mirror of https://gitee.com/openkylin/linux.git
104 lines
3.0 KiB
C
104 lines
3.0 KiB
C
/*
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* ALSA sequencer Memory Manager
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* Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#ifndef __SND_SEQ_MEMORYMGR_H
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#define __SND_SEQ_MEMORYMGR_H
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#include <sound/seq_kernel.h>
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#include <linux/poll.h>
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/* container for sequencer event (internal use) */
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struct snd_seq_event_cell {
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struct snd_seq_event event;
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struct snd_seq_pool *pool; /* used pool */
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struct snd_seq_event_cell *next; /* next cell */
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};
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/* design note: the pool is a contiguous block of memory, if we dynamicly
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want to add additional cells to the pool be better store this in another
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pool as we need to know the base address of the pool when releasing
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memory. */
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struct snd_seq_pool {
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struct snd_seq_event_cell *ptr; /* pointer to first event chunk */
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struct snd_seq_event_cell *free; /* pointer to the head of the free list */
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int total_elements; /* pool size actually allocated */
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atomic_t counter; /* cells free */
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int size; /* pool size to be allocated */
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int room; /* watermark for sleep/wakeup */
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int closing;
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/* statistics */
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int max_used;
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int event_alloc_nopool;
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int event_alloc_failures;
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int event_alloc_success;
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/* Write locking */
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wait_queue_head_t output_sleep;
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/* Pool lock */
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spinlock_t lock;
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};
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void snd_seq_cell_free(struct snd_seq_event_cell *cell);
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int snd_seq_event_dup(struct snd_seq_pool *pool, struct snd_seq_event *event,
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struct snd_seq_event_cell **cellp, int nonblock, struct file *file);
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/* return number of unused (free) cells */
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static inline int snd_seq_unused_cells(struct snd_seq_pool *pool)
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{
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return pool ? pool->total_elements - atomic_read(&pool->counter) : 0;
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}
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/* return total number of allocated cells */
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static inline int snd_seq_total_cells(struct snd_seq_pool *pool)
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{
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return pool ? pool->total_elements : 0;
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}
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/* init pool - allocate events */
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int snd_seq_pool_init(struct snd_seq_pool *pool);
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/* done pool - free events */
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int snd_seq_pool_done(struct snd_seq_pool *pool);
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/* create pool */
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struct snd_seq_pool *snd_seq_pool_new(int poolsize);
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/* remove pool */
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int snd_seq_pool_delete(struct snd_seq_pool **pool);
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/* init memory */
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int snd_sequencer_memory_init(void);
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/* release event memory */
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void snd_sequencer_memory_done(void);
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/* polling */
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int snd_seq_pool_poll_wait(struct snd_seq_pool *pool, struct file *file, poll_table *wait);
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#endif
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