91 lines
2.6 KiB
C
91 lines
2.6 KiB
C
/* FluidSynth - A Software Synthesizer
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*
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* Copyright (C) 2003 Peter Hanappe and others.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public License
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* as published by the Free Software Foundation; either version 2.1 of
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* the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free
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* Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA
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*/
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/*
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* Josh Green <josh@resonance.org>
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* 2009-05-28
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*/
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#include "fluid_ringbuffer.h"
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#include "fluid_sys.h"
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/**
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* Create a lock free queue with a fixed maximum count and size of elements.
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* @param count Count of elements in queue (fixed max number of queued elements)
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* @return New lock free queue or NULL if out of memory (error message logged)
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*
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* Lockless FIFO queues don't use any locking mechanisms and can therefore be
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* advantageous in certain situations, such as passing data between a lower
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* priority thread and a higher "real time" thread, without potential lock
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* contention which could stall the high priority thread. Note that there may
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* only be one producer thread and one consumer thread.
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*/
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fluid_ringbuffer_t *
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new_fluid_ringbuffer(int count, int elementsize)
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{
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fluid_ringbuffer_t *queue;
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fluid_return_val_if_fail(count > 0, NULL);
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queue = FLUID_NEW(fluid_ringbuffer_t);
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if(!queue)
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{
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FLUID_LOG(FLUID_ERR, "Out of memory");
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return NULL;
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}
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queue->array = FLUID_MALLOC(elementsize * count);
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if(!queue->array)
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{
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FLUID_LOG(FLUID_ERR, "Out of memory");
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delete_fluid_ringbuffer(queue);
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return NULL;
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}
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/* Clear array, in case dynamic pointer reclaiming is being done */
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FLUID_MEMSET(queue->array, 0, elementsize * count);
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queue->totalcount = count;
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queue->elementsize = elementsize;
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fluid_atomic_int_set(&queue->count, 0);
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queue->in = 0;
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queue->out = 0;
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return (queue);
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}
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/**
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* Free an event queue.
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* @param queue Lockless queue instance
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*
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* Care must be taken when freeing a queue, to ensure that the consumer and
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* producer threads will no longer access it.
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*/
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void
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delete_fluid_ringbuffer(fluid_ringbuffer_t *queue)
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{
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fluid_return_if_fail(queue != NULL);
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FLUID_FREE(queue->array);
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FLUID_FREE(queue);
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}
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