X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/1086dc93eea1d88ee42e9317fda2278c784d0b60..c59fb90ea83ce58355bc388b1a5ebaef96420806:/src/xbt/mmalloc/mfree.c

diff --git a/src/xbt/mmalloc/mfree.c b/src/xbt/mmalloc/mfree.c
index ff89699679..e9031ebdf6 100644
--- a/src/xbt/mmalloc/mfree.c
+++ b/src/xbt/mmalloc/mfree.c
@@ -11,159 +11,187 @@
  * under the terms of the license (GNU LGPL) which comes with this package. */
 
 #include "mmprivate.h"
+#include "xbt/ex.h"
 
 /* Return memory to the heap.
    Like `mfree' but don't call a mfree_hook if there is one.  */
 
-void __mmalloc_free(struct mdesc *mdp, void *ptr)
+/* Return memory to the heap.  */
+void mfree(struct mdesc *mdp, void *ptr)
 {
   int type;
-  size_t block;
+  size_t block, frag_nb;
   register size_t i;
-  struct list *prev, *next;
+  int it;
+
+  mmalloc_paranoia(mdp);
+//  fprintf(stderr,"free(%p)\n",ptr);
+
+  if (ptr == NULL)
+    return;
 
   block = BLOCK(ptr);
 
   if ((char *) ptr < (char *) mdp->heapbase || block > mdp->heapsize) {
-    printf("Ouch, this pointer is not mine. I refuse to free it.\n");
-    return;
+    fprintf(stderr,"Ouch, this pointer is not mine. I refuse to free it. I refuse it to death!!\n");
+    abort();
   }
 
+  type = mdp->heapinfo[block].type;
 
-  type = mdp->heapinfo[block].busy.type;
   switch (type) {
+  case -1: /* Already free */
+    UNLOCK(mdp);
+    THROWF(system_error, 0, "Asked to free a fragment in a block that is already free. I'm puzzled\n");
+    break;
+    
   case 0:
+    /* Get as many statistics as early as we can.  */
+    mdp -> heapstats.chunks_used--;
+    mdp -> heapstats.bytes_used -=
+      mdp -> heapinfo[block].busy_block.size * BLOCKSIZE;
+    mdp -> heapstats.bytes_free +=
+      mdp -> heapinfo[block].busy_block.size * BLOCKSIZE;
+
     /* Find the free cluster previous to this one in the free list.
        Start searching at the last block referenced; this may benefit
        programs with locality of allocation.  */
     i = mdp->heapindex;
     if (i > block) {
       while (i > block) {
-        i = mdp->heapinfo[i].free.prev;
+        i = mdp->heapinfo[i].free_block.prev;
       }
     } else {
       do {
-        i = mdp->heapinfo[i].free.next;
+        i = mdp->heapinfo[i].free_block.next;
       }
       while ((i != 0) && (i < block));
-      i = mdp->heapinfo[i].free.prev;
+      i = mdp->heapinfo[i].free_block.prev;
     }
 
     /* Determine how to link this block into the free list.  */
-    if (block == i + mdp->heapinfo[i].free.size) {
+    if (block == i + mdp->heapinfo[i].free_block.size) {
+
       /* Coalesce this block with its predecessor.  */
-      mdp->heapinfo[i].free.size += mdp->heapinfo[block].busy.info.block.size;
+      mdp->heapinfo[i].free_block.size += mdp->heapinfo[block].busy_block.size;
+      /* Mark all my ex-blocks as free */
+      for (it=0; it<mdp->heapinfo[block].busy_block.size; it++) {
+        if (mdp->heapinfo[block+it].type <0) {
+          fprintf(stderr,"Internal Error: Asked to free a block already marked as free (block=%lu it=%d type=%lu). Please report this bug.\n",
+                  (unsigned long)block,it,(unsigned long)mdp->heapinfo[block].type);
+          abort();
+        }
+        mdp->heapinfo[block+it].type = -1;
+      }
+
       block = i;
     } else {
+      //fprintf(stderr,"Free block %d to %d (as a new chunck)\n",block,block+mdp->heapinfo[block].busy_block.size);
       /* Really link this block back into the free list.  */
-      mdp->heapinfo[block].free.size = mdp->heapinfo[block].busy.info.block.size;
-      mdp->heapinfo[block].free.next = mdp->heapinfo[i].free.next;
-      mdp->heapinfo[block].free.prev = i;
-      mdp->heapinfo[i].free.next = block;
-      mdp->heapinfo[mdp->heapinfo[block].free.next].free.prev = block;
+      mdp->heapinfo[block].free_block.size = mdp->heapinfo[block].busy_block.size;
+      mdp->heapinfo[block].free_block.next = mdp->heapinfo[i].free_block.next;
+      mdp->heapinfo[block].free_block.prev = i;
+      mdp->heapinfo[i].free_block.next = block;
+      mdp->heapinfo[mdp->heapinfo[block].free_block.next].free_block.prev = block;
+      mdp -> heapstats.chunks_free++;
+      /* Mark all my ex-blocks as free */
+      for (it=0; it<mdp->heapinfo[block].free_block.size; it++) {
+        if (mdp->heapinfo[block+it].type <0) {
+          fprintf(stderr,"Internal error: Asked to free a block already marked as free (block=%lu it=%d/%lu type=%lu). Please report this bug.\n",
+                  (unsigned long)block,it,(unsigned long)mdp->heapinfo[block].free_block.size,(unsigned long)mdp->heapinfo[block].type);
+          abort();
+        }
+        mdp->heapinfo[block+it].type = -1;
+      }
     }
 
     /* Now that the block is linked in, see if we can coalesce it
        with its successor (by deleting its successor from the list
        and adding in its size).  */
-    if (block + mdp->heapinfo[block].free.size ==
-        mdp->heapinfo[block].free.next) {
-      mdp->heapinfo[block].free.size
-          += mdp->heapinfo[mdp->heapinfo[block].free.next].free.size;
-      mdp->heapinfo[block].free.next
-          = mdp->heapinfo[mdp->heapinfo[block].free.next].free.next;
-      mdp->heapinfo[mdp->heapinfo[block].free.next].free.prev = block;
+    if (block + mdp->heapinfo[block].free_block.size ==
+        mdp->heapinfo[block].free_block.next) {
+      mdp->heapinfo[block].free_block.size
+        += mdp->heapinfo[mdp->heapinfo[block].free_block.next].free_block.size;
+      mdp->heapinfo[block].free_block.next
+        = mdp->heapinfo[mdp->heapinfo[block].free_block.next].free_block.next;
+      mdp->heapinfo[mdp->heapinfo[block].free_block.next].free_block.prev = block;
+      mdp -> heapstats.chunks_free--;
     }
 
     /* Now see if we can return stuff to the system.  */
     /*    blocks = mdp -> heapinfo[block].free.size;
-       if (blocks >= FINAL_FREE_BLOCKS && block + blocks == mdp -> heaplimit
-       && mdp -> morecore (mdp, 0) == ADDRESS (block + blocks))
-       {
-       register size_t bytes = blocks * BLOCKSIZE;
-       mdp -> heaplimit -= blocks;
-       mdp -> morecore (mdp, -bytes);
-       mdp -> heapinfo[mdp -> heapinfo[block].free.prev].free.next
-       = mdp -> heapinfo[block].free.next;
-       mdp -> heapinfo[mdp -> heapinfo[block].free.next].free.prev
-       = mdp -> heapinfo[block].free.prev;
-       block = mdp -> heapinfo[block].free.prev;
-       mdp -> heapstats.chunks_free--;
-       mdp -> heapstats.bytes_free -= bytes;
-       } */
-
-    /* Set the next search to begin at this block.  */
+          if (blocks >= FINAL_FREE_BLOCKS && block + blocks == mdp -> heaplimit
+          && mdp -> morecore (mdp, 0) == ADDRESS (block + blocks))
+          {
+          register size_t bytes = blocks * BLOCKSIZE;
+          mdp -> heaplimit -= blocks;
+          mdp -> morecore (mdp, -bytes);
+          mdp -> heapinfo[mdp -> heapinfo[block].free.prev].free.next
+          = mdp -> heapinfo[block].free.next;
+          mdp -> heapinfo[mdp -> heapinfo[block].free.next].free.prev
+          = mdp -> heapinfo[block].free.prev;
+          block = mdp -> heapinfo[block].free.prev;
+          mdp -> heapstats.chunks_free--;
+          mdp -> heapstats.bytes_free -= bytes;
+          } */
+
+    /* Set the next search to begin at this block.  
+       This is probably important to the trick where realloc returns the block to 
+       the system before reasking for the same block with a bigger size.  */
     mdp->heapindex = block;
     break;
 
   default:
-    /* Get the address of the first free fragment in this block.  */
-    prev = (struct list *)
-        ((char *) ADDRESS(block) +
-         (mdp->heapinfo[block].busy.info.frag.first << type));
+    /* Do some of the statistics.  */
+    mdp -> heapstats.chunks_used--;
+    mdp -> heapstats.bytes_used -= 1 << type;
+    mdp -> heapstats.chunks_free++;
+    mdp -> heapstats.bytes_free += 1 << type;
 
-    if (mdp->heapinfo[block].busy.info.frag.nfree ==
-        (BLOCKSIZE >> type) - 1) {
-      /* If all fragments of this block are free, remove them
-         from the fragment list and free the whole block.  */
-      next = prev;
-      for (i = 1; i < (size_t) (BLOCKSIZE >> type); ++i) {
-        next = next->next;
-      }
-      prev->prev->next = next;
-      if (next != NULL) {
-        next->prev = prev->prev;
-      }
-      mdp->heapinfo[block].busy.type = 0;
-      mdp->heapinfo[block].busy.info.block.size = 1;
-      mdp->heapinfo[block].busy.info.block.busy_size = 0;
+    frag_nb = RESIDUAL(ptr, BLOCKSIZE) >> type;
+
+    if( mdp->heapinfo[block].busy_frag.frag_size[frag_nb] == -1){
+      UNLOCK(mdp);
+      THROWF(system_error, 0, "Asked to free a fragment that is already free. I'm puzzled\n");
+    }
 
+    /* Set size used in the fragment to -1 */
+    mdp->heapinfo[block].busy_frag.frag_size[frag_nb] = -1;
+    mdp->heapinfo[block].busy_frag.ignore[frag_nb] = 0;
+    
+//    fprintf(stderr,"nfree:%zu capa:%d\n", mdp->heapinfo[block].busy_frag.nfree,(BLOCKSIZE >> type));
+    if (mdp->heapinfo[block].busy_frag.nfree ==
+        (BLOCKSIZE >> type) - 1) {
+      /* If all fragments of this block are free, remove this block from its swag and free the whole block.  */
+      xbt_swag_remove(&mdp->heapinfo[block],&mdp->fraghead[type]);
+
+      /* pretend that this block is used and free it so that it gets properly coalesced with adjacent free blocks */
+      mdp->heapinfo[block].type = 0;
+      mdp->heapinfo[block].busy_block.size = 1;
+      mdp->heapinfo[block].busy_block.busy_size = 0;
+      mdp->heapinfo[block].busy_block.ignore = 0;
+            
+      /* Keep the statistics accurate.  */
+      mdp -> heapstats.chunks_used++;
+      mdp -> heapstats.bytes_used += BLOCKSIZE;
+      mdp -> heapstats.chunks_free -= BLOCKSIZE >> type;
+      mdp -> heapstats.bytes_free -= BLOCKSIZE;
+      
       mfree((void *) mdp, (void *) ADDRESS(block));
-    } else if (mdp->heapinfo[block].busy.info.frag.nfree != 0) {
-      /* If some fragments of this block are free, link this
-         fragment into the fragment list after the first free
-         fragment of this block. */
-      next = (struct list *) ptr;
-      next->next = prev->next;
-      next->prev = prev;
-      prev->next = next;
-      if (next->next != NULL) {
-        next->next->prev = next;
-      }
-      ++mdp->heapinfo[block].busy.info.frag.nfree;
+    } else if (mdp->heapinfo[block].busy_frag.nfree != 0) {
+      /* If some fragments of this block are free, you know what? I'm already happy. */
+      ++mdp->heapinfo[block].busy_frag.nfree;
     } else {
-      /* No fragments of this block are free, so link this
-         fragment into the fragment list and announce that
-         it is the first free fragment of this block. */
-      prev = (struct list *) ptr;
-      mdp->heapinfo[block].busy.info.frag.nfree = 1;
-      mdp->heapinfo[block].busy.info.frag.first =
-          RESIDUAL(ptr, BLOCKSIZE) >> type;
-      prev->next = mdp->fraghead[type].next;
-      prev->prev = &mdp->fraghead[type];
-      prev->prev->next = prev;
-      if (prev->next != NULL) {
-        prev->next->prev = prev;
-      }
+      /* No fragments of this block were free before the one we just released,
+       * so add this block to the swag and announce that
+       it is the first free fragment of this block. */
+      mdp->heapinfo[block].busy_frag.nfree = 1;
+      mdp->heapinfo[block].freehook.prev = NULL;
+      mdp->heapinfo[block].freehook.next = NULL;
+
+      xbt_swag_insert(&mdp->heapinfo[block],&mdp->fraghead[type]);
     }
     break;
   }
 }
 
-/* Return memory to the heap.  */
-
-void mfree(xbt_mheap_t mdp, void *ptr)
-{
-  register struct alignlist *l;
-
-  if (ptr != NULL) {
-    for (l = mdp->aligned_blocks; l != NULL; l = l->next) {
-      if (l->aligned == ptr) {
-        l->aligned = NULL;      /* Mark the slot in the list as free. */
-        ptr = l->exact;
-        break;
-      }
-    }
-    __mmalloc_free(mdp, ptr);
-  }
-}