上面就是内存池的创建函数，入参共有五个参数，分别是mempool结构、名称、block大小、pool起始地址、pool大小。函数基本内容如下所示，
（1）判断内存池、指针参数合法性；
（2）检验指针是否n字节对齐，n取决于地址的大小；
（3）构建block链表，前后相连，最后一个block指向NULL指针；
（4）将pool首地址赋值给raw_block_pool_available_list，函数返回。
| RAW_U16 raw_block_allocate(MEM_POOL *pool_ptr, RAW_VOID **block_ptr, RAW_U32 wait_option) { RAW_U16 status; RAW_U8 *work_ptr; RAW_SR_ALLOC(); #if (RAW_BLOCK_FUNCTION_CHECK > 0) if (pool_ptr == 0) { return RAW_NULL_OBJECT; } if (block_ptr == 0) { return RAW_NULL_POINTER; } if (raw_int_nesting) { if (wait_option != RAW_NO_WAIT) { return RAW_NOT_CALLED_BY_ISR; } } #endif RAW_CRITICAL_ENTER(); /* Determine if there is an available block. */ if (pool_ptr ->raw_block_pool_available) { /* Yes, a block is available. Decrement the available count. */ pool_ptr ->raw_block_pool_available--; /* Pickup the current block pointer. */ work_ptr = pool_ptr ->raw_block_pool_available_list; /* Return the first available block to the caller. */ *((RAW_U8 **)block_ptr) = work_ptr; /* Modify the available list to point at the next block in the pool. */ pool_ptr ->raw_block_pool_available_list = *((RAW_U8 **)work_ptr); /* Set status to success. */ status = RAW_SUCCESS; } /*if no block memory is available then do it depend wait_option*/ else { if (wait_option == RAW_NO_WAIT) { *((RAW_U8 **)block_ptr) = 0; RAW_CRITICAL_EXIT(); return RAW_NO_PEND_WAIT; } /*system is locked so task can not be blocked just return immediately*/ if (raw_sched_lock) { *((RAW_U8 **)block_ptr) = 0; RAW_CRITICAL_EXIT(); return RAW_SCHED_DISABLE; } raw_pend_object(&pool_ptr->common_block_obj, raw_task_active, wait_option); RAW_CRITICAL_EXIT(); raw_sched(); RAW_CRITICAL_ENTER(); *((RAW_U8 **)block_ptr) = 0; status = block_state_post_process(raw_task_active, block_ptr); RAW_CRITICAL_EXIT(); } return status; } |
