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authorRoland McGrath <roland@hack.frob.com>2014-07-07 09:28:38 -0700
committerRoland McGrath <roland@hack.frob.com>2014-07-07 09:28:38 -0700
commit08192659bbeae149e7cb1f4c43547257f7099bb0 (patch)
tree9f602a4e9f0aefdb06bc15a76be46e958e91a58f /nptl/sem_timedwait.c
parent96baf6ffc57b811bbc424a1fc72ef77dd56d7a18 (diff)
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Get rid of nptl/sysdeps/ entirely!
Diffstat (limited to 'nptl/sem_timedwait.c')
-rw-r--r--nptl/sem_timedwait.c116
1 files changed, 116 insertions, 0 deletions
diff --git a/nptl/sem_timedwait.c b/nptl/sem_timedwait.c
new file mode 100644
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+++ b/nptl/sem_timedwait.c
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+/* sem_timedwait -- wait on a semaphore.  Generic futex-using version.
+   Copyright (C) 2003-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <sysdep.h>
+#include <lowlevellock.h>
+#include <internaltypes.h>
+#include <semaphore.h>
+
+#include <pthreadP.h>
+#include <shlib-compat.h>
+
+
+extern void __sem_wait_cleanup (void *arg) attribute_hidden;
+
+/* This is in a seperate function in order to make sure gcc
+   puts the call site into an exception region, and thus the
+   cleanups get properly run.  */
+static int
+__attribute__ ((noinline))
+do_futex_timed_wait (struct new_sem *isem, struct timespec *rt)
+{
+  int err, oldtype = __pthread_enable_asynccancel ();
+
+  err = lll_futex_timed_wait (&isem->value, 0, rt,
+			      isem->private ^ FUTEX_PRIVATE_FLAG);
+
+  __pthread_disable_asynccancel (oldtype);
+  return err;
+}
+
+int
+sem_timedwait (sem_t *sem, const struct timespec *abstime)
+{
+  struct new_sem *isem = (struct new_sem *) sem;
+  int err;
+
+  if (atomic_decrement_if_positive (&isem->value) > 0)
+    return 0;
+
+  if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
+    {
+      __set_errno (EINVAL);
+      return -1;
+    }
+
+  atomic_increment (&isem->nwaiters);
+
+  pthread_cleanup_push (__sem_wait_cleanup, isem);
+
+  while (1)
+    {
+      struct timeval tv;
+      struct timespec rt;
+      int sec, nsec;
+
+      /* Get the current time.  */
+      __gettimeofday (&tv, NULL);
+
+      /* Compute relative timeout.  */
+      sec = abstime->tv_sec - tv.tv_sec;
+      nsec = abstime->tv_nsec - tv.tv_usec * 1000;
+      if (nsec < 0)
+	{
+	  nsec += 1000000000;
+	  --sec;
+	}
+
+      /* Already timed out?  */
+      if (sec < 0)
+	{
+	  __set_errno (ETIMEDOUT);
+	  err = -1;
+	  break;
+	}
+
+      /* Do wait.  */
+      rt.tv_sec = sec;
+      rt.tv_nsec = nsec;
+      err = do_futex_timed_wait(isem, &rt);
+      if (err != 0 && err != -EWOULDBLOCK)
+	{
+	  __set_errno (-err);
+	  err = -1;
+	  break;
+	}
+
+      if (atomic_decrement_if_positive (&isem->value) > 0)
+	{
+	  err = 0;
+	  break;
+	}
+    }
+
+  pthread_cleanup_pop (0);
+
+  atomic_decrement (&isem->nwaiters);
+
+  return err;
+}