X-Git-Url: https://git.dlugolecki.net.pl/?a=blobdiff_plain;ds=sidebyside;f=src%2Fprocess3.c;h=54bb6587370a53648f0aecbc63a6e2b299ec5176;hb=b1c3c5ca4ac63d8e7f92cc130a75d2322b8a28d8;hp=8b4f8264f39a3621f6dc0f267b6f53e8339e0f63;hpb=c0975e5a6af7b478563193dac7c3484b4430d3a3;p=wsti_so.git diff --git a/src/process3.c b/src/process3.c index 8b4f826..54bb658 100644 --- a/src/process3.c +++ b/src/process3.c @@ -1,27 +1,93 @@ #include +/* exit.. */ +#include + /* open/read/write/close */ #include /* Signals handling.. */ #include +#include + +/** Named pipe used to communicate with process2 */ +char * read_pipe = "/tmp/process2pipe"; + +/** Descriptor of input pipe */ +int read_descriptor; + + +/** + * Shared memory variables + */ +/** + * Memory key for processes. Must be same between all processes to properly + * communicate. + */ +key_t shmkey = 18912; +/** + * Id of the shared memory + */ +int shmid; + +/** + * Message shared by processes. Contains array of process IDs + */ +struct message { + pid_t pids[3]; +}; + +struct message * processes = NULL; + +/** + * Message queue variables + */ +key_t qkey; +int qid_input; + +int qid_output1; +int qid_output2; + +struct queue_message { + int signo; +}; + /** * Handler for signals. */ void sig_handler(int signo) { + fprintf(stderr, "[%s] Received %s!\n", "process3", strsignal(signo)); if (signo == SIGUSR1) { - fprintf(stderr, "[%s] SIGUSR1!\n", "process1"); + fprintf(stderr, "[%s] > Notified!\n", "process3"); } - else if (signo == SIGUSR2) { - fprintf(stderr, "[%s] SIGUSR2!\n", "process1"); + else if (signo == SIGTERM) { + int i = 0; + struct queue_message msg; + msg.signo = signo; + + fprintf(stderr, "[%s] > Releasing resources\n", "process3"); + close(read_descriptor); + for (; i < 3; i++) { + pid_t pid = processes->pids[i]; + fprintf(stderr, "[%s] Process %d, PID: %d\n", "process3", i, pid); + // Bleh + if (i != 2) { + msgsnd(pid, &msg, sizeof(msg)); + kill(pid, SIGUSR1); + } + } + exit(0); } - else if (signo == SIGINT) { - fprintf(stderr, "[%s] SIGINT!\n", "process1"); + else if (signo == SIGTSTP) { + fprintf(stderr, "[%s] > Closing pipe\n", "process3"); + close(read_descriptor); + raise (SIGSTOP); } else if (signo == SIGCONT) { - fprintf(stderr, "[%s] SIGCONT!\n", "process1"); + fprintf(stderr, "[%s] > Opening pipe\n", "process3"); + read_descriptor = open(read_pipe, O_RDONLY); } } @@ -30,12 +96,6 @@ void sig_handler(int signo) * grabbed data to the standard output. */ int main(void) { - /** Named pipe used to communicate with process2 */ - char * read_pipe = "/tmp/process2pipe"; - - /** Descriptor of input pipe */ - int read_descriptor; - /** Buffer used for storing data from input pipe */ int buffer = 0; @@ -50,16 +110,37 @@ int main(void) { if (signal(SIGUSR1, sig_handler) == SIG_ERR) { fprintf(stderr, "can't catch SIGUSR1\n"); } - if (signal(SIGUSR2, sig_handler) == SIG_ERR) { - fprintf(stderr, "can't catch SIGUSR2\n"); + if (signal(SIGTERM, sig_handler) == SIG_ERR) { + fprintf(stderr, "can't catch SIGTERM\n"); } - if (signal(SIGINT, sig_handler) == SIG_ERR) { - fprintf(stderr, "can't catch SIGINT\n"); + if (signal(SIGTSTP, sig_handler) == SIG_ERR) { + fprintf(stderr, "can't catch SIGTSTP\n"); } if (signal(SIGCONT, sig_handler) == SIG_ERR) { fprintf(stderr, "can't catch SIGCONT\n"); } + /* + * Register memory to share with other processes, and pass current + * process id to the array. + */ + shmid = shmget(shmkey, sizeof(struct message), IPC_CREAT | 0666); + + processes = (struct message *)shmat(shmid, NULL, 0); + processes->pids[2] = getpid(); + + fprintf(stderr, "[%s] Shared pid: %d\n", "process3", getpid()); + + sleep(1); + /** + * Register message queue to communicate with other processes + */ + qkey = getpid(); + qid_input = msgget(qkey, IPC_CREAT | 0666); + + qid_output1 = msgget(processes->pids[1], IPC_CREAT | 0666); + qid_output2 = msgget(processes->pids[2], IPC_CREAT | 0666); + /* Reading from process2 */ read_descriptor = open(read_pipe, O_RDONLY); @@ -77,6 +158,7 @@ int main(void) { } } + /* Release resources in normal program flow exit. */ close(read_descriptor); return 0;