libisofs/demo/cat_buffer.c

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/*
* Copyright (c) 2007 Vreixo Formoso
*
* This file is part of the libisofs project; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation. See COPYING file for details.
*/
#include "libisofs.h"
#include "buffer.h"
#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
/*
* Little test program that reads a file and outputs it to stdout, using
* the libisofs ring buffer as intermediate memory
*/
struct th_data {
IsoRingBuffer *rbuf;
char *path;
};
#define WRITE_CHUNK 2048
#define READ_CHUNK 2048
static
void *write_function(void *arg)
{
ssize_t bytes;
int res;
unsigned char tmp[WRITE_CHUNK];
struct th_data *data = (struct th_data *) arg;
int fd = open(data->path, O_RDONLY);
if (fd < 0) {
fprintf(stderr, "Writer thread error: Can't open file");
iso_ring_buffer_writer_close(data->rbuf);
pthread_exit(NULL);
}
res = 1;
while ( (bytes = read(fd, tmp, WRITE_CHUNK)) > 0 ) {
res = iso_ring_buffer_write(data->rbuf, tmp, bytes);
if (res <= 0) {
break;
}
/* To test premature reader exit >>>>>>>>>>>
iso_ring_buffer_writer_close(data->rbuf);
pthread_exit(NULL);
<<<<<<<<<<<<<<<<<<<<<<<<< */
// if (rand() > 2000000000) {
// fprintf(stderr, "Writer sleeping\n");
// sleep(1);
// }
}
fprintf(stderr, "Writer finish: %d\n", res);
close(fd);
iso_ring_buffer_writer_close(data->rbuf);
pthread_exit(NULL);
}
static
void *read_function(void *arg)
{
unsigned char tmp[READ_CHUNK];
int res = 1;
struct th_data *data = (struct th_data *) arg;
while ( (res = iso_ring_buffer_read(data->rbuf, tmp, READ_CHUNK)) > 0 ) {
write(1, tmp, READ_CHUNK);
/* To test premature reader exit >>>>>>>>>>>
iso_ring_buffer_reader_close(data->rbuf);
pthread_exit(NULL);
<<<<<<<<<<<<<<<<<<<<<<<<< */
// if (rand() > 2000000000) {
// fprintf(stderr, "Reader sleeping\n");
// sleep(1);
// }
}
fprintf(stderr, "Reader finish: %d\n", res);
iso_ring_buffer_reader_close(data->rbuf);
pthread_exit(NULL);
}
int main(int argc, char **argv)
{
int res;
struct th_data data;
pthread_t reader;
pthread_t writer;
if (argc != 2) {
fprintf(stderr, "Usage: catbuffer /path/to/file\n");
return 1;
}
res = iso_ring_buffer_new(&data.rbuf);
if (res < 0) {
fprintf(stderr, "Can't create buffer\n");
return 1;
}
data.path = argv[1];
res = pthread_create(&writer, NULL, write_function, (void *) &data);
res = pthread_create(&reader, NULL, read_function, (void *) &data);
pthread_join(writer, NULL);
pthread_join(reader, NULL);
fprintf(stderr, "Buffer was %d times full and %d times empty.\n",
iso_ring_buffer_get_times_full(data.rbuf),
iso_ring_buffer_get_times_empty(data.rbuf));
free(data.rbuf);
return 0;
}