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#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <fcntl.h> /* Obtain O_* constant definitions */
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "main.h"
#include "child.h"
#include "parent.h"
#include "common.h"
static char* app_name;
void usage( FILE* output ) {
fprintf(output, "usage: %s -p <x>\n", app_name);
fprintf(output, "`x` must be int between 1 and %d\n", MAX_X);
}
void close_redundant_pipes( dist_info_t *info, uint8_t id ) {
uint8_t i, j;
for(i = 0; i < info->proccnt; i++) {
uint8_t base = i * (info->proccnt-1); // base of block of pipes for this process
if( i == id ) {
for(j = 0; j < info->proccnt - 1; j++) {
// fprintf( stderr, "Read descriptor %d closed for id %d\n", info->pipes[base + j][0], id );
close( info->pipes[base + j][0] ); // close only read descriptor of ( ID -> Y )
}
} else {
uint8_t idx = ( id > i ? id - 1: id ); // index number in block of pipes for ( X -> ID )
for(j = 0; j < info->proccnt - 1; j++) {
if( j == idx ) {
close( info->pipes[base + j][1] ); // close only write descriptor of ( X -> ID )
// fprintf( stderr, "Write descriptor %d of pipe (%d -> %d) closed for id %d\n", info->pipes[base + j][1], i, id, id );
} else {
// fprintf( stderr, "LOL\n\n\n");
close( info->pipes[base + j][0] ); // close read descriptor of ( X -> Y, where Y != ID )
close( info->pipes[base + j][1] ); // close write descriptor of ( X -> Y, where Y != ID )
}
}
}
}
}
int main(int argc, char* argv[]) {
uint8_t i;
dist_info_t info;
app_name = argv[0];
if( argc != 3 || strcmp( argv[1], "-p") != 0 ) {
usage(stdout);
return 1;
}
// fill info about distributed network
info.x = atoi(argv[2]);
if( info.x < 0 || info.x > MAX_X ) {
usage(stdout);
return 1;
}
info.proccnt = info.x + 1;
info.parent_pid = getpid();
info.events_log = fopen( events_log, "w" );
info.pipes_log = fopen( pipes_log, "w" );
// open all (N * (N-1)) pipes for a full mesh topology
for( i = 0; i < info.proccnt * (info.proccnt - 1); i++ ) {
pipe2( info.pipes[i], O_NONBLOCK | O_DIRECT );
fprintf( info.pipes_log, "Opened pipe #%d (%d;%d)\n", i, info.pipes[i][0], info.pipes[i][1] );
}
fclose( info.pipes_log );
for( i = 1; i < info.proccnt; i++ ) {
pid_t pid = fork();
switch(pid) {
case 0:
/* Child branch */
child_workflow( &info, i );
exit(0);
break;
case -1:
/* Error */
perror("fork");
return 1;
default:
break;
}
}
parent_workflow( &info );
return 0;
}
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