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Diffstat (limited to 'nptl/sysdeps/pthread/pthread_cond_signal.c')
-rw-r--r--nptl/sysdeps/pthread/pthread_cond_signal.c63
1 files changed, 63 insertions, 0 deletions
diff --git a/nptl/sysdeps/pthread/pthread_cond_signal.c b/nptl/sysdeps/pthread/pthread_cond_signal.c
new file mode 100644
index 0000000000..1a035fe05f
--- /dev/null
+++ b/nptl/sysdeps/pthread/pthread_cond_signal.c
@@ -0,0 +1,63 @@
+/* Copyright (C) 2003 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Martin Schwidefsky <schwidefsky@de.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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <endian.h>
+#include <errno.h>
+#include <sysdep.h>
+#include <lowlevellock.h>
+#include <pthread.h>
+#include <pthreadP.h>
+
+#include <shlib-compat.h>
+
+int
+__pthread_cond_signal (cond)
+ pthread_cond_t *cond;
+{
+ /* Make sure we are alone. */
+ lll_mutex_lock(cond->__data.__lock);
+
+ /* Are there any waiters to be woken? */
+ if (cond->__data.__total_seq > cond->__data.__wakeup_seq)
+ {
+ /* Yes. Mark one of them as woken. */
+ ++cond->__data.__wakeup_seq;
+
+ /* The futex syscall operates on a 32-bit word. That is fine,
+ we just use the low 32 bits of the sequence counter. */
+#if BYTE_ORDER == LITTLE_ENDIAN
+ int *futex = ((int *) (&cond->__data.__wakeup_seq));
+#elif BYTE_ORDER == BIG_ENDIAN
+ int *futex = ((int *) (&cond->__data.__wakeup_seq)) + 1;
+#else
+# error "No valid byte order"
+#endif
+
+ /* Wake one. */
+ lll_futex_wake (futex, 1);
+ }
+
+ /* We are done. */
+ lll_mutex_unlock (cond->__data.__lock);
+
+ return 0;
+}
+
+versioned_symbol (libpthread, __pthread_cond_signal, pthread_cond_signal,
+ GLIBC_2_3_2);