/* -----------------------------------------------------------------------------
- * $Id: Storage.c,v 1.32 2001/01/16 12:02:04 simonmar Exp $
+ * $Id: Storage.c,v 1.35 2001/01/31 11:04:29 simonmar Exp $
*
* (c) The GHC Team, 1998-1999
*
/* -----------------------------------------------------------------------------
CAF management.
+
+ The entry code for every CAF does the following:
+
+ - builds a CAF_BLACKHOLE in the heap
+ - pushes an update frame pointing to the CAF_BLACKHOLE
+ - invokes UPD_CAF(), which:
+ - calls newCaf, below
+ - updates the CAF with a static indirection to the CAF_BLACKHOLE
+
+ Why do we build a BLACKHOLE in the heap rather than just updating
+ the thunk directly? It's so that we only need one kind of update
+ frame - otherwise we'd need a static version of the update frame too.
+
+ newCaf() does the following:
+
+ - it puts the CAF on the oldest generation's mut-once list.
+ This is so that we can treat the CAF as a root when collecting
+ younger generations.
+
+ For GHCI, we have additional requirements when dealing with CAFs:
+
+ - we must *retain* all dynamically-loaded CAFs ever entered,
+ just in case we need them again.
+ - we must be able to *revert* CAFs that have been evaluated, to
+ their pre-evaluated form.
+
+ To do this, we use an additional CAF list. When newCaf() is
+ called on a dynamically-loaded CAF, we add it to the CAF list
+ instead of the old-generation mutable list, and save away its
+ old info pointer (in caf->saved_info) for later reversion.
+
+ To revert all the CAFs, we traverse the CAF list and reset the
+ info pointer to caf->saved_info, then throw away the CAF list.
+ (see GC.c:revertCAFs()).
+
+ -- SDM 29/1/01
+
-------------------------------------------------------------------------- */
void
*/
ACQUIRE_LOCK(&sm_mutex);
+#ifdef GHCI
+ if (is_dynamically_loaded_rwdata_ptr((StgPtr)caf)) {
+ ((StgIndStatic *)caf)->saved_info = (StgInfoTable *)caf->header.info;
+ ((StgIndStatic *)caf)->static_link = caf_list;
+ caf_list = caf;
+ } else {
+ ((StgIndStatic *)caf)->saved_info = NULL;
+ ((StgMutClosure *)caf)->mut_link = oldest_gen->mut_once_list;
+ oldest_gen->mut_once_list = (StgMutClosure *)caf;
+ }
+#else
ASSERT( ((StgMutClosure*)caf)->mut_link == NULL );
((StgMutClosure *)caf)->mut_link = oldest_gen->mut_once_list;
oldest_gen->mut_once_list = (StgMutClosure *)caf;
-
-#ifdef INTERPRETER
- /* If we're Hugs, we also have to put it in the CAF table, so that
- the CAF can be reverted. When reverting, CAFs created by compiled
- code are recorded in the CAF table, which lives outside the
- heap, in mallocville. CAFs created by interpreted code are
- chained together via the link fields in StgCAFs, and are not
- recorded in the CAF table.
- */
- ASSERT( get_itbl(caf)->type == THUNK_STATIC );
- addToECafTable ( caf, get_itbl(caf) );
#endif
RELEASE_LOCK(&sm_mutex);
}
-#ifdef INTERPRETER
-void
-newCAF_made_by_Hugs(StgCAF* caf)
-{
- ACQUIRE_LOCK(&sm_mutex);
-
- ASSERT( get_itbl(caf)->type == CAF_ENTERED );
- recordOldToNewPtrs((StgMutClosure*)caf);
- caf->link = ecafList;
- ecafList = caf->link;
-
- RELEASE_LOCK(&sm_mutex);
-}
-#endif
-
-#ifdef INTERPRETER
-/* These initialisations are critical for correct operation
- on the first call of addToECafTable.
-*/
-StgCAF* ecafList = END_ECAF_LIST;
-StgCAFTabEntry* ecafTable = NULL;
-StgInt usedECafTable = 0;
-StgInt sizeECafTable = 0;
-
-
-void clearECafTable ( void )
-{
- usedECafTable = 0;
-}
-
-void addToECafTable ( StgClosure* closure, StgInfoTable* origItbl )
-{
- StgInt i;
- StgCAFTabEntry* et2;
- if (usedECafTable == sizeECafTable) {
- /* Make the initial table size be 8 */
- sizeECafTable *= 2;
- if (sizeECafTable == 0) sizeECafTable = 8;
- et2 = stgMallocBytes (
- sizeECafTable * sizeof(StgCAFTabEntry),
- "addToECafTable" );
- for (i = 0; i < usedECafTable; i++)
- et2[i] = ecafTable[i];
- if (ecafTable) free(ecafTable);
- ecafTable = et2;
- }
- ecafTable[usedECafTable].closure = closure;
- ecafTable[usedECafTable].origItbl = origItbl;
- usedECafTable++;
-}
-#endif
-
/* -----------------------------------------------------------------------------
Nursery management.
-------------------------------------------------------------------------- */