#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <unistd.h>

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


void *create_comm_channel(void)
{
	struct channel *channel;

	if (!posix_memalign((void *) &channel, CACHE_LINE_SIZE, sizeof(struct channel)))
	{
		int i;

		for (i = 0; i < SLOTS; i++)
			channel->queue[i].flag = 0;
		channel->head = 0;
		channel->tail = 0;
		return channel;
	}
	return NULL;
}

int destroy_comm_channel(void *channel)
{
	free(channel);
	return 0;
}

void *recv_one_data(struct channel *channel)
{
	static __thread int i;
	void *result;

	if (__builtin_expect(!i, 0))
		while (!channel->queue[channel->head].flag);
	result = channel->queue[channel->head].chunk[i++];
	if (i % SUB_SLOTS)
	{
		i = 0;
		channel->queue[channel->head].flag = 0;
		channel->head = (channel->head + 1) % SLOTS;
	}
	return result;
}

ssize_t recv_some_data(struct channel *channel, void **buf, size_t count)
{
	int n;

	n = 0;
	// If all slots are empty, spin
	while (channel->queue[channel->head].flag)
	{
		// Dequeue a chunk of data items
		memcpy(buf, (const void *)
		       channel->queue[channel->head].chunk,
		       SUB_SLOTS * sizeof(*buf));
		n += SUB_SLOTS;
		channel->queue[channel->head].flag = 0;
		channel->head = (channel->head + 1) % SLOTS;
		if (n == count)
			break;
	}
	return n;
}