start on playrtp split

[disorder] / clients / playrtp-mem.c

diff --git a/clients/playrtp-mem.c b/clients/playrtp-mem.c
new file mode 100644 (file)
index 0000000..e101978
--- /dev/null
+++ b/clients/playrtp-mem.c
@@ -0,0 +1,102 @@
+/*
+ * This file is part of DisOrder.
+ * Copyright (C) 2007 Richard Kettlewell
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+ * USA
+ */
+/** @file clients/playrtp-mem.c
+ * @brief RTP player memory management
+ */
+
+#include <config.h>
+#include "types.h"
+
+#include <pthread.h>
+#include <assert.h>
+#include <string.h>
+
+#include "mem.h"
+#include "vector.h"
+#include "heap.h"
+#include "playrtp.h"
+
+/** @brief Linked list of free packets
+ *
+ * This is a linked list of formerly used packets.  For preference we re-use
+ * packets that have already been used rather than unused ones, to limit the
+ * size of the program's working set.  If there are no free packets in the list
+ * we try @ref next_free_packet instead.
+ *
+ * Must hold @ref lock when accessing this.
+ */
+static union free_packet *free_packets;
+
+/** @brief Array of new free packets 
+ *
+ * There are @ref count_free_packets ready to use at this address.  If there
+ * are none left we allocate more memory.
+ *
+ * Must hold @ref lock when accessing this.
+ */
+static union free_packet *next_free_packet;
+
+/** @brief Count of new free packets at @ref next_free_packet
+ *
+ * Must hold @ref lock when accessing this.
+ */
+static size_t count_free_packets;
+
+/** @brief Lock protecting packet allocator */
+static pthread_mutex_t mem_lock = PTHREAD_MUTEX_INITIALIZER;
+
+/** @brief Return a new packet */
+struct packet *new_packet(void) {
+  struct packet *p;
+  
+  pthread_mutex_lock(&mem_lock);
+  if(free_packets) {
+    p = &free_packets->p;
+    free_packets = free_packets->next;
+  } else {
+    if(!count_free_packets) {
+      next_free_packet = xcalloc(1024, sizeof (union free_packet));
+      count_free_packets = 1024;
+    }
+    p = &(next_free_packet++)->p;
+    --count_free_packets;
+  }
+  pthread_mutex_unlock(&mem_lock);
+  return p;
+}
+
+/** @brief Free a packet */
+void free_packet(struct packet *p) {
+  union free_packet *u = (union free_packet *)p;
+  pthread_mutex_lock(&mem_lock);
+  u->next = free_packets;
+  free_packets = u;
+  pthread_mutex_unlock(&mem_lock);
+}
+
+
+/*
+Local Variables:
+c-basic-offset:2
+comment-column:40
+fill-column:79
+indent-tabs-mode:nil
+End:
+*/