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[PATCH 2/2] pthread_once: Use futex wrappers with error checking.
- From: Torvald Riegel <triegel at redhat dot com>
- To: GLIBC Devel <libc-alpha at sourceware dot org>
- Date: Thu, 04 Dec 2014 21:57:15 +0100
- Subject: [PATCH 2/2] pthread_once: Use futex wrappers with error checking.
- Authentication-results: sourceware.org; auth=none
- References: <1417726487 dot 22797 dot 48 dot camel at triegel dot csb>
This uses the new glibc-internal futex wrappers from Patch 1/2 in
pthread_once.
Tested on x86 and x86_64.
2014-12-05 Torvald Riegel <triegel@redhat.com>
* nptl/pthread_once.c (clear_once_control): Use futex wrappers with
error checking.
(__pthread_once_slow): Likewise.
commit d9cf9ffe8b1df575a3d9c9a8fd08e5b7463a1c38
Author: Torvald Riegel <triegel@redhat.com>
Date: Thu Dec 4 14:29:27 2014 +0100
pthread_once: Use futex wrappers with error checking.
diff --git a/nptl/pthread_once.c b/nptl/pthread_once.c
index 9bb82e9..61ccd13 100644
--- a/nptl/pthread_once.c
+++ b/nptl/pthread_once.c
@@ -17,7 +17,7 @@
<http://www.gnu.org/licenses/>. */
#include "pthreadP.h"
-#include <lowlevellock.h>
+#include <futex-internal.h>
#include <atomic.h>
@@ -35,7 +35,7 @@ clear_once_control (void *arg)
get interrupted (see __pthread_once), so all we need to relay to other
threads is the state being reset again. */
atomic_store_relaxed (once_control, 0);
- lll_futex_wake (once_control, INT_MAX, LLL_PRIVATE);
+ futex_wake (once_control, INT_MAX, FUTEX_PRIVATE);
}
@@ -100,8 +100,11 @@ __pthread_once_slow (pthread_once_t *once_control, void (*init_routine) (void))
is set and __PTHREAD_ONCE_DONE is not. */
if (val == newval)
{
- /* Same generation, some other thread was faster. Wait. */
- lll_futex_wait (once_control, newval, LLL_PRIVATE);
+ /* Same generation, some other thread was faster. Wait and
+ retry. Ignore the return value because all possible
+ values (0, -EWOULDBLOCK, -EINTR) need to be handled the
+ same. */
+ futex_wait (once_control, newval, FUTEX_PRIVATE);
continue;
}
}
@@ -122,7 +125,7 @@ __pthread_once_slow (pthread_once_t *once_control, void (*init_routine) (void))
atomic_store_release (once_control, __PTHREAD_ONCE_DONE);
/* Wake up all other threads. */
- lll_futex_wake (once_control, INT_MAX, LLL_PRIVATE);
+ futex_wake (once_control, INT_MAX, FUTEX_PRIVATE);
break;
}