58 lines
2.2 KiB
C
58 lines
2.2 KiB
C
/**
|
|
* @file supervisor.c
|
|
* @author Ivaylo Ivanov 11777707
|
|
* @date 11.01.2018
|
|
*
|
|
* @brief Supervisor program module.
|
|
*
|
|
* The supervisor sets up the shared memory and the semaphores and initializes the circular buffer required
|
|
* for the communication with the generators. It then waits for the generators to write solutions to the
|
|
* circular buffer.
|
|
* The supervisor program takes no arguments.
|
|
* Once initialization is complete, the supervisor reads the solutions from the circular buffer and remembers the best solution so far, i.e. the solution with the least edges. Every time a better solution than the
|
|
* previous best solution is found, the supervisor writes the new solution to standard output. If a generator
|
|
* writes a solution with 0 edges to the circular buffer, then the graph is acyclic and the supervisor terminates. Otherwise the supervisor keeps reading results from the circular buffer until it receives a SIGINT
|
|
* or a SIGTERM signal.
|
|
* Before terminating, the supervisor notifies all generators that they should terminate as well. This can
|
|
* be done by setting a variable in the shared memory, which is checked by the generator processes before
|
|
* writing to the buffer. The supervisor then unlinks all shared resources and exits.
|
|
*
|
|
* SYNOPSIS
|
|
* supervisor
|
|
*
|
|
**/
|
|
#include "shared/shm.c"
|
|
#include "shared/sem.c"
|
|
#include "shared/structs.c"
|
|
|
|
int main(int argc, char *argv[]) {
|
|
if(argc > 1) {
|
|
fprintf(stderr, "ERROR: Command takes no arguments");
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
/// Open shared memory objects
|
|
int buffer_shmfd = create_shmfd(BUFFER_SHM_NAME);
|
|
truncate_shm(buffer_shmfd, BUFF_SIZE);
|
|
circ_buffer = (buffer_t *)open_shm(buffer_shmfd, sizeof(buffer_t));
|
|
|
|
/// Open semaphores
|
|
free_sem = open_sem(FREE_SEM_NAME, BUFF_SIZE);
|
|
used_sem = open_sem(USED_SEM_NAME, 0);
|
|
mutex = open_sem(MUTEX_NAME, 1);
|
|
|
|
|
|
/// Close and destory semaphores
|
|
close_sem(free_sem);
|
|
close_sem(used_sem);
|
|
close_sem(mutex);
|
|
|
|
destroy_sem(FREE_SEM_NAME);
|
|
destroy_sem(USED_SEM_NAME);
|
|
destroy_sem(MUTEX_NAME);
|
|
|
|
/// Close and destroy shared memory objects
|
|
close_shm(circ_buffer, sizeof(buffer_t));
|
|
destroy_shm(BUFFER_SHM_NAME, buffer_shmfd);
|
|
}
|