91 lines
2.3 KiB
C
91 lines
2.3 KiB
C
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <pthread.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)))
|
|
{
|
|
channel->receiver_idx = 0;
|
|
channel->state = 0;
|
|
channel->sender_idx = 0;
|
|
return channel;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
int destroy_comm_channel(void *channel)
|
|
{
|
|
free(channel);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Copy at max count received data into buf
|
|
* @param buf The buffer in which received data must be copied into
|
|
* @return Number of data received and copied into buf
|
|
*
|
|
* @warning recv_one_data should not be used in conjonction of
|
|
* recv_some_data
|
|
*/
|
|
void *recv_one_data(struct channel *channel)
|
|
{
|
|
void *result;
|
|
|
|
if (unlikely(!(channel->receiver_idx % (BUF_SIZE / sizeof(void *)))))
|
|
while (!channel->state);
|
|
result = channel->buf[channel->receiver_idx++];
|
|
channel->receiver_idx %= (2 * BUF_SIZE) / sizeof(void *);
|
|
if (unlikely(!(channel->receiver_idx % (BUF_SIZE / sizeof(void *)))))
|
|
channel->state = 0;
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* Copy at max count received data into buf
|
|
* @param buf The buffer in which received data must be copied into
|
|
* @return Number of data received and copied into buf
|
|
*
|
|
* @warning recv_some_data should not be used in conjonction of
|
|
* recv_one_data
|
|
* @warning count must be a multiple of BUF_SIZE
|
|
*/
|
|
ssize_t recv_some_data(struct channel *channel, void **buf, size_t count)
|
|
{
|
|
int nb_read;
|
|
|
|
nb_read = 0;
|
|
while (channel->state && nb_read < count)
|
|
{
|
|
int i, n;
|
|
/*
|
|
* cur->receiver_idx point to the last buffer we have read.
|
|
* We go to the next cache line "+ (BUF_SIZE / sizeof(void *))"
|
|
* (because the line is full of void * and then if we are after
|
|
* the second cache line we correct the pointer to point to the
|
|
* first one (this is done by the modulo).
|
|
*/
|
|
i = channel->receiver_idx;
|
|
n = channel->receiver_idx + (BUF_SIZE / sizeof(void *));
|
|
channel->receiver_idx = n % ((2 * BUF_SIZE) / sizeof(void *));
|
|
for(; i < n; i++)
|
|
{
|
|
/*
|
|
* The behaviour of this is not documented but we know
|
|
* the values inside buf won't change during this affectation
|
|
*/
|
|
*buf++ = channel->buf[i];
|
|
}
|
|
nb_read += BUF_SIZE / sizeof(void *);
|
|
channel->state = 0;
|
|
}
|
|
return nb_read;
|
|
}
|