X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/6ee7e9c2e455536ab817ae0136acfbb53822eecd..14608bd75984c1dc3e279f67ccce7a3accb7650a:/src/xbt/mallocator.c

diff --git a/src/xbt/mallocator.c b/src/xbt/mallocator.c
index 1111a344c1..d3a7236e01 100644
--- a/src/xbt/mallocator.c
+++ b/src/xbt/mallocator.c
@@ -1,6 +1,6 @@
 /* mallocator - recycle objects to avoid malloc() / free()                  */
 
-/* Copyright (c) 2006, 2007, 2008, 2009, 2010. The SimGrid Team.
+/* Copyright (c) 2006-2011. The SimGrid Team.
  * All rights reserved.                                                     */
 
 /* This program is free software; you can redistribute it and/or modify it
@@ -14,6 +14,53 @@
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_mallocator, xbt, "Mallocators");
 
+/** Implementation note on the mallocators:
+ *
+ * Mallocators and memory mess introduced by model-checking do not mix well
+ * together: the mallocator will give standard memory when we are using raw
+ * memory (so these blocks are killed on restore) and the contrary (so these
+ * blocks will leak across restores).
+ *
+ * In addition, model-checking is activated when the command-line arguments
+ * are parsed, at the beginning of main, while most of the mallocators are
+ * created during the constructor functions launched from xbt_preinit, before
+ * the beginning of the main function.
+ *
+ * We want the code as fast as possible when they are active while we can deal
+ * with a little slow-down when they are inactive. So we start the mallocators
+ * as inactive. When they are so, they check at each use whether they should
+ * switch to the fast active mode or should stay in inactive mode.
+ * Finally, we give external elements a way to switch them
+ * all to the active mode (through xbt_mallocator_initialization_is_done).
+ *
+ * This design avoids to store all mallocators somewhere for later conversion,
+ * which would be hard to achieve provided that all our data structures use
+ * some mallocators internally...
+ */
+
+
+static int initialization_done = 0;
+/**
+ * This function must be called once the framework configuration is done. If not,
+ * mallocators will never get used. Check the implementation notes in
+ * src/xbt/mallocator.c for the justification of this.
+ *
+ * For example, surf_config uses this function to tell to the mallocators that
+ * the simgrid
+ * configuration is now finished and that it can create them if not done yet */
+void xbt_mallocator_initialization_is_done(void) {
+  initialization_done = 1;
+}
+
+/** used by the module to know if it's time to activate the mallocators yet */
+static XBT_INLINE int xbt_mallocator_is_active(void) {
+#if MALLOCATOR_COMPILED_IN
+  return initialization_done && !MC_is_active();
+#else
+  return 0;
+#endif
+}
+
 /**
  * \brief Constructor
  * \param size size of the internal stack: number of objects the mallocator
@@ -24,7 +71,7 @@ XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_mallocator, xbt, "Mallocators");
  * in \a xbt_mallocator_release() when the stack is full, and when
  * the mallocator is freed.
  * \param reset_f function to reinitialise an object of your datatype, called
- * when you extract an object from the mallocator
+ * when you extract an object from the mallocator (can be NULL)
  *
  * Create and initialize a new mallocator for a given datatype.
  *
@@ -36,34 +83,19 @@ xbt_mallocator_t xbt_mallocator_new(int size,
                                     void_f_pvoid_t free_f,
                                     void_f_pvoid_t reset_f)
 {
-
-
   xbt_mallocator_t m;
 
-  xbt_assert0(size > 0, "size must be positive");
-  xbt_assert0(new_f != NULL && free_f != NULL
-              && reset_f != NULL, "invalid parameter");
-
-  /* Let's force 0 size mallocator! (Dirty hack, blame Martin :) ) */
-
-  /* mallocators and memory mess introduced by model-checking do not mix well together:
-   *   The mallocator will give standard memory when we are using raw memory (so these blocks are killed on restore)
-   *   and the contrary (so these blocks will leak accross restores)
-   */
-  if (MC_IS_ENABLED)
-    size = 0;
+  xbt_assert(size > 0, "size must be positive");
+  xbt_assert(new_f != NULL && free_f != NULL, "invalid parameter");
 
   m = xbt_new0(s_xbt_mallocator_t, 1);
-  XBT_VERB("Create mallocator %p", m);
-  if (XBT_LOG_ISENABLED(xbt_mallocator, xbt_log_priority_verbose))
-    xbt_backtrace_display_current();
-
-  m->objects = xbt_new0(void *, MC_IS_ENABLED ? 1 : size);
-  m->max_size = size;
+  XBT_VERB("Create mallocator %p (%s)",
+           m, xbt_mallocator_is_active() ? "enabled" : "disabled");
   m->current_size = 0;
   m->new_f = new_f;
   m->free_f = free_f;
   m->reset_f = reset_f;
+  m->max_size = size;
 
   return m;
 }
@@ -80,14 +112,15 @@ void xbt_mallocator_free(xbt_mallocator_t m)
 {
 
   int i;
-  xbt_assert0(m != NULL, "Invalid parameter");
+  xbt_assert(m != NULL, "Invalid parameter");
 
   XBT_VERB("Frees mallocator %p (size:%d/%d)", m, m->current_size,
         m->max_size);
   for (i = 0; i < m->current_size; i++) {
-    (*(m->free_f)) (m->objects[i]);
+    m->free_f(m->objects[i]);
   }
   xbt_free(m->objects);
+  xbt_os_mutex_destroy(m->mutex);
   xbt_free(m);
 }
 
@@ -103,7 +136,7 @@ void xbt_mallocator_free(xbt_mallocator_t m)
  * If the mallocator is empty, a new object is created,
  * by calling the function new_f().
  *
- * In both cases, the function reset_f() is called on the object.
+ * In both cases, the function reset_f() (if defined) is called on the object.
  *
  * \see xbt_mallocator_release()
  */
@@ -111,18 +144,39 @@ void *xbt_mallocator_get(xbt_mallocator_t m)
 {
   void *object;
 
-  if (m->current_size > 0) {
-    /* there is at least an available object */
-    /* XBT_DEBUG("Reuse an old object for mallocator %p (size:%d/%d)", m,
-           m->current_size, m->max_size); */
+  if (m->objects != NULL) { // this mallocator is active, stop thinking and go for it!
+    xbt_os_mutex_acquire(m->mutex);
+    if (m->current_size <= 0) {
+      /* No object is ready yet. Create a bunch of them to try to group the
+       * mallocs on the same memory pages (to help the cache lines) */
+
+      /* XBT_DEBUG("Create a new object for mallocator %p (size:%d/%d)", */
+      /*           m, m->current_size, m->max_size); */
+      int i;
+      int amount = MIN(m->max_size / 2, 1000);
+      for (i = 0; i < amount; i++)
+        m->objects[i] = m->new_f();
+      m->current_size = amount;
+    }
+
+    /* there is at least an available object, now */
+    /* XBT_DEBUG("Reuse an old object for mallocator %p (size:%d/%d)", */
+    /*           m, m->current_size, m->max_size); */
     object = m->objects[--m->current_size];
+    xbt_os_mutex_release(m->mutex);
   } else {
-    /* otherwise we must allocate a new object */
-    /* XBT_DEBUG("Create a new object for mallocator %p (size:%d/%d)", m,
-           m->current_size, m->max_size); */
-    object = (*(m->new_f)) ();
+    if (xbt_mallocator_is_active()) {
+      // We have to switch this mallocator from inactive to active (and then get an object)
+      m->objects = xbt_new0(void *, m->max_size);
+      m->mutex = xbt_os_mutex_init();
+      return xbt_mallocator_get(m);
+    } else {
+      object = m->new_f();
+    }
   }
-  (*(m->reset_f)) (object);
+
+  if (m->reset_f)
+    m->reset_f(object);
   return object;
 }
 
@@ -141,16 +195,30 @@ void *xbt_mallocator_get(xbt_mallocator_t m)
  */
 void xbt_mallocator_release(xbt_mallocator_t m, void *object)
 {
-  if (m->current_size < m->max_size) {
-    /* there is enough place to push the object */
-    /* XBT_DEBUG
-        ("Store deleted object in mallocator %p for further use (size:%d/%d)",
+  if (m->objects != NULL) { // Go for it
+    xbt_os_mutex_acquire(m->mutex);
+    if (m->current_size < m->max_size) {
+      /* there is enough place to push the object */
+      /* XBT_DEBUG
+         ("Store deleted object in mallocator %p for further use (size:%d/%d)",
          m, m->current_size, m->max_size); */
-    m->objects[m->current_size++] = object;
+      m->objects[m->current_size++] = object;
+      xbt_os_mutex_release(m->mutex);
+    } else {
+      xbt_os_mutex_release(m->mutex);
+      /* otherwise we don't have a choice, we must free the object */
+      /* XBT_DEBUG("Free deleted object: mallocator %p is full (size:%d/%d)", m,
+         m->current_size, m->max_size); */
+      m->free_f(object);
+    }
   } else {
-    /* otherwise we don't have a choice, we must free the object */
-    /* XBT_DEBUG("Free deleted object: mallocator %p is full (size:%d/%d)", m,
-           m->current_size, m->max_size); */
-    (*(m->free_f)) (object);
+    if (xbt_mallocator_is_active()) {
+      // We have to switch this mallocator from inactive to active (and then store that object)
+      m->objects = xbt_new0(void *, m->max_size);
+      m->mutex = xbt_os_mutex_init();
+      xbt_mallocator_release(m,object);
+    } else {
+      m->free_f(object);
+    }
   }
 }