Should fix issue #7. We now do a write barrier before setting the 'ca…

…ched' field to 1 so that reader don't see this get re-ordered before all the fields are readable.
fusesource · Sep 9, 2013 · d9cd0ab · d9cd0ab
1 parent ae07fd2
commit d9cd0ab
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diff --git a/hawtjni-generator/src/main/java/org/fusesource/hawtjni/generator/StructsGenerator.java b/hawtjni-generator/src/main/java/org/fusesource/hawtjni/generator/StructsGenerator.java
@@ -240,6 +240,8 @@ void generateCacheFunction(JNIClass clazz) {
                 output("\"");
             outputln(");");
         }
+        // Makes sure compiler/cpu does not reorder the following write before the previous updates are done.
+        outputln("\thawtjni_w_barrier();");
         output("\t");
         output(simpleName);
         outputln("Fc.cached = 1;");

diff --git a/hawtjni-generator/src/main/resources/hawtjni.h b/hawtjni-generator/src/main/resources/hawtjni.h
@@ -168,6 +168,25 @@ void throwOutOfMemory(JNIEnv *env);
   #endif 
 #endif /* JNI64 */
 
+#ifdef __GNUC__
+  #define hawtjni_w_barrier() __sync_synchronize()
+#elif defined(SOLARIS2) && SOLARIS2 >= 10
+  #include <mbarrier.h>
+  #define hawtjni_w_barrier() __machine_w_barrier()
+#elif defined(__APPLE__)
+  #include <libkern/OSAtomic.h>
+  #define hawtjni_w_barrier() OSMemoryBarrier()
+#elif defined(_WIN32) || defined(_WIN64)
+  #include <intrin.h>
+  #define hawtjni_w_barrier() _mm_sfence(); _WriteBarrier()
+#else
+  #pragma message ( "Don't know how to do a memory barrier on this platform" )
+  #define hawtjni_w_barrier()
+#endif
+
+void hawtjni_atomic_set(jlong *target, jlong value);
+jlong hawtjni_atomic_get(jlong *target);
+
 #ifdef __cplusplus
 }
 #endif