MemoryPool.h

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2006-2012 ARM Limited
00003  *
00004  * Permission is hereby granted, free of charge, to any person obtaining a copy
00005  * of this software and associated documentation files (the "Software"), to deal
00006  * in the Software without restriction, including without limitation the rights
00007  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00008  * copies of the Software, and to permit persons to whom the Software is
00009  * furnished to do so, subject to the following conditions:
00010  *
00011  * The above copyright notice and this permission notice shall be included in
00012  * all copies or substantial portions of the Software.
00013  *
00014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00017  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00018  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00019  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
00020  * SOFTWARE.
00021  */
00022 #ifndef MEMORYPOOL_H
00023 #define MEMORYPOOL_H
00024 
00025 #include <stdint.h>
00026 #include <string.h>
00027 
00028 #include "cmsis_os2.h"
00029 #include "mbed_rtos1_types.h"
00030 #include "mbed_rtos_storage.h"
00031 #include "platform/NonCopyable.h"
00032 
00033 namespace rtos {
00034 /** \addtogroup rtos */
00035 /** @{*/
00036 /**
00037  * \defgroup rtos_MemoryPool MemoryPool class
00038  * @{
00039  */
00040  
00041 /** Define and manage fixed-size memory pools of objects of a given type.
00042   @tparam  T         data type of a single object (element).
00043   @tparam  queue_sz  maximum number of objects (elements) in the memory pool.
00044 
00045  @note
00046  Memory considerations: The memory pool data store and control structures will be created on current thread's stack,
00047  both for the mbed OS and underlying RTOS objects (static or dynamic RTOS memory pools are not being used).
00048 */
00049 template<typename T, uint32_t pool_sz>
00050 class MemoryPool : private mbed::NonCopyable<MemoryPool<T, pool_sz> > {
00051     MBED_STATIC_ASSERT(pool_sz > 0, "Invalid memory pool size. Must be greater than 0.");
00052 public:
00053     /** Create and Initialize a memory pool.
00054      *
00055      * @note You cannot call this function from ISR context.
00056     */
00057     MemoryPool() {
00058         memset(_pool_mem, 0, sizeof(_pool_mem));
00059         memset(&_obj_mem, 0, sizeof(_obj_mem));
00060         osMemoryPoolAttr_t attr = { 0 };
00061         attr.mp_mem = _pool_mem;
00062         attr.mp_size = sizeof(_pool_mem);
00063         attr.cb_mem = &_obj_mem;
00064         attr.cb_size = sizeof(_obj_mem);
00065         _id = osMemoryPoolNew(pool_sz, sizeof(T), &attr);
00066         MBED_ASSERT(_id);
00067     }
00068 
00069     /** Destroy a memory pool
00070      *
00071      * @note You cannot call this function from ISR context.
00072     */
00073     ~MemoryPool() {
00074         osMemoryPoolDelete(_id);
00075     }
00076 
00077     /** Allocate a memory block of type T from a memory pool.
00078       @return  address of the allocated memory block or NULL in case of no memory available.
00079 
00080       @note You may call this function from ISR context.
00081     */
00082     T* alloc(void) {
00083         return (T*)osMemoryPoolAlloc(_id, 0);
00084     }
00085 
00086     /** Allocate a memory block of type T from a memory pool and set memory block to zero.
00087       @return  address of the allocated memory block or NULL in case of no memory available.
00088 
00089       @note You may call this function from ISR context.
00090     */
00091     T* calloc(void) {
00092         T *item = (T*)osMemoryPoolAlloc(_id, 0);
00093         if (item != NULL) {
00094             memset(item, 0, sizeof(T));
00095         }
00096         return item;
00097     }
00098 
00099     /** Free a memory block.
00100       @param   block  address of the allocated memory block to be freed.
00101       @return         osOK on successful deallocation, osErrorParameter if given memory block id
00102                       is NULL or invalid, or osErrorResource if given memory block is in an
00103                       invalid memory pool state.
00104 
00105       @note You may call this function from ISR context.
00106     */
00107     osStatus free(T *block) {
00108         return osMemoryPoolFree(_id, (void*)block);
00109     }
00110 
00111 private:
00112     osMemoryPoolId_t             _id;
00113     /* osMemoryPoolNew requires that pool block size is a multiple of 4 bytes. */
00114     char                         _pool_mem[((sizeof(T) + 3) & ~3) * pool_sz];
00115     mbed_rtos_storage_mem_pool_t _obj_mem;
00116 };
00117 /** @}*/
00118 /** @}*/
00119 
00120 }
00121 #endif
00122 
00123