [PATCH] pthread/tst-cancel28: Fix barrier re-init race condition
@ 2021-09-25 8:02 Stafford Horne via Libc-alpha
2021-09-27 20:42 ` Stafford Horne via Libc-alpha
2021-09-28 13:47 ` Adhemerval Zanella via Libc-alpha
0 siblings, 2 replies; 3+ messages in thread
From: Stafford Horne via Libc-alpha @ 2021-09-25 8:02 UTC (permalink / raw
To: GLIBC patches
When running this test on the OpenRISC port I am working on this test
fails with a timeout. The test passes when being straced or debugged.
Looking at the code there seems to be a race condition in that:
1 main thread: calls xpthread_cancel
2 sub thread : receives cancel signal
3 sub thread : cleanup routine waits on barrier
4 main thread: re-inits barrier
5 main thread: waits on barrier
After getting to 5 the main thread and sub thread wait forever as the 2
barriers are no longer the same.
Removing the barrier re-init seems to fix this issue. Also, the barrier
does not need to be reinitialized as that is done by default.
Cc: Adhemerval Zanella <adhemerval.zanella@linaro.org>
---
sysdeps/pthread/tst-cancel28.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/sysdeps/pthread/tst-cancel28.c b/sysdeps/pthread/tst-cancel28.c
index 627cbc8160..9286c159b3 100644
--- a/sysdeps/pthread/tst-cancel28.c
+++ b/sysdeps/pthread/tst-cancel28.c
@@ -69,7 +69,6 @@ do_test (void)
xpthread_cancel (timer_thread);
- xpthread_barrier_init (&barrier, NULL, 2);
xpthread_barrier_wait (&barrier);
return 0;
--
2.31.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] pthread/tst-cancel28: Fix barrier re-init race condition
2021-09-25 8:02 [PATCH] pthread/tst-cancel28: Fix barrier re-init race condition Stafford Horne via Libc-alpha
@ 2021-09-27 20:42 ` Stafford Horne via Libc-alpha
2021-09-28 13:47 ` Adhemerval Zanella via Libc-alpha
1 sibling, 0 replies; 3+ messages in thread
From: Stafford Horne via Libc-alpha @ 2021-09-27 20:42 UTC (permalink / raw
To: GLIBC patches
ping
On Sat, Sep 25, 2021 at 5:02 PM Stafford Horne <shorne@gmail.com> wrote:
>
> When running this test on the OpenRISC port I am working on this test
> fails with a timeout. The test passes when being straced or debugged.
> Looking at the code there seems to be a race condition in that:
>
> 1 main thread: calls xpthread_cancel
> 2 sub thread : receives cancel signal
> 3 sub thread : cleanup routine waits on barrier
> 4 main thread: re-inits barrier
> 5 main thread: waits on barrier
>
> After getting to 5 the main thread and sub thread wait forever as the 2
> barriers are no longer the same.
>
> Removing the barrier re-init seems to fix this issue. Also, the barrier
> does not need to be reinitialized as that is done by default.
>
> Cc: Adhemerval Zanella <adhemerval.zanella@linaro.org>
> ---
> sysdeps/pthread/tst-cancel28.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/sysdeps/pthread/tst-cancel28.c b/sysdeps/pthread/tst-cancel28.c
> index 627cbc8160..9286c159b3 100644
> --- a/sysdeps/pthread/tst-cancel28.c
> +++ b/sysdeps/pthread/tst-cancel28.c
> @@ -69,7 +69,6 @@ do_test (void)
>
> xpthread_cancel (timer_thread);
>
> - xpthread_barrier_init (&barrier, NULL, 2);
> xpthread_barrier_wait (&barrier);
>
> return 0;
> --
> 2.31.1
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] pthread/tst-cancel28: Fix barrier re-init race condition
2021-09-25 8:02 [PATCH] pthread/tst-cancel28: Fix barrier re-init race condition Stafford Horne via Libc-alpha
2021-09-27 20:42 ` Stafford Horne via Libc-alpha
@ 2021-09-28 13:47 ` Adhemerval Zanella via Libc-alpha
1 sibling, 0 replies; 3+ messages in thread
From: Adhemerval Zanella via Libc-alpha @ 2021-09-28 13:47 UTC (permalink / raw
To: Stafford Horne, GLIBC patches
On 25/09/2021 05:02, Stafford Horne wrote:
> When running this test on the OpenRISC port I am working on this test
> fails with a timeout. The test passes when being straced or debugged.
> Looking at the code there seems to be a race condition in that:
>
> 1 main thread: calls xpthread_cancel
> 2 sub thread : receives cancel signal
> 3 sub thread : cleanup routine waits on barrier
> 4 main thread: re-inits barrier
> 5 main thread: waits on barrier
>
> After getting to 5 the main thread and sub thread wait forever as the 2
> barriers are no longer the same.
>
> Removing the barrier re-init seems to fix this issue. Also, the barrier
> does not need to be reinitialized as that is done by default.
>
> Cc: Adhemerval Zanella <adhemerval.zanella@linaro.org>
LGTM, thanks.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
> ---
> sysdeps/pthread/tst-cancel28.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/sysdeps/pthread/tst-cancel28.c b/sysdeps/pthread/tst-cancel28.c
> index 627cbc8160..9286c159b3 100644
> --- a/sysdeps/pthread/tst-cancel28.c
> +++ b/sysdeps/pthread/tst-cancel28.c
> @@ -69,7 +69,6 @@ do_test (void)
>
> xpthread_cancel (timer_thread);
>
> - xpthread_barrier_init (&barrier, NULL, 2);
> xpthread_barrier_wait (&barrier);
>
> return 0;
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-09-25 8:02 [PATCH] pthread/tst-cancel28: Fix barrier re-init race condition Stafford Horne via Libc-alpha
2021-09-27 20:42 ` Stafford Horne via Libc-alpha
2021-09-28 13:47 ` Adhemerval Zanella via Libc-alpha
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