comparison projects/heavy/circularBuffer/MessagePool.h @ 163:20b52283c7b4 heavy-updated

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

+/**
+ * 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.
+ */
+
+#ifndef _MESSAGE_POOL_H_
+#define _MESSAGE_POOL_H_
+
+#include "Utils.h"
+
+struct HvMessage;
+
+#define MP_NUM_MESSAGE_LISTS 4
+
+typedef struct MessagePoolList {
+  struct MessageListNode *head; // list of currently available blocks
+  struct MessageListNode *pool; // list of currently used blocks
+} MessagePoolList;
+
+typedef struct MessagePool {
+  char *buffer; // the buffer of all messages
+  hv_size_t bufferSize; // in bytes
+  hv_size_t bufferIndex; // the number of total reserved bytes
+
+  MessagePoolList lists[MP_NUM_MESSAGE_LISTS];
+} MessagePool;
+
+/**
+ * The MessagePool is a basic memory management system. It reserves a large block of memory at initialisation
+ * and proceeds to divide this block into smaller chunks (usually 512 bytes) as they are needed. These chunks are
+ * further divided into 32, 64, 128, or 256 sections. Each of these sections is managed by a MessagePoolList (MPL).
+ * An MPL is a linked-list data structure which is initialised such that its own pool of listnodes is filled with nodes
+ * that point at each subblock (e.g. each 32-byte block of a 512-block chunk).
+ *
+ * MessagePool is loosely inspired by TCMalloc. http://goog-perftools.sourceforge.net/doc/tcmalloc.html
+ */
+
+hv_size_t mp_init(struct MessagePool *mp, hv_size_t numKB);
+
+void mp_free(struct MessagePool *mp);
+
+/**
+ * Adds a message to the pool and returns a pointer to the copy. Returns NULL
+ * if no space was available in the pool.
+ */
+struct HvMessage *mp_addMessage(struct MessagePool *mp, const struct HvMessage *m);
+
+void mp_freeMessage(struct MessagePool *mp, struct HvMessage *m);
+
+#endif // _MESSAGE_POOL_H_