#ifndef _BATCH_QUEUE_COMMON_COMM_H_
#define _BATCH_QUEUE_COMMON_COMM_H_ 1

#include <stdint.h>
#include <unistd.h>

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

#ifndef BUF_SIZE
#define BUF_SIZE (32 * CACHE_LINE_SIZE)
#endif

struct channel
{
	/* buf must be the first field to allow the buf_mask test */
	void * volatile buf[2][BUF_SIZE / sizeof(void *)] __attribute__ ((aligned (CACHE_LINE_SIZE)));
	struct channel *mapping1; /* accesses to buf[0] and state */
	struct channel *mapping2; /* accesses to buf[1] */
	uintptr_t buf_mask;
	int unused[20] __attribute__ ((aligned (CACHE_LINE_SIZE)));
	volatile unsigned int  state:1 __attribute__ ((aligned (CACHE_LINE_SIZE)));
	void * volatile *sender_ptr __attribute__ ((aligned (CACHE_LINE_SIZE)));
	void * volatile *receiver_ptr __attribute__ ((aligned (CACHE_LINE_SIZE)));
};

void send1(struct channel *channel, void **addr)
	__attribute__ ((visibility ("hidden")));
void send2(struct channel *channel, void **addr)
	__attribute__ ((visibility ("hidden")));

#ifndef _BATCH_QUEUE_C_
#ifndef PAGE_SIZE_HELPER
#define PAGE_SIZE_HELPER 1
void * volatile *_bq_end_buf1;
void * volatile *_bq_end_buf2;
void (*send_ptr)(struct channel *, void **);

void *create_comm_channel_internal(void);
static void *create_comm_channel_helper(void) __attribute__ ((unused));

static void *create_comm_channel_helper(void)
{
	struct channel *channel;

	send_ptr = &send1;
	channel = create_comm_channel_internal();
	_bq_end_buf1 = channel->buf[0] +
		(sizeof channel->buf[0] / sizeof channel->buf[0][0]);
	_bq_end_buf2 = channel->mapping2->buf[1] +
		(sizeof channel->buf[1] / sizeof channel->buf[1][0]);
	return channel;
}

#else
extern uintptr_t _bq_end_buf1;
extern uintptr_t _bq_end_buf2;
extern void (*send_ptr)(struct channel *, void **);
#endif /* PAGE_SIZE_HELPER */

#define create_comm_channel() create_comm_channel_helper()

__BEGIN_DECLS

static inline void send(struct channel *channel, void **addr)
{
	(*send_ptr)(channel, addr);
}

void send1(struct channel *channel, void **addr)
{
	*channel->sender_ptr++ = addr;
	if (unlikely(channel->sender_ptr == _bq_end_buf1))
	{
		while (channel->state);
		channel->state = 1;
		channel->sender_ptr = channel->mapping2->buf[1];
		send_ptr = &send2;
	}
}

void send2(struct channel *channel, void **addr)
{
	*channel->sender_ptr++ = addr;
	if (unlikely(channel->sender_ptr == _bq_end_buf2))
	{
		while (channel->state);
		channel->state = 1;
		channel->sender_ptr = channel->buf[0];
		send_ptr = &send1;
	}
}

__END_DECLS

#endif /* _BATCH_QUEUE_C_ */

#endif