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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/lowlevellock.c
parent96baf6ffc57b811bbc424a1fc72ef77dd56d7a18 (diff)
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Get rid of nptl/sysdeps/ entirely!
Diffstat (limited to 'nptl/lowlevellock.c')
-rw-r--r--nptl/lowlevellock.c124
1 files changed, 124 insertions, 0 deletions
diff --git a/nptl/lowlevellock.c b/nptl/lowlevellock.c
new file mode 100644
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+++ b/nptl/lowlevellock.c
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+/* low level locking for pthread library. 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 <sys/time.h>
+#include <atomic.h>
+
+void
+__lll_lock_wait_private (int *futex)
+{
+ if (*futex == 2)
+ lll_futex_wait (futex, 2, LLL_PRIVATE);
+
+ while (atomic_exchange_acq (futex, 2) != 0)
+ lll_futex_wait (futex, 2, LLL_PRIVATE);
+}
+
+
+/* These functions don't get included in libc.so */
+#ifdef IS_IN_libpthread
+void
+__lll_lock_wait (int *futex, int private)
+{
+ if (*futex == 2)
+ lll_futex_wait (futex, 2, private);
+
+ while (atomic_exchange_acq (futex, 2) != 0)
+ lll_futex_wait (futex, 2, private);
+}
+
+
+int
+__lll_timedlock_wait (int *futex, const struct timespec *abstime, int private)
+{
+ /* Reject invalid timeouts. */
+ if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
+ return EINVAL;
+
+ /* Try locking. */
+ while (atomic_exchange_acq (futex, 2) != 0)
+ {
+ struct timeval tv;
+
+ /* Get the current time. */
+ (void) __gettimeofday (&tv, NULL);
+
+ /* Compute relative timeout. */
+ struct timespec rt;
+ rt.tv_sec = abstime->tv_sec - tv.tv_sec;
+ rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000;
+ if (rt.tv_nsec < 0)
+ {
+ rt.tv_nsec += 1000000000;
+ --rt.tv_sec;
+ }
+
+ if (rt.tv_sec < 0)
+ return ETIMEDOUT;
+
+ /* Wait. */
+ lll_futex_timed_wait (futex, 2, &rt, private);
+ }
+
+ return 0;
+}
+
+
+int
+__lll_timedwait_tid (int *tidp, const struct timespec *abstime)
+{
+ int tid;
+
+ if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)
+ return EINVAL;
+
+ /* Repeat until thread terminated. */
+ while ((tid = *tidp) != 0)
+ {
+ struct timeval tv;
+ struct timespec rt;
+
+ /* Get the current time. */
+ (void) __gettimeofday (&tv, NULL);
+
+ /* Compute relative timeout. */
+ rt.tv_sec = abstime->tv_sec - tv.tv_sec;
+ rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000;
+ if (rt.tv_nsec < 0)
+ {
+ rt.tv_nsec += 1000000000;
+ --rt.tv_sec;
+ }
+
+ /* Already timed out? */
+ if (rt.tv_sec < 0)
+ return ETIMEDOUT;
+
+ /* Wait until thread terminates. The kernel so far does not use
+ the private futex operations for this. */
+ if (lll_futex_timed_wait (tidp, tid, &rt, LLL_SHARED) == -ETIMEDOUT)
+ return ETIMEDOUT;
+ }
+
+ return 0;
+}
+#endif