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Diffstat (limited to 'os/rt/src/chmempools.c')
| -rw-r--r-- | os/rt/src/chmempools.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/os/rt/src/chmempools.c b/os/rt/src/chmempools.c new file mode 100644 index 000000000..d92ea7517 --- /dev/null +++ b/os/rt/src/chmempools.c @@ -0,0 +1,194 @@ +/*
+ ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
+ 2011,2012,2013 Giovanni Di Sirio.
+
+ This file is part of ChibiOS/RT.
+
+ ChibiOS/RT is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ ChibiOS/RT is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/**
+ * @file chmempools.c
+ * @brief Memory Pools code.
+ *
+ * @addtogroup pools
+ * @details Memory Pools related APIs and services.
+ * <h2>Operation mode</h2>
+ * The Memory Pools APIs allow to allocate/free fixed size objects in
+ * <b>constant time</b> and reliably without memory fragmentation
+ * problems.<br>
+ * Memory Pools do not enforce any alignment constraint on the
+ * contained object however the objects must be properly aligned
+ * to contain a pointer to void.
+ * @pre In order to use the memory pools APIs the @p CH_CFG_USE_MEMPOOLS option
+ * must be enabled in @p chconf.h.
+ * @{
+ */
+
+#include "ch.h"
+
+#if CH_CFG_USE_MEMPOOLS || defined(__DOXYGEN__)
+
+/*===========================================================================*/
+/* Module exported variables. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module local types. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module local variables. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module local functions. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module exported functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Initializes an empty memory pool.
+ *
+ * @param[out] mp pointer to a @p memory_pool_t structure
+ * @param[in] size the size of the objects contained in this memory pool,
+ * the minimum accepted size is the size of a pointer to
+ * void.
+ * @param[in] provider memory provider function for the memory pool or
+ * @p NULL if the pool is not allowed to grow
+ * automatically
+ *
+ * @init
+ */
+void chPoolObjectInit(memory_pool_t *mp, size_t size, memgetfunc_t provider) {
+
+ chDbgCheck((mp != NULL) && (size >= sizeof(void *)));
+
+ mp->mp_next = NULL;
+ mp->mp_object_size = size;
+ mp->mp_provider = provider;
+}
+
+/**
+ * @brief Loads a memory pool with an array of static objects.
+ * @pre The memory pool must be already been initialized.
+ * @pre The array elements must be of the right size for the specified
+ * memory pool.
+ * @post The memory pool contains the elements of the input array.
+ *
+ * @param[in] mp pointer to a @p memory_pool_t structure
+ * @param[in] p pointer to the array first element
+ * @param[in] n number of elements in the array
+ *
+ * @api
+ */
+void chPoolLoadArray(memory_pool_t *mp, void *p, size_t n) {
+
+ chDbgCheck((mp != NULL) && (n != 0));
+
+ while (n) {
+ chPoolAdd(mp, p);
+ p = (void *)(((uint8_t *)p) + mp->mp_object_size);
+ n--;
+ }
+}
+
+/**
+ * @brief Allocates an object from a memory pool.
+ * @pre The memory pool must be already been initialized.
+ *
+ * @param[in] mp pointer to a @p memory_pool_t structure
+ * @return The pointer to the allocated object.
+ * @retval NULL if pool is empty.
+ *
+ * @iclass
+ */
+void *chPoolAllocI(memory_pool_t *mp) {
+ void *objp;
+
+ chDbgCheckClassI();
+ chDbgCheck(mp != NULL);
+
+ if ((objp = mp->mp_next) != NULL)
+ mp->mp_next = mp->mp_next->ph_next;
+ else if (mp->mp_provider != NULL)
+ objp = mp->mp_provider(mp->mp_object_size);
+ return objp;
+}
+
+/**
+ * @brief Allocates an object from a memory pool.
+ * @pre The memory pool must be already been initialized.
+ *
+ * @param[in] mp pointer to a @p memory_pool_t structure
+ * @return The pointer to the allocated object.
+ * @retval NULL if pool is empty.
+ *
+ * @api
+ */
+void *chPoolAlloc(memory_pool_t *mp) {
+ void *objp;
+
+ chSysLock();
+ objp = chPoolAllocI(mp);
+ chSysUnlock();
+ return objp;
+}
+
+/**
+ * @brief Releases an object into a memory pool.
+ * @pre The memory pool must be already been initialized.
+ * @pre The freed object must be of the right size for the specified
+ * memory pool.
+ * @pre The object must be properly aligned to contain a pointer to void.
+ *
+ * @param[in] mp pointer to a @p memory_pool_t structure
+ * @param[in] objp the pointer to the object to be released
+ *
+ * @iclass
+ */
+void chPoolFreeI(memory_pool_t *mp, void *objp) {
+ struct pool_header *php = objp;
+
+ chDbgCheckClassI();
+ chDbgCheck((mp != NULL) && (objp != NULL));
+
+ php->ph_next = mp->mp_next;
+ mp->mp_next = php;
+}
+
+/**
+ * @brief Releases an object into a memory pool.
+ * @pre The memory pool must be already been initialized.
+ * @pre The freed object must be of the right size for the specified
+ * memory pool.
+ * @pre The object must be properly aligned to contain a pointer to void.
+ *
+ * @param[in] mp pointer to a @p memory_pool_t structure
+ * @param[in] objp the pointer to the object to be released
+ *
+ * @api
+ */
+void chPoolFree(memory_pool_t *mp, void *objp) {
+
+ chSysLock();
+ chPoolFreeI(mp, objp);
+ chSysUnlock();
+}
+
+#endif /* CH_CFG_USE_MEMPOOLS */
+
+/** @} */
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