Don't compile the pthread based memory-barrier fall back unless we

actually need it.



git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@5158 d4fa192b-c00b-0410-8231-f00ffab90ce4

include/vmb.h

@@ -74,6 +74,8 @@ void vmb_pthread(void);
 
 #else
 
+#define VMB_NEEDS_PTHREAD_WORKAROUND_THIS_IS_BAD_FOR_PERFORMANCE 1
+
 #define VMB()	vmb_pthread()
 #define VWMB()	vmb_pthread()
 #define VRMB()	vmb_pthread()

lib/libvarnish/vmb.c

@@ -30,6 +30,8 @@
 #include "libvarnish.h"
 #include "vmb.h"
 
+#ifdef VMB_NEEDS_PTHREAD_WORKAROUND_THIS_IS_BAD_FOR_PERFORMANCE
+
 static pthread_mutex_t	mb_mtx;
 static pthread_once_t	mb_mtx_once = PTHREAD_ONCE_INIT;
 
@@ -50,3 +52,5 @@ vmb_pthread(void)
 	AZ(pthread_mutex_lock(&mb_mtx));
 	AZ(pthread_mutex_unlock(&mb_mtx));
 }
+
+#endif