diff projects/heavy/circularBuffer/MessagePool.c @ 163:20b52283c7b4 heavy-updated

- added circular buffer pd/heavy example (works but process needs to be killed manually if launched via ssh?)

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/projects/heavy/circularBuffer/MessagePool.c	Thu Nov 12 15:55:30 2015 +0000
@@ -0,0 +1,141 @@
+/**
+ * Copyright (c) 2014, 2015, Enzien Audio Ltd.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "MessagePool.h"
+#include "HvMessage.h"
+#include "Utils.h"
+
+// the number of bytes reserved at a time from the pool
+#define MP_BLOCK_SIZE_BYTES 512
+
+#if HV_APPLE
+#pragma mark - MessageList
+#endif
+
+typedef struct MessageListNode {
+  char *p;
+  struct MessageListNode *next;
+} MessageListNode;
+
+static inline bool ml_hasAvailable(MessagePoolList *ml) {
+  return (ml->head != NULL);
+}
+
+static char *ml_pop(MessagePoolList *ml) {
+  MessageListNode *n = ml->head;
+  ml->head = n->next;
+  n->next = ml->pool;
+  ml->pool = n;
+  char *const p = n->p;
+  n->p = NULL; // set to NULL to make it clear that this node does not have a valid buffer
+  return p;
+}
+
+/** Push a MessageListNode with the given pointer onto the head of the queue. */
+static void ml_push(MessagePoolList *ml, void *p) {
+  MessageListNode *n = NULL;
+  if (ml->pool != NULL) {
+    // take an empty MessageListNode from the pool
+    n = ml->pool;
+    ml->pool = n->next;
+  } else {
+    // a MessageListNode is not available, allocate one
+    n = (MessageListNode *) hv_malloc(sizeof(MessageListNode));
+  }
+  n->p = (char *) p;
+  n->next = ml->head;
+  ml->head = n; // push to the front of the queue
+}
+
+static void ml_free(MessagePoolList *ml) {
+  if (ml != NULL) {
+    while (ml_hasAvailable(ml)) {
+      ml_pop(ml);
+    }
+    while (ml->pool != NULL) {
+      MessageListNode *n = ml->pool;
+      ml->pool = n->next;
+      hv_free(n);
+    }
+  }
+}
+
+#if HV_APPLE
+#pragma mark - MessagePool
+#endif
+
+static hv_size_t mp_messagelistIndexForSize(hv_size_t byteSize) {
+  return (hv_size_t) hv_max_i((hv_min_max_log2((hv_uint32_t) byteSize) - 5), 0);
+}
+
+hv_size_t mp_init(MessagePool *mp, hv_size_t numKB) {
+  mp->bufferSize = numKB * 1024;
+  mp->buffer = (char *) hv_malloc(mp->bufferSize);
+  mp->bufferIndex = 0;
+
+  // initialise all message lists
+  for (int i = 0; i < MP_NUM_MESSAGE_LISTS; i++) {
+    mp->lists[i].head = NULL;
+    mp->lists[i].pool = NULL;
+  }
+
+  return mp->bufferSize;
+}
+
+void mp_free(MessagePool *mp) {
+  hv_free(mp->buffer);
+  for (int i = 0; i < MP_NUM_MESSAGE_LISTS; i++) {
+    ml_free(&mp->lists[i]);
+  }
+}
+
+void mp_freeMessage(MessagePool *mp, HvMessage *m) {
+  const hv_size_t b = msg_getNumBytes(m); // the number of bytes that a message occupies in memory
+  const hv_size_t i = mp_messagelistIndexForSize(b); // the MessagePoolList index in the pool
+  MessagePoolList *ml = &mp->lists[i];
+  const hv_size_t chunkSize = 32 << i;
+  hv_memset(m, chunkSize); // clear the chunk, just in case
+  ml_push(ml, m);
+}
+
+HvMessage *mp_addMessage(MessagePool *mp, const HvMessage *m) {
+  const hv_size_t b = msg_getNumHeapBytes(m);
+  // determine the message list index to allocate data from based on the msg size
+  // smallest chunk size is 32 bytes
+  const hv_size_t i = mp_messagelistIndexForSize(b);
+
+  assert(i < MP_NUM_MESSAGE_LISTS); // how many chunk sizes do we want to support? 32, 64, 128, 256 at the moment
+  MessagePoolList *ml = &mp->lists[i];
+  const hv_size_t chunkSize = 32 << i;
+
+  if (ml_hasAvailable(ml)) {
+    char *buf = ml_pop(ml);
+    msg_copyToBuffer(m, buf, chunkSize);
+    return (HvMessage *) buf;
+  } else {
+    // if no appropriately sized buffer is immediately available, increase the size of the used buffer
+    const hv_size_t newIndex = mp->bufferIndex + MP_BLOCK_SIZE_BYTES;
+    hv_assert(newIndex <= mp->bufferSize); // have we have exceeded the buffer size?
+
+    for (hv_size_t i = mp->bufferIndex; i < newIndex; i += chunkSize) {
+      ml_push(ml, mp->buffer + i); // push new nodes onto the list with chunk pointers
+    }
+    mp->bufferIndex = newIndex;
+    char *buf = ml_pop(ml);
+    msg_copyToBuffer(m, buf, chunkSize);
+    return (HvMessage *) buf;
+  }
+}