freebsd-ports/devel/linuxthreads/files/patch-barrier
Tor Egge c717b11e0d Backport 2002-03-22 fix from newer linuxthreads versions defining
MEMORY_BARRIER() as a asm op which clobbers memory to avoid unintended
reordering by the compiler.
2006-05-28 17:32:39 +00:00

21 lines
865 B
Text

--- internals.h.orig Tue May 16 00:23:50 2006
+++ internals.h Tue May 16 00:24:21 2006
@@ -395,12 +395,14 @@
#endif
}
-/* If MEMORY_BARRIER isn't defined in pt-machine.h, assume the architecture
- doesn't need a memory barrier instruction (e.g. Intel x86). Some
- architectures distinguish between full, read and write barriers. */
+/* If MEMORY_BARRIER isn't defined in pt-machine.h, assume the
+ architecture doesn't need a memory barrier instruction (e.g. Intel
+ x86). Still we need the compiler to respect the barrier and emit
+ all outstanding operations which modify memory. Some architectures
+ distinguish between full, read and write barriers. */
#ifndef MEMORY_BARRIER
-#define MEMORY_BARRIER()
+#define MEMORY_BARRIER() asm ("" : : : "memory")
#endif
#ifndef READ_MEMORY_BARRIER
#define READ_MEMORY_BARRIER() MEMORY_BARRIER()