X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/4c04d8355923f8323a1a3195fe3b73ac08b984ea..ea39fd08c260e7faa92334952d4acd37e3892b6c:/src/xbt/mmalloc/mmalloc.c

diff --git a/src/xbt/mmalloc/mmalloc.c b/src/xbt/mmalloc/mmalloc.c
index c717fe58e7..95c5db6671 100644
--- a/src/xbt/mmalloc/mmalloc.c
+++ b/src/xbt/mmalloc/mmalloc.c
@@ -10,295 +10,319 @@
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
 
-#include <string.h>	/* Prototypes for memcpy, memmove, memset, etc */
+#include <string.h>             /* Prototypes for memcpy, memmove, memset, etc */
 #include <stdio.h>
 #include "mmprivate.h"
 
 /* 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);
+static void 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);
 
-/* Aligned allocation.  */
-
-static void* align (struct mdesc *mdp, size_t size) {
-  void* result;
+/* Allocation aligned on block boundary.
+ *
+ * It never returns NULL, but dies verbosely on error.
+ */
+static void *align(struct mdesc *mdp, size_t size)
+{
+  void *result;
   unsigned long int adj;
 
-  result = mdp -> morecore (mdp, size);
-  adj = RESIDUAL (result, BLOCKSIZE);
-  if (adj != 0)
-  {
+  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;
-    mdp -> morecore (mdp, adj);
-    result = (char*) result + adj;
+    mmorecore(mdp, adj);
+    result = (char *) result + adj;
   }
   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 void initialize(xbt_mheap_t mdp)
 {
-  mdp -> heapsize = HEAP / BLOCKSIZE;
-  mdp -> heapinfo = (malloc_info *) 
-        align (mdp, mdp -> heapsize * sizeof (malloc_info));
-  if (mdp -> heapinfo == NULL)
-  {
-    return (0);
+  int i;
+  malloc_info mi; /* to compute the offset of the swag hook */
+
+  mdp->heapsize = HEAP / BLOCKSIZE;
+  mdp->heapinfo = (malloc_info *)
+    align(mdp, mdp->heapsize * sizeof(malloc_info));
+
+  memset((void *) mdp->heapinfo, 0, mdp->heapsize * sizeof(malloc_info));
+  mdp->heapinfo[0].type=-1;
+  mdp->heapinfo[0].free_block.size = 0;
+  mdp->heapinfo[0].free_block.next = mdp->heapinfo[0].free_block.prev = 0;
+  mdp->heapindex = 0;
+  mdp->heapbase = (void *) mdp->heapinfo;
+  mdp->flags |= MMALLOC_INITIALIZED;
+
+  for (i=0;i<BLOCKLOG;i++) {
+      xbt_swag_init(&(mdp->fraghead[i]),
+                    xbt_swag_offset(mi, freehook));
   }
-  memset ((void*)mdp -> heapinfo, 0, mdp -> heapsize * sizeof (malloc_info));
-  mdp -> heapinfo[0].free.size = 0;
-  mdp -> heapinfo[0].free.next = mdp -> heapinfo[0].free.prev = 0;
-  mdp -> heapindex = 0;
-  mdp -> heapbase = (void*) mdp -> heapinfo;
-  mdp -> flags |= MMALLOC_INITIALIZED;
-  return (1);
 }
 
-/* Get neatly aligned memory, initializing or
-   growing the heap info table as necessary. */
+#define update_hook(a,offset) do { if (a) { a = ((char*)a +(offset));} }while(0)
 
-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;
+  int i;
+  void *result;
   malloc_info *newinfo, *oldinfo;
   size_t newsize;
 
-  result = align (mdp, size);
-  if (result == NULL)
-  {
-    return (NULL);
-  }
+  result = align(mdp, size); // Never returns NULL
+
+  /* Check if we need to grow the info table (in a multiplicative manner)  */
+  if ((size_t) BLOCK((char *) result + size) > mdp->heapsize) {
+    int it;
 
-  /* Check if we need to grow the info table.  */
-  if ((size_t) BLOCK ((char*) result + size) > mdp -> heapsize)
-  {
-    newsize = mdp -> heapsize;
-    while ((size_t) BLOCK ((char*) result + size) > newsize)
-    {
+    newsize = mdp->heapsize;
+    while ((size_t) BLOCK((char *) result + size) > newsize)
       newsize *= 2;
+
+    /* 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));
+
+    /* Update the swag of busy blocks containing free fragments by applying the offset to all swag_hooks. Yeah. My hand is right in the fan and I still type */
+    size_t offset=((char*)newinfo)-((char*)oldinfo);
+
+    for (i=1/*first element of heapinfo describes the mdesc area*/;
+         i<mdp->heaplimit;
+         i++) {
+      update_hook(newinfo[i].freehook.next,offset);
+      update_hook(newinfo[i].freehook.prev,offset);
     }
-    newinfo = (malloc_info *) align (mdp, newsize * sizeof (malloc_info));
-    if (newinfo == NULL)
-    {
-      mdp -> morecore (mdp, -size);
-      return (NULL);
+    // also update the starting points of the swag
+    for (i=0;i<BLOCKLOG;i++) {
+      update_hook(mdp->fraghead[i].head,offset);
+      update_hook(mdp->fraghead[i].tail,offset);
     }
-    memset ((void*) newinfo, 0, newsize * sizeof (malloc_info));
-    memcpy ((void*) newinfo, (void*) mdp -> heapinfo,
-        mdp -> heapsize * sizeof (malloc_info));
-    oldinfo = mdp -> heapinfo;
-    newinfo[BLOCK (oldinfo)].busy.type = 0;
-    newinfo[BLOCK (oldinfo)].busy.info.size
-    = BLOCKIFY (mdp -> heapsize * sizeof (malloc_info));
-    mdp -> heapinfo = newinfo;
-    __mmalloc_free (mdp, (void*)oldinfo);
-    mdp -> heapsize = newsize;
+    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 */
+    for (it=0; it<BLOCKIFY(mdp->heapsize * sizeof(malloc_info)); it++)
+      newinfo[BLOCK(oldinfo)+it].type = 0;
+
+    newinfo[BLOCK(oldinfo)].busy_block.size = BLOCKIFY(mdp->heapsize * sizeof(malloc_info));
+    newinfo[BLOCK(oldinfo)].busy_block.busy_size = size;
+    newinfo[BLOCK(oldinfo)].busy_block.bt_size = 0;// FIXME setup the backtrace
+    mfree(mdp, (void *) oldinfo);
+    mdp->heapsize = newsize;
   }
 
-  mdp -> heaplimit = BLOCK ((char*) result + size);
+  mdp->heaplimit = BLOCK((char *) result + size);
   return (result);
 }
+#undef update_hook
 
 /* Allocate memory from the heap.  */
-
-void* mmalloc (void *md, size_t size) {
-  struct mdesc *mdp;
-  void* result;
+void *mmalloc(xbt_mheap_t mdp, size_t size) {
+  void *res= mmalloc_no_memset(mdp,size);
+//  fprintf(stderr,"malloc(%zu)~>%p\n",size,res);
+  memset(res,0,size);
+  return res;
+}
+/* Spliting mmalloc this way is mandated by a trick in mrealloc, that gives
+   back the memory of big blocks to the system before reallocating them: we don't
+   want to loose the beginning of the area when this happens */
+void *mmalloc_no_memset(xbt_mheap_t mdp, size_t size)
+{
+  void *result;
   size_t block, blocks, lastblocks, start;
   register size_t i;
-  struct list *next;
   register size_t log;
+  int it;
 
-  if (size == 0)
-    return (NULL);
+  size_t requested_size = size; // The amount of memory requested by user, for real
 
-  mdp = MD_TO_MDP (md);
-  LOCK(mdp);
-  printf("(%s) Mallocing %d bytes on %p (default: %p)...",xbt_thread_self_name(),size,mdp,__mmalloc_default_mdp);fflush(stdout);
+  /* Work even if the user was stupid enough to ask a ridicullously small block (even 0-length),
+   *    ie return a valid block that can be realloced and freed.
+   * glibc malloc does not use this trick but return a constant pointer, but we need to enlist the free fragments later on.
+   */
+  if (size < SMALLEST_POSSIBLE_MALLOC)
+    size = SMALLEST_POSSIBLE_MALLOC;
 
+  //  printf("(%s) Mallocing %d bytes on %p (default: %p)...",xbt_thread_self_name(),size,mdp,__mmalloc_default_mdp);fflush(stdout);
 
-  if (mdp -> mmalloc_hook != NULL) {
-    void * res = ((*mdp -> mmalloc_hook) (md, size));
-    UNLOCK(mdp);
-    return res;
-  }
-
-  if (!(mdp -> flags & MMALLOC_INITIALIZED)) {
-    if (!initialize (mdp)) {
-      UNLOCK(mdp);
-      return (NULL);
-    }
-  }
+  if (!(mdp->flags & MMALLOC_INITIALIZED))
+    initialize(mdp);
 
-  if (size < sizeof (struct list)) {
-    size = sizeof (struct list);
-  }
+  mmalloc_paranoia(mdp);
 
   /* Determine the allocation policy based on the request size.  */
-  if (size <= BLOCKSIZE / 2)
-  {
+  if (size <= BLOCKSIZE / 2) {
     /* Small allocation to receive a fragment of a block.
-	 Determine the logarithm to base two of the fragment size. */
+       Determine the logarithm to base two of the fragment size. */
     log = 1;
     --size;
-    while ((size /= 2) != 0)
-    {
+    while ((size /= 2) != 0) {
       ++log;
     }
 
-    /* Look in the fragment lists for a
-	 free fragment of the desired size. */
-    next = mdp -> fraghead[log].next;
-    if (next != NULL)
-    {
-      /* There are free fragments of this size.
-	     Pop a fragment out of the fragment list and return it.
-	     Update the block's nfree and first counters. */
-      result = (void*) next;
-      next -> prev -> next = next -> next;
-      if (next -> next != NULL)
-      {
-        next -> next -> prev = next -> prev;
-      }
-      block = BLOCK (result);
-      if (--mdp -> heapinfo[block].busy.info.frag.nfree != 0)
-      {
-        mdp -> heapinfo[block].busy.info.frag.first =
-            RESIDUAL (next -> next, BLOCKSIZE) >> log;
+    /* Look in the fragment lists for a free fragment of the desired size. */
+    if (xbt_swag_size(&mdp->fraghead[log])>0) {
+      /* There are free fragments of this size; Get one of them and prepare to return it.
+         Update the block's nfree and if no other free fragment, get out of the swag. */
+
+      /* search a fragment that I could return as a result */
+      malloc_info *candidate_info = xbt_swag_getFirst(&mdp->fraghead[log]);
+      size_t candidate_block = (candidate_info - &(mdp->heapinfo[0]));
+      size_t candidate_frag;
+      for (candidate_frag=0;candidate_frag<(size_t) (BLOCKSIZE >> log);candidate_frag++)
+        if (candidate_info->busy_frag.frag_size[candidate_frag] == -1)
+          break;
+      xbt_assert(candidate_frag < (size_t) (BLOCKSIZE >> log),
+          "Block %zu was registered as containing free fragments of type %zu, but I can't find any",candidate_block,log);
+
+      result = (void*) (((char*)ADDRESS(candidate_block)) + (candidate_frag << log));
+
+      /* Remove this fragment from the list of free guys */
+      candidate_info->busy_frag.nfree--;
+      if (candidate_info->busy_frag.nfree == 0) {
+        xbt_swag_remove(candidate_info,&mdp->fraghead[log]);
       }
 
+      /* Update our metadata about this fragment */
+      candidate_info->busy_frag.frag_size[candidate_frag] = requested_size;
+      xbt_backtrace_no_malloc(candidate_info->busy_frag.bt[candidate_frag],XBT_BACKTRACE_SIZE);
+
       /* Update the statistics.  */
       mdp -> heapstats.chunks_used++;
       mdp -> heapstats.bytes_used += 1 << log;
       mdp -> heapstats.chunks_free--;
       mdp -> heapstats.bytes_free -= 1 << log;
-    }
-    else
-    {
+
+    } else {
       /* No free fragments of the desired size, so get a new block
-	     and break it into fragments, returning the first.  */
-      UNLOCK(mdp);
-      printf("(%s) No free fragment...",xbt_thread_self_name());
-      result = mmalloc (md, BLOCKSIZE);
-      printf("(%s) Fragment: %p...",xbt_thread_self_name(),result);
-      LOCK(mdp);
-      if (result == NULL)
-      {
-        UNLOCK(mdp);
-        return (NULL);
-      }
+         and break it into fragments, returning the first.  */
 
-      /* Link all fragments but the first into the free list.  */
-      for (i = 1; i < (size_t) (BLOCKSIZE >> log); ++i)
-      {
-        next = (struct list *) ((char*) result + (i << log));
-        next -> next = mdp -> fraghead[log].next;
-        next -> prev = &mdp -> fraghead[log];
-        next -> prev -> next = next;
-        if (next -> next != NULL)
-        {
-          next -> next -> prev = next;
-        }
+      result = mmalloc(mdp, BLOCKSIZE); // does not return NULL
+      block = BLOCK(result);
+
+      mdp->heapinfo[block].type = log;
+      /* Link all fragments but the first as free, and add the block to the swag of blocks containing free frags  */
+      for (i = 1; i < (size_t) (BLOCKSIZE >> log); ++i) {
+        mdp->heapinfo[block].busy_frag.frag_size[i] = -1;
       }
+      mdp->heapinfo[block].busy_frag.nfree = i - 1;
+      mdp->heapinfo[block].freehook.prev = NULL;
+      mdp->heapinfo[block].freehook.next = NULL;
 
-      /* Initialize the nfree and first counters for this block.  */
-      block = BLOCK (result);
-      mdp -> heapinfo[block].busy.type = log;
-      mdp -> heapinfo[block].busy.info.frag.nfree = i - 1;
-      mdp -> heapinfo[block].busy.info.frag.first = i - 1;
+      xbt_swag_insert(&mdp->heapinfo[block], &(mdp->fraghead[log]));
 
+      /* mark the fragment returned as busy */
+      mdp->heapinfo[block].busy_frag.frag_size[0] = requested_size;
+      xbt_backtrace_no_malloc(mdp->heapinfo[block].busy_frag.bt[0],XBT_BACKTRACE_SIZE);
+      
+      /* update stats */
       mdp -> heapstats.chunks_free += (BLOCKSIZE >> log) - 1;
       mdp -> heapstats.bytes_free += BLOCKSIZE - (1 << log);
       mdp -> heapstats.bytes_used -= BLOCKSIZE - (1 << log);
     }
-  }
-  else
-  {
+  } else {
     /* Large allocation to receive one or more blocks.
-	 Search the free list in a circle starting at the last place visited.
-	 If we loop completely around without finding a large enough
-	 space we will have to get more memory from the system.  */
+       Search the free list in a circle starting at the last place visited.
+       If we loop completely around without finding a large enough
+       space we will have to get more memory from the system.  */
     blocks = BLOCKIFY(size);
     start = block = MALLOC_SEARCH_START;
-    while (mdp -> heapinfo[block].free.size < blocks)
-    {
-      block = mdp -> heapinfo[block].free.next;
-      if (block == start)
-      {
+    while (mdp->heapinfo[block].free_block.size < blocks) {
+      if (mdp->heapinfo[block].type >=0) { // Don't trust xbt_die and friends in malloc-level library, you fool!
+        fprintf(stderr,"Internal error: found a free block not marked as such (block=%lu type=%lu). Please report this bug.\n",(unsigned long)block,(unsigned long)mdp->heapinfo[block].type);
+        abort();
+      }
+
+      block = mdp->heapinfo[block].free_block.next;
+      if (block == start) {
         /* Need to get more from the system.  Check to see if
-		 the new core will be contiguous with the final free
-		 block; if so we don't need to get as much.  */
-        block = mdp -> heapinfo[0].free.prev;
-        lastblocks = mdp -> heapinfo[block].free.size;
-        if (mdp -> heaplimit != 0 &&
-            block + lastblocks == mdp -> heaplimit &&
-            mdp -> morecore (mdp, 0) == ADDRESS(block + lastblocks) &&
-            (morecore (mdp, (blocks - lastblocks) * BLOCKSIZE)) != NULL)
-        {
+           the new core will be contiguous with the final free
+           block; if so we don't need to get as much.  */
+        block = mdp->heapinfo[0].free_block.prev;
+        lastblocks = mdp->heapinfo[block].free_block.size;
+        if (mdp->heaplimit != 0 &&
+            block + lastblocks == mdp->heaplimit &&
+            mmorecore(mdp, 0) == ADDRESS(block + lastblocks) &&
+            (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;
+             block' referred to above) might have changed, if
+             it got combined with a freed info table.  */
+          block = mdp->heapinfo[0].free_block.prev;
 
-          mdp -> heapinfo[block].free.size += (blocks - lastblocks);
-          mdp -> heapstats.bytes_free +=
-              (blocks - lastblocks) * BLOCKSIZE;
+          mdp->heapinfo[block].free_block.size += (blocks - lastblocks);
           continue;
         }
-        result = morecore(mdp, blocks * BLOCKSIZE);
-        if (result == NULL)
-        {
-          UNLOCK(mdp);
-          return (NULL);
+        result = register_morecore(mdp, blocks * BLOCKSIZE);
+
+        block = BLOCK(result);
+        for (it=0;it<blocks;it++){
+          mdp->heapinfo[block+it].type = 0;
         }
-        block = BLOCK (result);
-        mdp -> heapinfo[block].busy.type = 0;
-        mdp -> heapinfo[block].busy.info.size = blocks;
+        mdp->heapinfo[block].busy_block.size = blocks;
+        mdp->heapinfo[block].busy_block.busy_size = requested_size;
+        mdp->heapinfo[block].busy_block.bt_size=xbt_backtrace_no_malloc(mdp->heapinfo[block].busy_block.bt,XBT_BACKTRACE_SIZE);
         mdp -> heapstats.chunks_used++;
         mdp -> heapstats.bytes_used += blocks * BLOCKSIZE;
-        UNLOCK(mdp);
-        return (result);
+
+        return result;
       }
+      /* Need large block(s), but found some in the existing heap */
     }
 
     /* At this point we have found a suitable free list entry.
-	 Figure out how to remove what we need from the list. */
+       Figure out how to remove what we need from the list. */
     result = ADDRESS(block);
-    if (mdp -> heapinfo[block].free.size > blocks)
-    {
+    if (mdp->heapinfo[block].free_block.size > blocks) {
       /* The block we found has a bit left over,
-	     so relink the tail end back into the free list. */
-      mdp -> heapinfo[block + blocks].free.size
-      = mdp -> heapinfo[block].free.size - blocks;
-      mdp -> heapinfo[block + blocks].free.next
-      = mdp -> heapinfo[block].free.next;
-      mdp -> heapinfo[block + blocks].free.prev
-      = mdp -> heapinfo[block].free.prev;
-      mdp -> heapinfo[mdp -> heapinfo[block].free.prev].free.next
-      = mdp -> heapinfo[mdp -> heapinfo[block].free.next].free.prev
-      = mdp -> heapindex = block + blocks;
-    }
-    else
-    {
+         so relink the tail end back into the free list. */
+      mdp->heapinfo[block + blocks].free_block.size
+        = mdp->heapinfo[block].free_block.size - blocks;
+      mdp->heapinfo[block + blocks].free_block.next
+        = mdp->heapinfo[block].free_block.next;
+      mdp->heapinfo[block + blocks].free_block.prev
+        = mdp->heapinfo[block].free_block.prev;
+      mdp->heapinfo[mdp->heapinfo[block].free_block.prev].free_block.next
+        = mdp->heapinfo[mdp->heapinfo[block].free_block.next].free_block.prev
+        = mdp->heapindex = block + blocks;
+    } else {
       /* The block exactly matches our requirements,
-	     so just remove it from the list. */
-      mdp -> heapinfo[mdp -> heapinfo[block].free.next].free.prev
-      = 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--;
+         so just remove it from the list. */
+      mdp->heapinfo[mdp->heapinfo[block].free_block.next].free_block.prev
+        = mdp->heapinfo[block].free_block.prev;
+      mdp->heapinfo[mdp->heapinfo[block].free_block.prev].free_block.next
+        = mdp->heapindex = mdp->heapinfo[block].free_block.next;
     }
 
-    mdp -> heapinfo[block].busy.type = 0;
-    mdp -> heapinfo[block].busy.info.size = blocks;
+    for (it=0;it<blocks;it++){
+      mdp->heapinfo[block+it].type = 0;
+    }
+    mdp->heapinfo[block].busy_block.size = blocks;
+    mdp->heapinfo[block].busy_block.busy_size = requested_size;
+    //mdp->heapinfo[block].busy_block.bt_size = 0;
+    mdp->heapinfo[block].busy_block.bt_size = xbt_backtrace_no_malloc(mdp->heapinfo[block].busy_block.bt,XBT_BACKTRACE_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);
-  UNLOCK(mdp);
+  //printf("(%s) Done mallocing. Result is %p\n",xbt_thread_self_name(),result);fflush(stdout);
+
   return (result);
 }