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authorAustin Foxley <austinf@cetoncorp.com>2009-10-17 12:26:24 -0700
committerAustin Foxley <austinf@cetoncorp.com>2009-10-17 12:26:24 -0700
commitc68d0fa2d88fc2134a38d99e7e944828384a7671 (patch)
tree6596943bd1c77f18d6e49d4153ddd3f3d67b49f5 /libpthread/nptl/pthread_mutex_timedlock.c
parent9a03e98a3b418f33c347a6023e9320f3a42cb9e4 (diff)
libpthread/nptl: core of the "Native Posix Threading Library" for uClibc
targetting arm,sh,i386,mips,sparc for now Signed-off-by: Austin Foxley <austinf@cetoncorp.com>
Diffstat (limited to 'libpthread/nptl/pthread_mutex_timedlock.c')
-rw-r--r--libpthread/nptl/pthread_mutex_timedlock.c118
1 files changed, 118 insertions, 0 deletions
diff --git a/libpthread/nptl/pthread_mutex_timedlock.c b/libpthread/nptl/pthread_mutex_timedlock.c
new file mode 100644
index 000000000..1cd2c7e60
--- /dev/null
+++ b/libpthread/nptl/pthread_mutex_timedlock.c
@@ -0,0 +1,118 @@
+/* Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
+
+ 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <errno.h>
+#include "pthreadP.h"
+#include <lowlevellock.h>
+
+
+int
+pthread_mutex_timedlock (mutex, abstime)
+ pthread_mutex_t *mutex;
+ const struct timespec *abstime;
+{
+ pid_t id = THREAD_GETMEM (THREAD_SELF, tid);
+ int result = 0;
+
+ /* We must not check ABSTIME here. If the thread does not block
+ abstime must not be checked for a valid value. */
+
+ switch (mutex->__data.__kind)
+ {
+ /* Recursive mutex. */
+ case PTHREAD_MUTEX_RECURSIVE_NP:
+ /* Check whether we already hold the mutex. */
+ if (mutex->__data.__owner == id)
+ {
+ /* Just bump the counter. */
+ if (__builtin_expect (mutex->__data.__count + 1 == 0, 0))
+ /* Overflow of the counter. */
+ return EAGAIN;
+
+ ++mutex->__data.__count;
+
+ goto out;
+ }
+ else
+ {
+ /* We have to get the mutex. */
+ result = lll_mutex_timedlock (mutex->__data.__lock, abstime);
+
+ if (result != 0)
+ goto out;
+
+ /* Only locked once so far. */
+ mutex->__data.__count = 1;
+ }
+ break;
+
+ /* Error checking mutex. */
+ case PTHREAD_MUTEX_ERRORCHECK_NP:
+ /* Check whether we already hold the mutex. */
+ if (mutex->__data.__owner == id)
+ return EDEADLK;
+
+ /* FALLTHROUGH */
+
+ default:
+ /* Correct code cannot set any other type. */
+ case PTHREAD_MUTEX_TIMED_NP:
+ simple:
+ /* Normal mutex. */
+ result = lll_mutex_timedlock (mutex->__data.__lock, abstime);
+ break;
+
+ case PTHREAD_MUTEX_ADAPTIVE_NP:
+ if (! __is_smp)
+ goto simple;
+
+ if (lll_mutex_trylock (mutex->__data.__lock) != 0)
+ {
+ int cnt = 0;
+ int max_cnt = MIN (MAX_ADAPTIVE_COUNT,
+ mutex->__data.__spins * 2 + 10);
+ do
+ {
+ if (cnt++ >= max_cnt)
+ {
+ result = lll_mutex_timedlock (mutex->__data.__lock, abstime);
+ break;
+ }
+
+#ifdef BUSY_WAIT_NOP
+ BUSY_WAIT_NOP;
+#endif
+ }
+ while (lll_mutex_trylock (mutex->__data.__lock) != 0);
+
+ mutex->__data.__spins += (cnt - mutex->__data.__spins) / 8;
+ }
+ break;
+ }
+
+ if (result == 0)
+ {
+ /* Record the ownership. */
+ mutex->__data.__owner = id;
+ ++mutex->__data.__nusers;
+ }
+
+ out:
+ return result;
+}