omsbuff_gotreader.c

linux下的rtp的实例源代码

/* * 
 *  $Id: OMSbuff_gotreader.c 327 2006-03-28 16:14:41Z shawill $
 *  
 *  This file is part of Fenice
 *
 *  Fenice -- Open Media Server
 *
 *  Copyright (C) 2004 by
 *  	
 *	- Giampaolo Mancini	<[e-mail]>
 *	- Francesco Varano	<[e-mail]>
 *	- Marco Penno		<[e-mail]>
 *	- Federico Ridolfo	<[e-mail]>
 *	- Eugenio Menegatti 	<[e-mail]>
 *	- Stefano Cau
 *	- Giuliano Emma
 *	- Stefano Oldrini
 * 
 *  Fenice 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.
 *
 *  Fenice 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 Fenice; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *  
 * */

#include <stdio.h>

#include <sys/mman.h>

#include <fenice/bufferpool.h>

#define RETURN_ERR { \
					OMSbuff_unlock(cons->buffer); \
					return 1; \
				   }
 
/* ! move current read position
 *
 * \return 1 on error, 0 otherwise
 * */
int32 OMSbuff_gotreader(OMSConsumer *cons)
{
	OMSSlot *last_read;
	OMSSlot *next;

	OMSbuff_lock(cons->buffer);
	
	if (OMSbuff_shm_refresh(cons->buffer))
		RETURN_ERR
		
	last_read = OMStoSlot(cons->buffer, cons->last_read_pos);
	next = &cons->buffer->slots[cons->read_pos];
	
	if ( !next->refs || (next->slot_seq < cons->last_seq) ) {
		// added some slots?
		if ( last_read && cons->buffer->slots[last_read->next].refs && (cons->buffer->slots[last_read->next].slot_seq > cons->last_seq) )
			next = &cons->buffer->slots[last_read->next];
		else
			RETURN_ERR
	} else if (last_read && ( cons->buffer->slots[last_read->next].slot_seq < next->slot_seq ) )
			next = &cons->buffer->slots[last_read->next];

	next->refs--;

	cons->last_seq = next->slot_seq;
	
//	if ( msync(next, sizeof(OMSSlot), MS_ASYNC) )
//	if ( msync(cons->buffer->slots, cons->buffer->known_slots * sizeof(OMSSlot), MS_ASYNC) )
//		printf("*** slot msync error\n");

	cons->last_read_pos = OMStoSlotPtr(cons->buffer, next);
	cons->read_pos = next->next;

	// cons->read_pos->refs--;
	OMSbuff_dump(cons, NULL);
	OMSbuff_unlock(cons->buffer);
	
	// return cons->read_pos;
	return 0; // next;
}
#undef RETURN_ERR