/*
 * Copyright (C) 2012 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 _FAST_FORWARD_COMMON_H_
#define _FAST_FORWARD_COMMON_H_ 1

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

#ifndef SHARED_SPACE_SIZE
#define SHARED_SPACE_SIZE (16 * BUF_SIZE)
#endif
#define SHARED_SPACE_VOIDPTR (SHARED_SPACE_SIZE / sizeof(void *))

#ifndef BUF_SIZE
#define BUF_SIZE CACHE_LINE_SIZE
#endif

#define DANGER (2 * BUF_SIZE / sizeof(void *))
#define GOOD (6 * BUF_SIZE / sizeof(void *))
#define ADJUST_FREQ 64

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

__BEGIN_DECLS

extern int adjust_slip(struct channel *channel);

static inline void send(struct channel *channel, void **addr)
{
	static __thread unsigned int nb_iter = 0;

	assert(addr != NULL);
	if (nb_iter == ADJUST_FREQ)
	{
		adjust_slip(channel);
		nb_iter = 0;
	}
	while (1)
	{
		if (channel->shared_space[channel->head] != NULL)
			continue;
		channel->shared_space[channel->head] = addr;
		channel->head = (channel->head + 1) % SHARED_SPACE_VOIDPTR;
		break;
	}
}

__END_DECLS

#endif