114 lines
1.9 KiB
C
114 lines
1.9 KiB
C
/**
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* @file supervisor.c
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* @date 2018-05-21
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*
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* @brief Server program which reads solutions and orders them.
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*/
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#include "common.h"
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static const char *pname;
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struct circ_buf *shared;
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struct sigaction sa;
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static volatile sig_atomic_t quit = 0;
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static void sig_handler(int signum)
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{
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quit = 1;
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}
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void usage(void)
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{
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fprintf(stderr, "SYNOPSIS\n"
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"\tsupervisor\n");
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exit(EXIT_FAILURE);
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}
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void initCircBuf()
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{
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shared->quit = 0;
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for (int i = 0; i < MAX_ITEMS; i++) {
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shared->data[i] = 0;
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}
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return;
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}
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int getSolution(sem_t sUsedSpace, sem_t sFreeSpace, int *solution)
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{
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sem_wait(&sUsedSpace);
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int value;
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value = shared->data[shared->head];
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shared->head = (shared->head + 1) % MAX_ITEMS;
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sem_post(&sFreeSpace);
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return value;
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}
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int main(int argc, char *argv[])
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{
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if (argc != 1)
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usage();
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pname = argv[0];
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struct sigaction sa;
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memset(&sa, 0, sizeof(sa));
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sa.sa_handler = &sig_handler;
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sigaction(SIGINT, &sa, NULL);
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sigaction(SIGTERM, &sa, NULL);
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int shmfd = shm_open(SHM_NAME, O_RDWR | O_CREAT, PERMISSION);
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if (shmfd == -1) {
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perror(pname);
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exit(EXIT_FAILURE);
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}
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if (ftruncate(shmfd, sizeof(*shared)) == -1) {
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perror(pname);
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exit(EXIT_FAILURE);
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}
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shared = mmap(NULL, sizeof(*shared), PROT_READ | PROT_WRITE, MAP_SHARED, shmfd, 0);
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if (shared == MAP_FAILED) {
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perror(pname);
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exit(EXIT_FAILURE);
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}
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sem_t *sFreeSpace = sem_open(SEM_FREE_SPACE, O_CREAT | O_EXCL, PERMISSION, MAX_ITEMS);
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sem_t *sUsedSpace = sem_open(SEM_USED_SPACE, O_CREAT | O_EXCL, PERMISSION, 0);
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initCircBuf();
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while (quit == 0) {
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int solution[MAX_ITEMS] = {-1};
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getSolution(*sUsedSpace, *sFreeSpace, solution);
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}
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shared->quit = 1;
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if (munmap(shared, sizeof(*shared)) == -1) {
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perror("munmap");
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exit(EXIT_FAILURE);
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}
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close(shmfd);
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if (shm_unlink(SHM_NAME) == -1) {
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perror("shm_unlink");
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exit(EXIT_FAILURE);
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}
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sem_close(sUsedSpace);
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sem_close(sFreeSpace);
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sem_unlink(SEM_USED_SPACE);
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sem_unlink(SEM_FREE_SPACE);
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return 0;
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}
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