[project @ 2004-08-13 13:04:50 by simonmar]

[ghc-hetmet.git] / ghc / includes / Stable.h

diff --git a/ghc/includes/Stable.h b/ghc/includes/Stable.h
index 960ac27..ca2e721 100644 (file)
--- a/ghc/includes/Stable.h
+++ b/ghc/includes/Stable.h
@@ -1,12 +1,21 @@
 /* -----------------------------------------------------------------------------
- * $Id: Stable.h,v 1.4 1999/03/02 19:44:16 sof Exp $
  *
- * (c) The GHC Team, 1998-1999
+ * (c) The GHC Team, 1998-2004
  *
- * Stable names and stable pointers
+ * Stable Pointers: A stable pointer is represented as an index into
+ * the stable pointer table in the low BITS_PER_WORD-8 bits with a
+ * weight in the upper 8 bits.
+ *
+ * SUP: StgStablePtr used to be a synonym for StgWord, but stable pointers
+ * are guaranteed to be void* on the C-side, so we have to do some occasional
+ * casting. Size is not a matter, because StgWord is always the same size as
+ * a void*.
  *
  * ---------------------------------------------------------------------------*/
 
+#ifndef STABLE_H
+#define STABLE_H
+
 /* -----------------------------------------------------------------------------
    External C Interface
    -------------------------------------------------------------------------- */
@@ -14,51 +23,44 @@
 extern StgPtr         deRefStablePtr(StgStablePtr stable_ptr);
 extern void           freeStablePtr(StgStablePtr sp);
 extern StgStablePtr   splitStablePtr(StgStablePtr sp);
+extern StgStablePtr   getStablePtr(StgPtr p);
 
 /* -----------------------------------------------------------------------------
    PRIVATE from here.
    -------------------------------------------------------------------------- */
 
-extern StgStablePtr getStablePtr(StgPtr p);
-
 typedef struct { 
   StgPtr  addr;                        /* Haskell object, free list, or NULL */
-  StgWord weight;              /* used for reference counting */
+  StgPtr  old;                 /* old Haskell object, used during GC */
+  StgWord ref;                 /* used for reference counting */
   StgClosure *sn_obj;          /* the StableName object (or NULL) */
 } snEntry;
 
 extern DLL_IMPORT_RTS snEntry *stable_ptr_table;
-extern DLL_IMPORT_RTS snEntry *stable_ptr_free;
 
-extern DLL_IMPORT_RTS unsigned int SPT_size;
+extern void freeStablePtr(StgStablePtr sp);
 
-extern inline StgPtr
-deRefStablePtr(StgStablePtr sp)
+#if defined(__GNUC__)
+# ifndef RTS_STABLE_C
+extern inline
+# endif
+StgPtr deRefStablePtr(StgStablePtr sp)
 {
-  ASSERT(stable_ptr_table[sp & ~STABLEPTR_WEIGHT_MASK].weight > 0);
-  return stable_ptr_table[sp & ~STABLEPTR_WEIGHT_MASK].addr;
+    ASSERT(stable_ptr_table[(StgWord)sp].ref > 0);
+    return stable_ptr_table[(StgWord)sp].addr;
 }
+#else
+/* No support for 'extern inline' */
+extern StgPtr deRefStablePtr(StgStablePtr sp);
+#endif
 
-extern inline void
-freeStablePtr(StgStablePtr sp)
-{
-  StgWord sn = sp & ~STABLEPTR_WEIGHT_MASK;
-  
-  ASSERT(sn < SPT_size
-        && stable_ptr_table[sn].addr != NULL
-        && stable_ptr_table[sn].weight > 0);
-  
-  stable_ptr_table[sn].weight += (sp & STABLEPTR_WEIGHT_MASK) >> STABLEPTR_WEIGHT_SHIFT;
-}
+extern void    initStablePtrTable    ( void );
+extern void    enlargeStablePtrTable ( void );
+extern StgWord lookupStableName      ( StgPtr p );
 
-extern inline StgStablePtr
-splitStablePtr(StgStablePtr sp)
-{
-  /* doesn't need access to the stable pointer table */
-  StgWord weight = (sp & STABLEPTR_WEIGHT_MASK) / 2;
-  return (sp & ~STABLEPTR_WEIGHT_MASK) + weight;
-}
+extern void    markStablePtrTable    ( evac_fn evac );
+extern void    threadStablePtrTable  ( evac_fn evac );
+extern void    gcStablePtrTable      ( void );
+extern void    updateStablePtrTable  ( rtsBool full );
 
-/* No deRefStableName, because the existence of a stable name doesn't
- * guarantee the existence of the object itself.
- */
+#endif