#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>


__thread struct comm *comm;
__thread union ctrl ctrl __attribute__ ((aligned (CACHE_LINE_SIZE)));

int init_library(void)
{
	return 0;
}

int finalize_library(void)
{
	return 0;
}

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

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

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

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

int init_producer_thread(void *comm_param)
{
	comm = (struct comm *) comm_param;
	ctrl.tail = 0;
	return 0;
}

int finalize_producer_thread(void *unused)
{
	comm = NULL;
	ctrl.tail = 0;
	return 0;
}

int init_consumer_thread(void *comm_param)
{
	comm = (struct comm *) comm_param;
	ctrl.head = 0;
	return 0;
}

int finalize_consumer_thread(void *unused)
{
	comm = NULL;
	ctrl.head = 0;
	return 0;
}

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

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

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

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