/*
ChibiOS - Copyright (C) 2006..2018 Giovanni Di Sirio.
This file is part of ChibiOS.
ChibiOS 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 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 oslib_mempools
* @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.
* @note Compatible with RT and NIL.
* @{
*/
#include "ch.h"
#if (CH_CFG_USE_MEMPOOLS == TRUE) || 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] align required memory alignment
* @param[in] provider memory provider function for the memory pool or
* @p NULL if the pool is not allowed to grow
* automatically
*
* @init
*/
void chPoolObjectInitAligned(memory_pool_t *mp, size_t size,
unsigned align, memgetfunc_t provider) {
chDbgCheck((mp != NULL) &&
(size >= sizeof(void *)) &&
(align >= PORT_NATURAL_ALIGN) &&
MEM_IS_VALID_ALIGNMENT(align));
mp->next = NULL;
mp->object_size = size;
mp->align = align;
mp->provider = provider;
}
/**
* @brief Loads a memory pool with an array of static objects.
* @pre The memory pool must already be initialized.
* @pre The array elements must be of the right size for the specified
* memory pool.
* @pre The array elements size must be a multiple of the alignment
* requirement for the 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 != 0U));
while (n != 0U) {
chPoolAdd(mp, p);
/*lint -save -e9087 [11.3] Safe cast.*/
p = (void *)(((uint8_t *)p) + mp->object_size);
/*lint -restore*/
n--;
}
}
/**
* @brief Allocates an object from a memory pool.
* @pre The memory pool must already be 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);
objp = mp->next;
/*lint -save -e9013 [15.7] There is no else because it is not needed.*/
if (objp != NULL) {
mp->next = mp->next->next;
}
else if (mp->provider != NULL) {
objp = mp->provider(mp->object_size, mp->align);
chDbgAssert(MEM_IS_ALIGNED(objp, mp->align),
"returned object not aligned");
}
/*lint -restore*/
return objp;
}
/**
* @brief Allocates an object from a memory pool.
* @pre The memory pool must already be 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 already be initialized.
* @pre The freed object must be of the right size for the specified
* memory pool.
* @pre The added object must be properly aligned.
*
* @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) &&
MEM_IS_ALIGNED(objp, mp->align));
php->next = mp->next;
mp->next = php;
}
/**
* @brief Releases an object into a memory pool.
* @pre The memory pool must already be initialized.
* @pre The freed object must be of the right size for the specified
* memory pool.
* @pre The added object must be properly aligned.
*
* @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();
}
#if (CH_CFG_USE_SEMAPHORES == TRUE) || defined(__DOXYGEN__)
/**
* @brief Initializes an empty guarded memory pool.
*
* @param[out] gmp pointer to a @p guarded_memory_pool_t structure
* @param[in] size the size of the objects contained in this guarded
* memory pool, the minimum accepted size is the size
* of a pointer to void.
* @param[in] align required memory alignment
*
* @init
*/
void chGuardedPoolObjectInitAligned(guarded_memory_pool_t *gmp,
size_t size,
unsigned align) {
chPoolObjectInitAligned(&gmp->pool, size, align, NULL);
chSemObjectInit(&gmp->sem, (cnt_t)0);
}
/**
* @brief Loads a guarded memory pool with an array of static objects.
* @pre The guarded memory pool must already be initialized.
* @pre The array elements must be of the right size for the specified
* guarded memory pool.
* @post The guarded memory pool contains the elements of the input array.
*
* @param[in] gmp pointer to a @p guarded_memory_pool_t structure
* @param[in] p pointer to the array first element
* @param[in] n number of elements in the array
*
* @api
*/
void chGuardedPoolLoadArray(guarded_memory_pool_t *gmp, void *p, size_t n) {
chDbgCheck((gmp != NULL) && (n != 0U));
while (n != 0U) {
chGuardedPoolAdd(gmp, p);
/*lint -save -e9087 [11.3] Safe cast.*/
p = (void *)(((uint8_t *)p) + gmp->pool.object_size);
/*lint -restore*/
n--;
}
}
/**
* @brief Allocates an object from a guarded memory pool.
* @pre The guarded memory pool must already be initialized.
*
* @param[in] gmp pointer to a @p guarded_memory_pool_t structure
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_IMMEDIATE immediate timeout.
* - @a TIME_INFINITE no timeout.
* .
* @return The pointer to the allocated object.
* @retval NULL if the operation timed out.
*
* @sclass
*/
void *chGuardedPoolAllocTimeoutS(guarded_memory_pool_t *gmp,
sysinterval_t timeout) {
msg_t msg;
msg = chSemWaitTimeoutS(&gmp->sem, timeout);
if (msg != MSG_OK) {
return NULL;
}
return chPoolAllocI(&gmp->pool);
}
/**
* @brief Allocates an object from a guarded memory pool.
* @pre The guarded memory pool must already be initialized.
*
* @param[in] gmp pointer to a @p guarded_memory_pool_t structure
* @param[in] timeout the number of ticks before the operation timeouts,
* the following special values are allowed:
* - @a TIME_IMMEDIATE immediate timeout.
* - @a TIME_INFINITE no timeout.
* .
* @return The pointer to the allocated object.
* @retval NULL if the operation timed out.
*
* @api
*/
void *chGuardedPoolAllocTimeout(guarded_memory_pool_t *gmp,
sysinterval_t timeout) {
void *p;
chSysLock();
p = chGuardedPoolAllocTimeoutS(gmp, timeout);
chSysUnlock();
return p;
}
/**
* @brief Releases an object into a guarded memory pool.
* @pre The guarded memory pool must already be initialized.
* @pre The freed object must be of the right size for the specified
* guarded memory pool.
* @pre The added object must be properly aligned.
*
* @param[in] gmp pointer to a @p guarded_memory_pool_t structure
* @param[in] objp the pointer to the object to be released
*
* @api
*/
void chGuardedPoolFree(guarded_memory_pool_t *gmp, void *objp) {
chSysLock();
chGuardedPoolFreeI(gmp, objp);
chSchRescheduleS();
chSysUnlock();
}
#endif
#endif /* CH_CFG_USE_MEMPOOLS == TRUE */
/** @} */