Save nearly working queues.
authorRafał Długołęcki <rafal@dlugolecki.net.pl>
Sat, 21 Jun 2014 17:51:59 +0000 (19:51 +0200)
committerRafał Długołęcki <rafal@dlugolecki.net.pl>
Sat, 21 Jun 2014 17:51:59 +0000 (19:51 +0200)
src/bootstrap.c
src/process1.c
src/process2.c
src/process3.c

index bca693c25076765134806010d76b6f5331d4dbee..070dac8f88ad96961ddcd2187c9b0e937543f9c5 100644 (file)
@@ -64,6 +64,7 @@ int main(void) {
                        fprintf(stderr, "[%s] Something went wrong when forking %s. Error: %s\n",
                                "bootstrap", processes[i], strerror(errno));
                }
+               sleep(1);
        }
 
        /* All processes should be now spawned. Close bootstrap program. */
index 41e0ea4729508bc71bcdb70f7cf423ace48942f3..2492ebecfe874f5ed4b4bae357b8e05aa56122f0 100644 (file)
@@ -9,6 +9,7 @@
 #include <signal.h>
 
 #include <sys/shm.h>
+#include <sys/msg.h>
 
 
 /** If buffer is too small to hold entire string, it is incremented by this value */
@@ -56,22 +57,54 @@ int qid_output1;
 int qid_output2;
 
 struct queue_message {
-       int signo;
+       long mtype;
+       int signo[1];
 };
 
+void notify_other_processes(int signo) {
+       int i = 0;
+       struct queue_message msg;
+       msg.signo[0] = signo;
+
+       for (; i < 3; i++) {
+               pid_t pid = processes->pids[i];
+               // Bleh
+               if (i != 0 && pid != 0) {
+                       msg.mtype = i+1;
+                       fprintf(stderr, "[%s] Sending message of type (%d) with value %d\n", "process1", msg.mtype, msg.signo[0]);
+                       msgsnd(pid, &msg, sizeof(int), 0);
+                       fprintf(stderr, "[%s] Sending signal %s (%d) to PID: %d\n", "process1", strsignal(SIGUSR1), SIGUSR1, pid);
+                       kill(pid, SIGUSR1);
+               }
+       }
+}
+
 /**
  * Handler for signals.
  */
 void sig_handler(int signo)
 {
        fprintf(stderr, "[%s] Received %s!\n", "process1", strsignal(signo));
+
        if (signo == SIGUSR1) {
-               fprintf(stderr, "[%s] > Notified!\n", "process3");
+               fprintf(stderr, "[%s] > Notified!\n", "process1");
+               struct queue_message msg;
+               /* Check queues from both other processes */
+               if (msgrcv(processes->pids[1], &msg, sizeof(int), 1, 0) > 0) {
+                       fprintf(stderr, "[%s] > Notified with value: %s!\n", "process1", strsignal(msg.signo[0]));
+                       raise(msg.signo[0]);
+                       break;
+               }
+               else if (msgrcv(processes->pids[2], &msg, sizeof(int), 1, 0) > 0) {
+                       fprintf(stderr, "[%s] > Notified with value: %s!\n", "process1", strsignal(msg.signo[0]));
+                       raise(msg.signo[0]);
+                       break;
+               }
        }
        else if (signo == SIGTERM) {
-               int i = 0;
-               struct queue_message msg;
-               msg.signo = signo;
+               fprintf(stderr, "[%s] > Signalling other processes..\n", "process1");
+               processes->pids[1] = 0;
+               notify_other_processes(signo);
 
                fprintf(stderr, "[%s] > Releasing resources\n", "process1");
                close(write_pipe);
@@ -81,15 +114,6 @@ void sig_handler(int signo)
                        free(buffer);
                        buffer = NULL;
                }
-               for (; i < 3; i++) {
-                       pid_t pid = processes->pids[i];
-                       fprintf(stderr, "[%s] Process %d, PID: %d\n", "process3", i, pid);
-                       // Bleh
-                       if (i != 0) {
-                               msgsnd(pid, &msg, sizeof(msg));
-                               kill(pid, SIGUSR1);
-                       }
-               }
                exit(0);
        }
        else if (signo == SIGTSTP) {
@@ -152,7 +176,6 @@ int main(void) {
 
        fprintf(stderr, "[%s] Shared pid: %d\n", "process1", getpid());
 
-       sleep(1);
        /**
         * Register message queue to communicate with other processes
         */
index d8c294bf6f20673ebe76684ecb8c09ca7f8dda48..ca2b3b2d5dd74fa51301859e4fa58a6d62cb2de1 100644 (file)
@@ -1,6 +1,8 @@
 #include <stdio.h>
 /* exit.. */
 #include <stdlib.h>
+/* strsignal... */
+#include <string.h>
 
 /* open/read/write/close */
 #include <fcntl.h>
@@ -59,9 +61,28 @@ int qid_output1;
 int qid_output2;
 
 struct queue_message {
-       int signo;
+       long mtype;
+       int signo[1];
 };
 
+void notify_other_processes(int signo) {
+       int i = 0;
+       struct queue_message msg;
+       msg.signo[0] = signo;
+
+       for (; i < 3; i++) {
+               pid_t pid = processes->pids[i];
+               // Bleh
+               if (i != 1 && pid != 0) {
+                       msg.mtype = i+1;
+                       fprintf(stderr, "[%s] Sending message of type (%d) with value %d\n", "process1", msg.mtype, msg.signo[0]);
+                       msgsnd(pid, &msg, sizeof(msg), 0);
+                       fprintf(stderr, "[%s] Sending signal %s (%d) to PID: %d\n", "process2", strsignal(SIGUSR1), SIGUSR1, pid);
+                       kill(pid, SIGUSR1);
+               }
+       }
+}
+
 /**
  * Handler for signals.
  */
@@ -70,37 +91,45 @@ void sig_handler(int signo)
        fprintf(stderr, "[%s] Received %s!\n", "process2", strsignal(signo));
        if (signo == SIGUSR1) {
                fprintf(stderr, "[%s] > Notified!\n", "process2");
+               struct queue_message msg;
+               /* Check queues from both other processes */
+               if (msgrcv(processes->pids[0], &msg, sizeof(int), 2, 0) > 0) {
+                       fprintf(stderr, "[%s] > Notified with value: %s!\n", "process2", strsignal(msg.signo[0]));
+                       raise(msg.signo[0]);
+                       break;
+               }
+               else if (msgrcv(processes->pids[2], &msg, sizeof(int), 2, 0) > 0) {
+                       fprintf(stderr, "[%s] > Notified with value: %s!\n", "process2", strsignal(msg.signo[0]));
+                       raise(msg.signo[0]);
+                       break;
+               }
        }
        else if (signo == SIGTERM) {
-               int i = 0;
-               struct queue_message msg;
-               msg.signo = signo;
+               fprintf(stderr, "[%s] > Signalling other processes..\n", "process2");
+               processes->pids[1] = 0;
+               notify_other_processes(signo);
 
                fprintf(stderr, "[%s] > Releasing resources\n", "process2");
                close(read_descriptor);
                close(write_descriptor);
                unlink(write_descriptor);
-               for (; i < 3; i++) {
-                       pid_t pid = processes->pids[i];
-                       fprintf(stderr, "[%s] Process %d, PID: %d\n", "process2", i, pid);
-                       // Bleh
-                       if (i != 1) {
-                               msgsnd(pid, &msg, sizeof(msg));
-                               kill(pid, SIGUSR1);
-                       }
-               }
                exit(0);
        }
        else if (signo == SIGTSTP) {
-               fprintf(stderr, "[%s] > Closing pipes\n", "process2");
+               fprintf(stderr, "[%s] > Close reading pipe\n", "process2");
                close(read_descriptor);
+               notify_other_processes(signo);
+               fprintf(stderr, "[%s] > Close writing pipe\n", "process2");
                close(write_descriptor);
                raise (SIGSTOP);
        }
        else if (signo == SIGCONT) {
+               fprintf(stderr, "[%s] > Signalling other processes..\n", "process2");
+               notify_other_processes(signo);
+
                fprintf(stderr, "[%s] > Opening pipes\n", "process2");
-               read_descriptor = open(read_pipe, O_RDONLY);
                write_descriptor = open(write_pipe, O_WRONLY);
+               read_descriptor = open(read_pipe, O_RDONLY);
        }
 }
 
@@ -147,14 +176,13 @@ int main(void) {
         * Register memory to share with other processes, and pass current
         * process id to the array.
         */
-       shmid = shmget(shmkey, sizeof(struct message), IPC_CREAT | 0666);
+       shmid = shmget(shmkey, sizeof(struct message), 0666);
 
        processes = (struct message *)shmat(shmid, NULL, 0);
        processes->pids[1] = getpid();
 
        fprintf(stderr, "[%s] Shared pid: %d\n", "process2", getpid());
 
-       sleep(1);
        /**
         * Register message queue to communicate with other processes
         */
index 54bb6587370a53648f0aecbc63a6e2b299ec5176..a012f4c5616dd525826c03dbbe6cc33723ebde96 100644 (file)
@@ -2,6 +2,8 @@
 
 /* exit.. */
 #include <stdlib.h>
+/* strsignal... */
+#include <string.h>
 
 /* open/read/write/close */
 #include <fcntl.h>
@@ -10,6 +12,7 @@
 #include <signal.h>
 
 #include <sys/shm.h>
+#include <sys/msg.h>
 
 /** Named pipe used to communicate with process2 */
 char * read_pipe = "/tmp/process2pipe";
@@ -50,42 +53,70 @@ int qid_output1;
 int qid_output2;
 
 struct queue_message {
-       int signo;
+       long mtype;
+       int signo[1];
 };
 
+void notify_other_processes(int signo) {
+       int i = 0;
+       struct queue_message msg;
+       msg.signo[0] = signo;
+
+       for (; i < 3; i++) {
+               pid_t pid = processes->pids[i];
+               // Bleh
+               if (i != 2 && pid != 0) {
+                       msg.mtype = i+1;
+                       fprintf(stderr, "[%s] Sending message of type (%d) with value %d\n", "process3", msg.mtype, msg.signo[0]);
+                       msgsnd(pid, &msg, sizeof(int), 0);
+                       fprintf(stderr, "[%s] Sending signal %s (%d) to PID: %d\n", "process3", strsignal(SIGUSR1), SIGUSR1, pid);
+                       kill(pid, SIGUSR1);
+               }
+       }
+}
+
 /**
  * Handler for signals.
  */
 void sig_handler(int signo)
 {
-       fprintf(stderr, "[%s] Received %s!\n", "process3", strsignal(signo));
+       fprintf(stderr, "[%s] Received !\n", "process3");
        if (signo == SIGUSR1) {
                fprintf(stderr, "[%s] > Notified!\n", "process3");
+               struct queue_message msg;
+               /* Check queues from both other processes */
+               if (msgrcv(processes->pids[0], &msg, sizeof(int), 3, 0) > 0) {
+                       fprintf(stderr, "[%s] > Notified with value: %s!\n", "process3", strsignal(msg.signo[0]));
+                       raise(msg.signo[0]);
+                       break;
+               }
+               else if (msgrcv(processes->pids[1], &msg, sizeof(int), 3, 0) > 0) {
+                       fprintf(stderr, "[%s] > Notified with value: %s!\n", "process3", strsignal(msg.signo[0]));
+                       raise(msg.signo[0]);
+                       break;
+               }
        }
        else if (signo == SIGTERM) {
-               int i = 0;
-               struct queue_message msg;
-               msg.signo = signo;
+               fprintf(stderr, "[%s] > Signalling other processes..\n", "process3");
+               processes->pids[2] = 0;
+               notify_other_processes(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 == SIGTSTP) {
+               fprintf(stderr, "[%s] > Signalling other processes..\n", "process3");
+               notify_other_processes(signo);
+
                fprintf(stderr, "[%s] > Closing pipe\n", "process3");
                close(read_descriptor);
                raise (SIGSTOP);
        }
        else if (signo == SIGCONT) {
+               fprintf(stderr, "[%s] > Signalling other processes..\n", "process3");
+               notify_other_processes(signo);
+
                fprintf(stderr, "[%s] > Opening pipe\n", "process3");
                read_descriptor = open(read_pipe, O_RDONLY);
        }
@@ -124,14 +155,13 @@ int main(void) {
         * Register memory to share with other processes, and pass current
         * process id to the array.
         */
-       shmid = shmget(shmkey, sizeof(struct message), IPC_CREAT | 0666);
+       shmid = shmget(shmkey, sizeof(struct message), 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
         */