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/* 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 Lesser General Public License
* as published by the Free Software Foundation; either version 2.1 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser 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 "fluid_sys.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_LOG(FLUID_ERR, "Out of memory");
delete_fluid_ringbuffer(queue);
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;
fluid_atomic_int_set(&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_return_if_fail(queue != NULL);
FLUID_FREE(queue->array);
FLUID_FREE(queue);
}
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