[project @ 2001-08-08 10:50:36 by simonmar]

[ghc-hetmet.git] / ghc / rts / BlockAlloc.c

diff --git a/ghc/rts/BlockAlloc.c b/ghc/rts/BlockAlloc.c
index 26f2a60..6186671 100644 (file)
--- a/ghc/rts/BlockAlloc.c
+++ b/ghc/rts/BlockAlloc.c
@@ -1,6 +1,8 @@
 /* -----------------------------------------------------------------------------
- * $Id: BlockAlloc.c,v 1.3 1999/01/13 17:25:37 simonm Exp $
+ * $Id: BlockAlloc.c,v 1.9 2001/07/23 17:23:19 simonmar Exp $
  *
+ * (c) The GHC Team 1998-2000
+ * 
  * The block allocator and free list manager.
  *
  * This is the architecture independent part of the block allocator.
@@ -61,6 +63,8 @@ allocGroup(nat n)
   void *mblock;
   bdescr *bd, **last;
 
+  ASSERT(n != 0);
+
   if (n > BLOCKS_PER_MBLOCK) {
     return allocMegaGroup(BLOCKS_TO_MBLOCKS(n));
   }
@@ -71,6 +75,9 @@ allocGroup(nat n)
       *last = bd->link;
       /* no initialisation necessary - this is already a
        * self-contained block group. */
+#ifdef DEBUG
+      bd->free = bd->start;    /* block isn't free now */
+#endif
       return bd;
     }
     if (bd->blocks >  n) {     /* block too big... */
@@ -86,8 +93,10 @@ allocGroup(nat n)
   initMBlock(mblock);          /* initialise the start fields */
   bd = FIRST_BDESCR(mblock);
   initGroup(n,bd);             /* we know the group will fit */
-  initGroup(BLOCKS_PER_MBLOCK-n, bd+n);
-  freeGroup(bd+n);             /* add the rest on to the free list */
+  if (n < BLOCKS_PER_MBLOCK) {
+    initGroup(BLOCKS_PER_MBLOCK-n, bd+n);
+    freeGroup(bd+n);           /* add the rest on to the free list */
+  }
   return bd;
 }
 
@@ -124,7 +133,9 @@ allocMegaGroup(nat n)
 
     if (bd->blocks == BLOCKS_PER_MBLOCK) {     /* whole megablock found */
 
-      if (grp_start == NULL) { /* is it the first one we've found? */
+      /* is it the first one we've found or a non-contiguous megablock? */
+      if (grp_start == NULL ||
+          bd->start != last->start + MBLOCK_SIZE/sizeof(W_)) {
        grp_start = bd;
        grp_prev  = last;
        mbs_found = 1;
@@ -213,7 +224,7 @@ freeGroup(bdescr *p)
 #ifdef DEBUG
   p->free = (void *)-1;  /* indicates that this block is free */
   p->step = NULL;
-  p->gen  = NULL;
+  p->gen_no = 0;
   /* fill the block group with garbage if sanity checking is on */
   IF_DEBUG(sanity,memset(p->start, 0xaa, p->blocks * BLOCK_SIZE));
 #endif