chris@162: /**
chris@162:  * Copyright (c) 2014, 2015, Enzien Audio Ltd.
chris@162:  *
chris@162:  * Permission to use, copy, modify, and/or distribute this software for any
chris@162:  * purpose with or without fee is hereby granted, provided that the above
chris@162:  * copyright notice and this permission notice appear in all copies.
chris@162:  *
chris@162:  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
chris@162:  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
chris@162:  * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
chris@162:  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
chris@162:  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
chris@162:  * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
chris@162:  * PERFORMANCE OF THIS SOFTWARE.
chris@162:  */
chris@162: 
chris@162: #ifndef _MESSAGE_POOL_H_
chris@162: #define _MESSAGE_POOL_H_
chris@162: 
chris@162: #include "Utils.h"
chris@162: 
chris@162: struct HvMessage;
chris@162: 
chris@162: #define MP_NUM_MESSAGE_LISTS 4
chris@162: 
chris@162: typedef struct MessagePoolList {
chris@162:   struct MessageListNode *head; // list of currently available blocks
chris@162:   struct MessageListNode *pool; // list of currently used blocks
chris@162: } MessagePoolList;
chris@162: 
chris@162: typedef struct MessagePool {
chris@162:   char *buffer; // the buffer of all messages
chris@162:   hv_size_t bufferSize; // in bytes
chris@162:   hv_size_t bufferIndex; // the number of total reserved bytes
chris@162: 
chris@162:   MessagePoolList lists[MP_NUM_MESSAGE_LISTS];
chris@162: } MessagePool;
chris@162: 
chris@162: /**
chris@162:  * The MessagePool is a basic memory management system. It reserves a large block of memory at initialisation
chris@162:  * and proceeds to divide this block into smaller chunks (usually 512 bytes) as they are needed. These chunks are
chris@162:  * further divided into 32, 64, 128, or 256 sections. Each of these sections is managed by a MessagePoolList (MPL).
chris@162:  * An MPL is a linked-list data structure which is initialised such that its own pool of listnodes is filled with nodes
chris@162:  * that point at each subblock (e.g. each 32-byte block of a 512-block chunk).
chris@162:  *
chris@162:  * MessagePool is loosely inspired by TCMalloc. http://goog-perftools.sourceforge.net/doc/tcmalloc.html
chris@162:  */
chris@162: 
chris@162: hv_size_t mp_init(struct MessagePool *mp, hv_size_t numKB);
chris@162: 
chris@162: void mp_free(struct MessagePool *mp);
chris@162: 
chris@162: /**
chris@162:  * Adds a message to the pool and returns a pointer to the copy. Returns NULL
chris@162:  * if no space was available in the pool.
chris@162:  */
chris@162: struct HvMessage *mp_addMessage(struct MessagePool *mp, const struct HvMessage *m);
chris@162: 
chris@162: void mp_freeMessage(struct MessagePool *mp, struct HvMessage *m);
chris@162: 
chris@162: #endif // _MESSAGE_POOL_H_