chris@160: /**
chris@160:  * Copyright (c) 2014, 2015, Enzien Audio Ltd.
chris@160:  *
chris@160:  * Permission to use, copy, modify, and/or distribute this software for any
chris@160:  * purpose with or without fee is hereby granted, provided that the above
chris@160:  * copyright notice and this permission notice appear in all copies.
chris@160:  *
chris@160:  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
chris@160:  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
chris@160:  * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
chris@160:  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
chris@160:  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
chris@160:  * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
chris@160:  * PERFORMANCE OF THIS SOFTWARE.
chris@160:  */
chris@160: 
chris@160: #include "MessagePool.h"
chris@160: #include "HvMessage.h"
chris@160: #include "Utils.h"
chris@160: 
chris@160: // the number of bytes reserved at a time from the pool
chris@160: #define MP_BLOCK_SIZE_BYTES 512
chris@160: 
chris@160: #if HV_APPLE
chris@160: #pragma mark - MessageList
chris@160: #endif
chris@160: 
chris@160: typedef struct MessageListNode {
chris@160:   char *p;
chris@160:   struct MessageListNode *next;
chris@160: } MessageListNode;
chris@160: 
chris@160: static inline bool ml_hasAvailable(MessagePoolList *ml) {
chris@160:   return (ml->head != NULL);
chris@160: }
chris@160: 
chris@160: static char *ml_pop(MessagePoolList *ml) {
chris@160:   MessageListNode *n = ml->head;
chris@160:   ml->head = n->next;
chris@160:   n->next = ml->pool;
chris@160:   ml->pool = n;
chris@160:   char *const p = n->p;
chris@160:   n->p = NULL; // set to NULL to make it clear that this node does not have a valid buffer
chris@160:   return p;
chris@160: }
chris@160: 
chris@160: /** Push a MessageListNode with the given pointer onto the head of the queue. */
chris@160: static void ml_push(MessagePoolList *ml, void *p) {
chris@160:   MessageListNode *n = NULL;
chris@160:   if (ml->pool != NULL) {
chris@160:     // take an empty MessageListNode from the pool
chris@160:     n = ml->pool;
chris@160:     ml->pool = n->next;
chris@160:   } else {
chris@160:     // a MessageListNode is not available, allocate one
chris@160:     n = (MessageListNode *) hv_malloc(sizeof(MessageListNode));
chris@160:   }
chris@160:   n->p = (char *) p;
chris@160:   n->next = ml->head;
chris@160:   ml->head = n; // push to the front of the queue
chris@160: }
chris@160: 
chris@160: static void ml_free(MessagePoolList *ml) {
chris@160:   if (ml != NULL) {
chris@160:     while (ml_hasAvailable(ml)) {
chris@160:       ml_pop(ml);
chris@160:     }
chris@160:     while (ml->pool != NULL) {
chris@160:       MessageListNode *n = ml->pool;
chris@160:       ml->pool = n->next;
chris@160:       hv_free(n);
chris@160:     }
chris@160:   }
chris@160: }
chris@160: 
chris@160: #if HV_APPLE
chris@160: #pragma mark - MessagePool
chris@160: #endif
chris@160: 
chris@160: static hv_size_t mp_messagelistIndexForSize(hv_size_t byteSize) {
chris@160:   return (hv_size_t) hv_max_i((hv_min_max_log2((hv_uint32_t) byteSize) - 5), 0);
chris@160: }
chris@160: 
chris@160: hv_size_t mp_init(MessagePool *mp, hv_size_t numKB) {
chris@160:   mp->bufferSize = numKB * 1024;
chris@160:   mp->buffer = (char *) hv_malloc(mp->bufferSize);
chris@160:   mp->bufferIndex = 0;
chris@160: 
chris@160:   // initialise all message lists
chris@160:   for (int i = 0; i < MP_NUM_MESSAGE_LISTS; i++) {
chris@160:     mp->lists[i].head = NULL;
chris@160:     mp->lists[i].pool = NULL;
chris@160:   }
chris@160: 
chris@160:   return mp->bufferSize;
chris@160: }
chris@160: 
chris@160: void mp_free(MessagePool *mp) {
chris@160:   hv_free(mp->buffer);
chris@160:   for (int i = 0; i < MP_NUM_MESSAGE_LISTS; i++) {
chris@160:     ml_free(&mp->lists[i]);
chris@160:   }
chris@160: }
chris@160: 
chris@160: void mp_freeMessage(MessagePool *mp, HvMessage *m) {
chris@160:   const hv_size_t b = msg_getNumBytes(m); // the number of bytes that a message occupies in memory
chris@160:   const hv_size_t i = mp_messagelistIndexForSize(b); // the MessagePoolList index in the pool
chris@160:   MessagePoolList *ml = &mp->lists[i];
chris@160:   const hv_size_t chunkSize = 32 << i;
chris@160:   hv_memset(m, chunkSize); // clear the chunk, just in case
chris@160:   ml_push(ml, m);
chris@160: }
chris@160: 
chris@160: HvMessage *mp_addMessage(MessagePool *mp, const HvMessage *m) {
chris@160:   const hv_size_t b = msg_getNumHeapBytes(m);
chris@160:   // determine the message list index to allocate data from based on the msg size
chris@160:   // smallest chunk size is 32 bytes
chris@160:   const hv_size_t i = mp_messagelistIndexForSize(b);
chris@160: 
chris@160:   assert(i < MP_NUM_MESSAGE_LISTS); // how many chunk sizes do we want to support? 32, 64, 128, 256 at the moment
chris@160:   MessagePoolList *ml = &mp->lists[i];
chris@160:   const hv_size_t chunkSize = 32 << i;
chris@160: 
chris@160:   if (ml_hasAvailable(ml)) {
chris@160:     char *buf = ml_pop(ml);
chris@160:     msg_copyToBuffer(m, buf, chunkSize);
chris@160:     return (HvMessage *) buf;
chris@160:   } else {
chris@160:     // if no appropriately sized buffer is immediately available, increase the size of the used buffer
chris@160:     const hv_size_t newIndex = mp->bufferIndex + MP_BLOCK_SIZE_BYTES;
chris@160:     hv_assert(newIndex <= mp->bufferSize); // have we have exceeded the buffer size?
chris@160: 
chris@160:     for (hv_size_t i = mp->bufferIndex; i < newIndex; i += chunkSize) {
chris@160:       ml_push(ml, mp->buffer + i); // push new nodes onto the list with chunk pointers
chris@160:     }
chris@160:     mp->bufferIndex = newIndex;
chris@160:     char *buf = ml_pop(ml);
chris@160:     msg_copyToBuffer(m, buf, chunkSize);
chris@160:     return (HvMessage *) buf;
chris@160:   }
chris@160: }