X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/e048b9d6c83f24e8649df8ae09759d4616ec0d30..1a0f69168109c0b38b03b1d1deb9773fdac83e9e:/src/xbt/mallocator.c

diff --git a/src/xbt/mallocator.c b/src/xbt/mallocator.c
index 52d77026d3..ed415a5ed7 100644
--- a/src/xbt/mallocator.c
+++ b/src/xbt/mallocator.c
@@ -1,32 +1,93 @@
+/* mallocator - recycle objects to avoid malloc() / free()                  */
+
+/* Copyright (c) 2006-2011. The SimGrid Team.
+ * All rights reserved.                                                     */
+
+/* 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 "xbt/mallocator.h"
 #include "xbt/asserts.h"
 #include "xbt/sysdep.h"
+#include "mc/mc.h" /* kill mallocators when model-checking is enabled */
 #include "mallocator_private.h"
 
+XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_mallocator, xbt, "Mallocators");
+
+
+/* Change to 0 to completely disable mallocators. */
+#define MALLOCATOR_IS_WANTED 1
+
+/* 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).
+ */
+#define MALLOCATOR_IS_ENABLED (MALLOCATOR_IS_WANTED && !MC_IS_ENABLED)
+
+/**
+ * \brief Constructor
+ * \param size size of the internal stack: number of objects the mallocator
+ * will be able to store
+ * \param new_f function to allocate a new object of your datatype, called
+ * in \a xbt_mallocator_get() when the mallocator is empty
+ * \param free_f function to free an object of your datatype, called
+ * 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 (can be NULL)
+ *
+ * Create and initialize a new mallocator for a given datatype.
+ *
+ * \return pointer to the created mallocator
+ * \see xbt_mallocator_free()
+ */
 xbt_mallocator_t xbt_mallocator_new(int size,
-				    pvoid_f_void_t new_f,
-				    void_f_pvoid_t free_f,
-				    void_f_pvoid_t reset_f) {
-  xbt_assert0(size > 0, "size must be positive");
-  xbt_assert0(new_f != NULL && free_f != NULL && reset_f != NULL,
-	      "invalid parameter");
-  xbt_mallocator_t m = xbt_new0(s_xbt_mallocator_t, 1);
-
-  m->objects = xbt_new0(void*, size);
-  m->max_size = size;
+                                    pvoid_f_void_t new_f,
+                                    void_f_pvoid_t free_f,
+                                    void_f_pvoid_t reset_f)
+{
+  xbt_mallocator_t m;
+
+  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);
   m->current_size = 0;
   m->new_f = new_f;
   m->free_f = free_f;
   m->reset_f = reset_f;
 
+  if (MALLOCATOR_IS_ENABLED) {
+    m->objects = xbt_new0(void *, size);
+    m->max_size = size;
+  } else {
+    if (!MALLOCATOR_IS_WANTED) /* Warn to avoid to commit debugging settings */
+      XBT_WARN("Mallocator is disabled!");
+    m->objects = NULL;
+    m->max_size = 0;
+  }
+
   return m;
 }
 
-/* Destroy the mallocator and all its data */
-void xbt_mallocator_free(xbt_mallocator_t m) {
-  xbt_assert0(m != NULL, "Invalid parameter");
+/** \brief Destructor
+ * \param m the mallocator you want to destroy
+ *
+ * Destroy the mallocator and all its data. The function
+ * free_f is called on each object in the mallocator.
+ *
+ * \see xbt_mallocator_new()
+ */
+void xbt_mallocator_free(xbt_mallocator_t m)
+{
 
   int i;
+  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]);
   }
@@ -34,34 +95,78 @@ void xbt_mallocator_free(xbt_mallocator_t m) {
   xbt_free(m);
 }
 
-/* Return an object (use this function instead of malloc) */
-void *xbt_mallocator_get(xbt_mallocator_t m) {
-  xbt_assert0(m != NULL, "Invalid parameter");
-
+/**
+ * \brief Extract an object from a mallocator
+ * \param m a mallocator
+ *
+ * Remove an object from the mallocator and return it.
+ * This function is designed to be used instead of malloc().
+ * If the mallocator is not empty, an object is
+ * extracted from the mallocator and no malloc is done.
+ *
+ * If the mallocator is empty, a new object is created,
+ * by calling the function new_f().
+ *
+ * In both cases, the function reset_f() (if defined) is called on the object.
+ *
+ * \see xbt_mallocator_release()
+ */
+void *xbt_mallocator_get(xbt_mallocator_t m)
+{
   void *object;
-  if (m->current_size > 0) {
-    /* there is at least an available object */
-    return m->objects[--m->current_size];
-  }
-  else {
-    /* otherwise we must allocate a new object */
+
+  if (MALLOCATOR_IS_ENABLED) {
+    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];
+  } else {
     object = m->new_f();
-    m->reset_f(object);
-    return object;
   }
-}
 
-/* Release an object (use this function instead of free) */
-void xbt_mallocator_release(xbt_mallocator_t m, void *object) {
-  xbt_assert0(m != NULL && object != NULL, "Invalid parameter");
+  if (m->reset_f)
+    m->reset_f(object);
+  return object;
+}
 
+/** \brief Push an object into a mallocator
+ * \param m a mallocator
+ * \param object an object you don't need anymore
+ *
+ * Push into the mallocator an object you don't need anymore.
+ * This function is designed to be used instead of free().
+ * If the mallocator is not full, your object if stored into
+ * the mallocator and no free is done.
+ * If the mallocator is full, the object is freed by calling
+ * the function free_f().
+ *
+ * \see xbt_mallocator_get()
+ */
+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 */
-    m->reset_f(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;
-  }
-  else {
+  } 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);
   }
 }