X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fruntime%2Fx86-arch.h;h=582bfc7e016b668ee47b33285b5eecea099e36b9;hb=ed1910efb36f71b5ebe33b5ffffd7195e15644de;hp=82daa1939974b6591964f739a8c741cb6859b2f4;hpb=402958f92506b9d3de852601b8c1ccb99b5ee558;p=sbcl.git

diff --git a/src/runtime/x86-arch.h b/src/runtime/x86-arch.h
index 82daa19..582bfc7 100644
--- a/src/runtime/x86-arch.h
+++ b/src/runtime/x86-arch.h
@@ -9,6 +9,8 @@
 #error genesis/config.h (or sbcl.h) must be included before this file
 #endif
 
+#include "interr.h"                     /* for declaration of lose() */
+
 #define ARCH_HAS_STACK_POINTER
 
 /* FIXME: Do we also want
@@ -16,10 +18,22 @@
  * here? (The answer wasn't obvious to me when merging the
  * architecture-abstracting patches for CSR's SPARC port. -- WHN 2002-02-15) */
 
-#include "interr.h"
+#define COMPILER_BARRIER \
+    do { __asm__ __volatile__ ( "" : : : "memory"); } while (0)
+
+#ifdef LISP_FEATURE_WIN32
+extern int os_number_of_processors;
+#define yield_on_uniprocessor()                 \
+    do { if (os_number_of_processors<=1) SwitchToThread(); } while(0)
+#else
+/* Stubs are better than ifdef EVERYWHERE. */
+#define yield_on_uniprocessor()                 \
+    do {} while(0)
+#endif
+
 
 static inline void
-get_spinlock(volatile lispobj *word,long value)
+get_spinlock(volatile lispobj *word, unsigned long value)
 {
 #ifdef LISP_FEATURE_SB_THREAD
     u32 eax=0;
@@ -27,19 +41,22 @@ get_spinlock(volatile lispobj *word,long value)
         lose("recursive get_spinlock: 0x%x,%ld\n",word,value);
     do {
 #if defined(LISP_FEATURE_DARWIN)
-        asm ("xor %0,%0;\n\
+        asm volatile ("xor %0,%0;\n\
               lock/cmpxchg %1,%2"
              : "=a" (eax)
              : "r" (value), "m" (*word)
              : "memory", "cc");
 #else
-        asm ("xor %0,%0\n\
+        if (eax!=0) {
+            asm volatile("rep; nop");
+        }
+        asm volatile ("xor %0,%0\n\
               lock cmpxchg %1,%2"
              : "=a" (eax)
              : "r" (value), "m" (*word)
              : "memory", "cc");
 #endif
-
+        yield_on_uniprocessor();
     } while(eax!=0);
 #else
     *word=value;
@@ -49,22 +66,23 @@ get_spinlock(volatile lispobj *word,long value)
 static inline void
 release_spinlock(volatile lispobj *word)
 {
+    /* See comment in RELEASE-SPINLOCK in target-thread.lisp. */
+    COMPILER_BARRIER;
     *word=0;
+    COMPILER_BARRIER;
 }
 
-#include <stdio.h>
-
 static inline lispobj
 swap_lispobjs(volatile lispobj *dest, lispobj value)
 {
     lispobj old_value;
 #if defined(LISP_FEATURE_DARWIN)
-    asm ("lock/xchg %0,(%1)"
+    asm volatile ("lock/xchg %0,(%1)"
          : "=r" (old_value)
          : "r" (dest), "0" (value)
          : "memory");
 #else
-    asm ("lock xchg %0,(%1)"
+    asm volatile ("lock xchg %0,(%1)"
          : "=r" (old_value)
          : "r" (dest), "0" (value)
          : "memory");