1 files changed, 89 insertions, 0 deletions
diff --git a/libs/fluidsynth/src/fluid_ringbuffer.c b/libs/fluidsynth/src/fluid_ringbuffer.c
new file mode 100644
index 0000000000..f6c06dd76d
--- /dev/null
+++ b/libs/fluidsynth/src/fluid_ringbuffer.c
@@ -0,0 +1,89 @@
+/* FluidSynth - A Software Synthesizer
+ *
+ * Copyright (C) 2003  Peter Hanappe and others.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public License
+ * as published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the Free
+ * Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA
+ */
+
+/*
+ * Josh Green <josh@resonance.org>
+ * 2009-05-28
+ */
+
+#include "fluid_ringbuffer.h"
+#include "fluidsynth_priv.h"
+
+
+/**
+ * Create a lock free queue with a fixed maximum count and size of elements.
+ * @param count Count of elements in queue (fixed max number of queued elements)
+ * @return New lock free queue or NULL if out of memory (error message logged)
+ *
+ * Lockless FIFO queues don't use any locking mechanisms and can therefore be
+ * advantageous in certain situations, such as passing data between a lower
+ * priority thread and a higher "real time" thread, without potential lock
+ * contention which could stall the high priority thread.  Note that there may
+ * only be one producer thread and one consumer thread.
+ */
+fluid_ringbuffer_t *
+new_fluid_ringbuffer (int count, int elementsize)
+{
+  fluid_ringbuffer_t *queue;
+
+  fluid_return_val_if_fail (count > 0, NULL);
+
+  queue = FLUID_NEW (fluid_ringbuffer_t);
+
+  if (!queue)
+  {
+    FLUID_LOG (FLUID_ERR, "Out of memory");
+    return NULL;
+  }
+
+  queue->array = FLUID_MALLOC (elementsize * count);
+
+  if (!queue->array)
+  {
+    FLUID_FREE (queue);
+    FLUID_LOG (FLUID_ERR, "Out of memory");
+    return NULL;
+  }
+
+  /* Clear array, in case dynamic pointer reclaiming is being done */
+  FLUID_MEMSET (queue->array, 0, elementsize * count);
+
+  queue->totalcount = count;
+  queue->elementsize = elementsize;
+  queue->count = 0;
+  queue->in = 0;
+  queue->out = 0;
+
+  return (queue);
+}
+
+/**
+ * Free an event queue.
+ * @param queue Lockless queue instance
+ *
+ * Care must be taken when freeing a queue, to ensure that the consumer and
+ * producer threads will no longer access it.
+ */
+void
+delete_fluid_ringbuffer (fluid_ringbuffer_t *queue)
+{
+  FLUID_FREE (queue->array);
+  FLUID_FREE (queue);
+}