From: Martin Quinson <martin.quinson@loria.fr>
Date: Thu, 2 Feb 2012 14:41:34 +0000 (+0100)
Subject: various cosmetics and comments improvements
X-Git-Tag: exp_20120216~85
X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/commitdiff_plain/e56c4673fbfe4965240725a4c09dc294d920c8d5

various cosmetics and comments improvements
---

diff --git a/src/xbt/mmalloc/mm_module.c b/src/xbt/mmalloc/mm_module.c
index 8ec8e73a0d..973c1aeaf1 100644
--- a/src/xbt/mmalloc/mm_module.c
+++ b/src/xbt/mmalloc/mm_module.c
@@ -143,7 +143,8 @@ xbt_mheap_t xbt_mheap_new(int fd, void *baseaddr)
     }
   }
 
-  /* If the user provided NULL BASEADDR then fail */
+  /* NULL is not a valid baseaddr as we cannot map anything there.
+     C'mon, user. Think! */
   if (baseaddr == NULL)
     return (NULL);
 
diff --git a/src/xbt/mmalloc/mmalloc.c b/src/xbt/mmalloc/mmalloc.c
index a5a0192026..23db293271 100644
--- a/src/xbt/mmalloc/mmalloc.c
+++ b/src/xbt/mmalloc/mmalloc.c
@@ -16,18 +16,24 @@
 
 /* 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).
+   */
   adj = RESIDUAL(result, BLOCKSIZE);
   if (adj != 0) {
     adj = BLOCKSIZE - adj;
@@ -37,9 +43,9 @@ 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 +62,9 @@ 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;
@@ -199,7 +204,7 @@ void *mmalloc(xbt_mheap_t mdp, 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.  */
@@ -208,7 +213,7 @@ void *mmalloc(xbt_mheap_t mdp, size_t size)
           mdp->heapinfo[block].free.size += (blocks - lastblocks);
           continue;
         }
-        result = morecore(mdp, blocks * BLOCKSIZE);
+        result = register_morecore(mdp, blocks * BLOCKSIZE);
         if (result == NULL) {
           return (NULL);
         }
diff --git a/src/xbt/mmalloc/mmemalign.c b/src/xbt/mmalloc/mmemalign.c
index 93ca53a2da..cf0cef7d40 100644
--- a/src/xbt/mmalloc/mmemalign.c
+++ b/src/xbt/mmalloc/mmemalign.c
@@ -48,10 +48,9 @@ static size_t cache_pagesize;
 
 void *mvalloc(xbt_mheap_t mdp, size_t size)
 {
-  if (cache_pagesize == 0) {
+  if (cache_pagesize == 0)
     cache_pagesize = getpagesize();
-  }
 
-  return (mmemalign(mdp, cache_pagesize, size));
+  return mmemalign(mdp, cache_pagesize, size);
 }
 
diff --git a/src/xbt/mmalloc/mmprivate.h b/src/xbt/mmalloc/mmprivate.h
index 05cdf9ae6e..41717886b8 100644
--- a/src/xbt/mmalloc/mmprivate.h
+++ b/src/xbt/mmalloc/mmprivate.h
@@ -112,7 +112,6 @@ struct alignlist {
 };
 
 /* Doubly linked lists of free fragments.  */
-
 struct list {
   struct list *next;
   struct list *prev;