X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/0ed506b0a9c949af9b2f672ac917ecaedca266c0..8ed41a8d8b27bd21b00a4c24af81eecb4637fa1a:/src/xbt/mmalloc/mmalloc.c

diff --git a/src/xbt/mmalloc/mmalloc.c b/src/xbt/mmalloc/mmalloc.c
index e9e8588bf1..355b24c1a3 100644
--- a/src/xbt/mmalloc/mmalloc.c
+++ b/src/xbt/mmalloc/mmalloc.c
@@ -16,18 +16,25 @@
 
 /* Prototypes for local functions */
 
-static int initialize(struct mdesc *mdp);
-static void *morecore(struct mdesc *mdp, size_t size);
-static void *align(struct mdesc *mdp, size_t size);
-
-/* Aligned allocation.  */
+static int initialize(xbt_mheap_t mdp);
+static void *register_morecore(xbt_mheap_t mdp, size_t size);
+static void *align(xbt_mheap_t mdp, size_t size);
 
+/* Allocation aligned on block boundary */
 static void *align(struct mdesc *mdp, size_t size)
 {
   void *result;
   unsigned long int adj;
 
   result = mmorecore(mdp, size);
+
+  /* if this reservation does not fill up the last block of our resa,
+   * complete the reservation by also asking for the full lastest block.
+   *
+   * Also, the returned block is aligned to the end of block (but I've
+   * no fucking idea of why, actually -- http://abstrusegoose.com/432 --
+   * but not doing so seems to lead to issues).
+   */
   adj = RESIDUAL(result, BLOCKSIZE);
   if (adj != 0) {
     adj = BLOCKSIZE - adj;
@@ -37,9 +44,9 @@ static void *align(struct mdesc *mdp, size_t size)
   return (result);
 }
 
-/* Set everything up and remember that we have.  */
-
-static int initialize(struct mdesc *mdp)
+/* Finish the initialization of the mheap. If we want to inline it
+ * properly, we need to make the align function publicly visible, too  */
+static int initialize(xbt_mheap_t mdp)
 {
   mdp->heapsize = HEAP / BLOCKSIZE;
   mdp->heapinfo = (malloc_info *)
@@ -56,10 +63,9 @@ static int initialize(struct mdesc *mdp)
   return (1);
 }
 
-/* Get neatly aligned memory, initializing or
-   growing the heap info table as necessary. */
-
-static void *morecore(struct mdesc *mdp, size_t size)
+/* Get neatly aligned memory from the low level layers, and register it
+ * into the heap info table as necessary. */
+static void *register_morecore(struct mdesc *mdp, size_t size)
 {
   void *result;
   malloc_info *newinfo, *oldinfo;
@@ -70,26 +76,25 @@ static void *morecore(struct mdesc *mdp, size_t size)
     return (NULL);
   }
 
-  /* Check if we need to grow the info table.  */
+  /* Check if we need to grow the info table (in a multiplicative manner)  */
   if ((size_t) BLOCK((char *) result + size) > mdp->heapsize) {
+
     newsize = mdp->heapsize;
-    while ((size_t) BLOCK((char *) result + size) > newsize) {
+    while ((size_t) BLOCK((char *) result + size) > newsize)
       newsize *= 2;
-    }
-    newinfo = (malloc_info *) align(mdp, newsize * sizeof(malloc_info));
-    if (newinfo == NULL) {
-      mmorecore(mdp, -size);
-      return (NULL);
-    }
-    memset((void *) newinfo, 0, newsize * sizeof(malloc_info));
-    memcpy((void *) newinfo, (void *) mdp->heapinfo,
-           mdp->heapsize * sizeof(malloc_info));
+
+    /* Copy old info into new location */
     oldinfo = mdp->heapinfo;
+    newinfo = (malloc_info *) align(mdp, newsize * sizeof(malloc_info));
+    memset(newinfo, 0, newsize * sizeof(malloc_info));
+    memcpy(newinfo, oldinfo, mdp->heapsize * sizeof(malloc_info));
+    mdp->heapinfo = newinfo;
+
+    /* mark the space previously occupied by the block info as free by first marking it
+     * as occupied in the regular way, and then freing it */
     newinfo[BLOCK(oldinfo)].busy.type = 0;
-    newinfo[BLOCK(oldinfo)].busy.info.block.size
-        = BLOCKIFY(mdp->heapsize * sizeof(malloc_info));
+    newinfo[BLOCK(oldinfo)].busy.info.block.size = BLOCKIFY(mdp->heapsize * sizeof(malloc_info));
     newinfo[BLOCK(oldinfo)].busy.info.block.busy_size = size;
-    mdp->heapinfo = newinfo;
     __mmalloc_free(mdp, (void *) oldinfo);
     mdp->heapsize = newsize;
   }
@@ -100,9 +105,8 @@ static void *morecore(struct mdesc *mdp, size_t size)
 
 /* Allocate memory from the heap.  */
 
-void *mmalloc(void *md, size_t size)
+void *mmalloc(xbt_mheap_t mdp, size_t size)
 {
-  struct mdesc *mdp;
   void *result;
   size_t block, blocks, lastblocks, start;
   register size_t i;
@@ -115,7 +119,6 @@ void *mmalloc(void *md, size_t size)
   if (size == 0)
     size = 1;
 
-  mdp = MD_TO_MDP(md);
 //  printf("(%s) Mallocing %d bytes on %p (default: %p)...",xbt_thread_self_name(),size,mdp,__mmalloc_default_mdp);fflush(stdout);
 
   if (!(mdp->flags & MMALLOC_INITIALIZED)) {
@@ -156,16 +159,11 @@ void *mmalloc(void *md, size_t size)
             RESIDUAL(next->next, BLOCKSIZE) >> log;
       }
 
-      /* Update the statistics.  */
-      mdp->heapstats.chunks_used++;
-      mdp->heapstats.bytes_used += 1 << log;
-      mdp->heapstats.chunks_free--;
-      mdp->heapstats.bytes_free -= 1 << log;
     } else {
       /* No free fragments of the desired size, so get a new block
          and break it into fragments, returning the first.  */
       //printf("(%s) No free fragment...",xbt_thread_self_name());
-      result = mmalloc(md, BLOCKSIZE);
+      result = mmalloc(mdp, BLOCKSIZE);
       //printf("(%s) Fragment: %p...",xbt_thread_self_name(),result);
       if (result == NULL) {
         return (NULL);
@@ -187,10 +185,6 @@ void *mmalloc(void *md, size_t size)
       mdp->heapinfo[block].busy.type = log;
       mdp->heapinfo[block].busy.info.frag.nfree = i - 1;
       mdp->heapinfo[block].busy.info.frag.first = i - 1;
-
-      mdp->heapstats.chunks_free += (BLOCKSIZE >> log) - 1;
-      mdp->heapstats.bytes_free += BLOCKSIZE - (1 << log);
-      mdp->heapstats.bytes_used -= BLOCKSIZE - (1 << log);
     }
   } else {
     /* Large allocation to receive one or more blocks.
@@ -210,17 +204,16 @@ void *mmalloc(void *md, size_t size)
         if (mdp->heaplimit != 0 &&
             block + lastblocks == mdp->heaplimit &&
             mmorecore(mdp, 0) == ADDRESS(block + lastblocks) &&
-            (morecore(mdp, (blocks - lastblocks) * BLOCKSIZE)) != NULL) {
+            (register_morecore(mdp, (blocks - lastblocks) * BLOCKSIZE)) != NULL) {
           /* Which block we are extending (the `final free
              block' referred to above) might have changed, if
              it got combined with a freed info table.  */
           block = mdp->heapinfo[0].free.prev;
 
           mdp->heapinfo[block].free.size += (blocks - lastblocks);
-          mdp->heapstats.bytes_free += (blocks - lastblocks) * BLOCKSIZE;
           continue;
         }
-        result = morecore(mdp, blocks * BLOCKSIZE);
+        result = register_morecore(mdp, blocks * BLOCKSIZE);
         if (result == NULL) {
           return (NULL);
         }
@@ -228,8 +221,6 @@ void *mmalloc(void *md, size_t size)
         mdp->heapinfo[block].busy.type = 0;
         mdp->heapinfo[block].busy.info.block.size = blocks;
 	mdp->heapinfo[block].busy.info.block.busy_size = size;
-        mdp->heapstats.chunks_used++;
-        mdp->heapstats.bytes_used += blocks * BLOCKSIZE;
         return (result);
       }
     }
@@ -256,15 +247,11 @@ void *mmalloc(void *md, size_t size)
           = mdp->heapinfo[block].free.prev;
       mdp->heapinfo[mdp->heapinfo[block].free.prev].free.next
           = mdp->heapindex = mdp->heapinfo[block].free.next;
-      mdp->heapstats.chunks_free--;
     }
 
     mdp->heapinfo[block].busy.type = 0;
     mdp->heapinfo[block].busy.info.block.size = blocks;
     mdp->heapinfo[block].busy.info.block.busy_size = size;
-    mdp->heapstats.chunks_used++;
-    mdp->heapstats.bytes_used += blocks * BLOCKSIZE;
-    mdp->heapstats.bytes_free -= blocks * BLOCKSIZE;
   }
   //printf("(%s) Done mallocing. Result is %p\n",xbt_thread_self_name(),result);fflush(stdout);
   return (result);