aboutsummaryrefslogtreecommitdiff
path: root/nptl/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h
diff options
context:
space:
mode:
Diffstat (limited to 'nptl/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h')
-rw-r--r--nptl/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h17
1 files changed, 16 insertions, 1 deletions
diff --git a/nptl/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h b/nptl/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h
index a715879dbd..e9f895d6e8 100644
--- a/nptl/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h
+++ b/nptl/sysdeps/unix/sysv/linux/powerpc/lowlevellock.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2003 Free Software Foundation, Inc.
+/* Copyright (C) 2003, 2004 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003.
@@ -100,6 +100,21 @@
#define lll_mutex_trylock(lock) __lll_trylock (&(lock))
+/* Set *futex to 2 if it is 0, atomically. Returns the old value */
+#define lll_mutex_cond_trylock(futex) \
+ ({ int __val; \
+ __asm __volatile ("1: lwarx %0,0,%2\n" \
+ " cmpwi 0,%0,0\n" \
+ " bne 2f\n" \
+ " stwcx. %3,0,%2\n" \
+ " bne- 1b\n" \
+ "2: " __lll_acq_instr \
+ : "=&r" (__val), "=m" (*futex) \
+ : "r" (futex), "r" (2), "1" (*futex) \
+ : "cr0", "memory"); \
+ __val; \
+ })
+
extern void __lll_lock_wait (int *futex) attribute_hidden;