RTS tidyup sweep, first phase

[ghc-hetmet.git] / includes / rts / storage / SMPClosureOps.h

diff --git a/includes/rts/storage/SMPClosureOps.h b/includes/rts/storage/SMPClosureOps.h
new file mode 100644 (file)
index 0000000..d5f7c3f
--- /dev/null
+++ b/includes/rts/storage/SMPClosureOps.h
@@ -0,0 +1,78 @@
+/* ----------------------------------------------------------------------------
+ *
+ * (c) The GHC Team, 2005
+ *
+ * Macros for THREADED_RTS support
+ *
+ * -------------------------------------------------------------------------- */
+
+#ifndef RTS_STORAGE_SMPCLOSUREOPS_H
+#define RTS_STORAGE_SMPCLOSUREOPS_H
+
+#ifdef CMINUSMINUS
+
+#define unlockClosure(ptr,info)                 \
+    prim %write_barrier() [];                   \
+    StgHeader_info(ptr) = info;    
+
+#else
+
+EXTERN_INLINE StgInfoTable *lockClosure(StgClosure *p);
+EXTERN_INLINE void unlockClosure(StgClosure *p, const StgInfoTable *info);
+
+#if defined(THREADED_RTS)
+
+/* -----------------------------------------------------------------------------
+ * Locking/unlocking closures
+ *
+ * This is used primarily in the implementation of MVars.
+ * -------------------------------------------------------------------------- */
+
+#define SPIN_COUNT 4000
+
+// We want a callable copy of lockClosure() so that we can refer to it
+// from .cmm files compiled using the native codegen.
+EXTERN_INLINE StgInfoTable *lockClosure(StgClosure *p)
+{
+    StgWord info;
+    do {
+       nat i = 0;
+       do {
+           info = xchg((P_)(void *)&p->header.info, (W_)&stg_WHITEHOLE_info);
+           if (info != (W_)&stg_WHITEHOLE_info) return (StgInfoTable *)info;
+       } while (++i < SPIN_COUNT);
+       yieldThread();
+    } while (1);
+}
+
+EXTERN_INLINE void unlockClosure(StgClosure *p, const StgInfoTable *info)
+{
+    // This is a strictly ordered write, so we need a write_barrier():
+    write_barrier();
+    p->header.info = info;
+}
+
+#else /* !THREADED_RTS */
+
+EXTERN_INLINE StgInfoTable *
+lockClosure(StgClosure *p)
+{ return (StgInfoTable *)p->header.info; }
+
+EXTERN_INLINE void
+unlockClosure(StgClosure *p STG_UNUSED, const StgInfoTable *info STG_UNUSED)
+{ /* nothing */ }
+
+#endif /* THREADED_RTS */
+
+// Handy specialised versions of lockClosure()/unlockClosure()
+EXTERN_INLINE void lockTSO(StgTSO *tso);
+EXTERN_INLINE void lockTSO(StgTSO *tso)
+{ lockClosure((StgClosure *)tso); }
+
+EXTERN_INLINE void unlockTSO(StgTSO *tso);
+EXTERN_INLINE void unlockTSO(StgTSO *tso)
+{ unlockClosure((StgClosure*)tso, (const StgInfoTable *)&stg_TSO_info); }
+
+#endif /* CMINUSMINUS */
+
+#endif /* RTS_STORAGE_SMPCLOSUREOPS_H */