1 /* mallocator - recycle objects to avoid malloc() / free() */
3 /* Copyright (c) 2006-2011. The SimGrid Team.
4 * All rights reserved. */
6 /* This program is free software; you can redistribute it and/or modify it
7 * under the terms of the license (GNU LGPL) which comes with this package. */
9 #include "xbt/mallocator.h"
10 #include "xbt/asserts.h"
11 #include "xbt/sysdep.h"
12 #include "mc/mc.h" /* kill mallocators when model-checking is enabled */
13 #include "mallocator_private.h"
15 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_mallocator, xbt, "Mallocators");
17 /* Mallocators and memory mess introduced by model-checking do not mix well
18 * together: the mallocator will give standard memory when we are using raw
19 * memory (so these blocks are killed on restore) and the contrary (so these
20 * blocks will leak accross restores).
22 #define MALLOCATOR_IS_ENABLED (MALLOCATOR_IS_WANTED && !MC_IS_ENABLED)
26 * \param size size of the internal stack: number of objects the mallocator
27 * will be able to store
28 * \param new_f function to allocate a new object of your datatype, called
29 * in \a xbt_mallocator_get() when the mallocator is empty
30 * \param free_f function to free an object of your datatype, called
31 * in \a xbt_mallocator_release() when the stack is full, and when
32 * the mallocator is freed.
33 * \param reset_f function to reinitialise an object of your datatype, called
34 * when you extract an object from the mallocator (can be NULL)
36 * Create and initialize a new mallocator for a given datatype.
38 * \return pointer to the created mallocator
39 * \see xbt_mallocator_free()
41 xbt_mallocator_t xbt_mallocator_new(int size,
43 void_f_pvoid_t free_f,
44 void_f_pvoid_t reset_f)
48 xbt_assert(size > 0, "size must be positive");
49 xbt_assert(new_f != NULL && free_f != NULL, "invalid parameter");
51 m = xbt_new0(s_xbt_mallocator_t, 1);
52 XBT_VERB("Create mallocator %p (%s)",
53 m, MALLOCATOR_IS_ENABLED ? "enabled" : "disabled");
59 if (MALLOCATOR_IS_ENABLED) {
60 m->objects = xbt_new0(void *, size);
62 m->mutex = xbt_os_mutex_init();
72 * \param m the mallocator you want to destroy
74 * Destroy the mallocator and all its data. The function
75 * free_f is called on each object in the mallocator.
77 * \see xbt_mallocator_new()
79 void xbt_mallocator_free(xbt_mallocator_t m)
83 xbt_assert(m != NULL, "Invalid parameter");
85 XBT_VERB("Frees mallocator %p (size:%d/%d)", m, m->current_size,
87 for (i = 0; i < m->current_size; i++) {
88 m->free_f(m->objects[i]);
91 xbt_os_mutex_destroy(m->mutex);
96 * \brief Extract an object from a mallocator
97 * \param m a mallocator
99 * Remove an object from the mallocator and return it.
100 * This function is designed to be used instead of malloc().
101 * If the mallocator is not empty, an object is
102 * extracted from the mallocator and no malloc is done.
104 * If the mallocator is empty, a new object is created,
105 * by calling the function new_f().
107 * In both cases, the function reset_f() (if defined) is called on the object.
109 * \see xbt_mallocator_release()
111 void *xbt_mallocator_get(xbt_mallocator_t m)
115 if (MALLOCATOR_IS_ENABLED) {
116 xbt_os_mutex_acquire(m->mutex);
117 if (m->current_size <= 0) {
118 /* No object is ready yet. Create a bunch of them to try to group the
119 * mallocs on the same memory pages (to help the cache lines) */
121 /* XBT_DEBUG("Create a new object for mallocator %p (size:%d/%d)", */
122 /* m, m->current_size, m->max_size); */
124 int amount = MIN(m->max_size / 2, 1000);
125 for (i = 0; i < amount; i++)
126 m->objects[i] = m->new_f();
127 m->current_size = amount;
130 /* there is at least an available object, now */
131 /* XBT_DEBUG("Reuse an old object for mallocator %p (size:%d/%d)", */
132 /* m, m->current_size, m->max_size); */
133 object = m->objects[--m->current_size];
134 xbt_os_mutex_release(m->mutex);
144 /** \brief Push an object into a mallocator
145 * \param m a mallocator
146 * \param object an object you don't need anymore
148 * Push into the mallocator an object you don't need anymore.
149 * This function is designed to be used instead of free().
150 * If the mallocator is not full, your object if stored into
151 * the mallocator and no free is done.
152 * If the mallocator is full, the object is freed by calling
153 * the function free_f().
155 * \see xbt_mallocator_get()
157 void xbt_mallocator_release(xbt_mallocator_t m, void *object)
159 if (MALLOCATOR_IS_ENABLED) {
160 xbt_os_mutex_acquire(m->mutex);
161 if (m->current_size < m->max_size) {
162 /* there is enough place to push the object */
164 ("Store deleted object in mallocator %p for further use (size:%d/%d)",
165 m, m->current_size, m->max_size); */
166 m->objects[m->current_size++] = object;
167 xbt_os_mutex_release(m->mutex);
169 xbt_os_mutex_release(m->mutex);
170 /* otherwise we don't have a choice, we must free the object */
171 /* XBT_DEBUG("Free deleted object: mallocator %p is full (size:%d/%d)", m,
172 m->current_size, m->max_size); */