rt_benchs/communication_techniques/include/lamport_comm.h

/*
 * Copyright (C) 2010 Thomas Preud'homme <thomas.preud-homme@lip6.fr>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#ifndef _SPECIFIC_COMM_H_
#define _SPECIFIC_COMM_H_ 1

/* Non standard include */
#include <commtech.h>

#ifndef BUF_SIZE
#define BUF_SIZE CACHE_LINE_SIZE
#endif

#define SHARED_SPACE_SIZE (2 * BUF_SIZE)
#define SHARED_SPACE_VOIDPTR (SHARED_SPACE_SIZE / sizeof(void *))

struct channel
{
	void * volatile *shared_space;
	volatile unsigned int cons_idx __attribute__ ((aligned (CACHE_LINE_SIZE)));
	volatile unsigned int prod_idx __attribute__ ((aligned (CACHE_LINE_SIZE)));
};

__BEGIN_DECLS

static inline void send(struct channel *channel, void **addr)
{
	while ((channel->prod_idx + 1) % SHARED_SPACE_VOIDPTR == channel->cons_idx);
	channel->shared_space[channel->prod_idx] = addr;
	channel->prod_idx = (channel->prod_idx + 1) % SHARED_SPACE_VOIDPTR;
}

__END_DECLS

#endif