Using only one message queue.

[wsti_so.git] / src / process1.c

diff --git a/src/process1.c b/src/process1.c
index b28563f4102faf831cf12deecd2ff440eb3b0216..fbbfa40c1b2d5f848ea279ce4ce954b106719062 100644 (file)
--- a/src/process1.c
+++ b/src/process1.c
@@ -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 */
@@ -46,16 +47,60 @@ struct message {
 
 struct message * processes = NULL;
 
+/**
+ * Message queue variables
+ */
+key_t qkey = 12356;
+int qid;
+
+struct queue_message {
+       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(qid, &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", "process1");
+               struct queue_message msg;
+               /* Check queues from both other processes */
+               if (msgrcv(qid, &msg, sizeof(int), 1, 0) > 0) {
+                       fprintf(stderr, "[%s] > Notified with value: %s!\n", "process1", strsignal(msg.signo[0]));
+                       raise(msg.signo[0]);
+               }
+               else if (msgrcv(qid, &msg, sizeof(int), 1, 0) > 0) {
+                       fprintf(stderr, "[%s] > Notified with value: %s!\n", "process1", strsignal(msg.signo[0]));
+                       raise(msg.signo[0]);
+               }
        }
        else if (signo == SIGTERM) {
-               int i = 0;
+               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);
                unlink(write_pipe);
@@ -64,9 +109,6 @@ void sig_handler(int signo)
                        free(buffer);
                        buffer = NULL;
                }
-               for (; i < 3; i++) {
-                       fprintf(stderr, "[%s] Process %d, PID: %d\n", "process3", i, processes->pids[i]);
-               }
                exit(0);
        }
        else if (signo == SIGTSTP) {
@@ -127,6 +169,13 @@ int main(void) {
        processes = (struct message *)shmat(shmid, NULL, 0);
        processes->pids[0] = getpid();
 
+       fprintf(stderr, "[%s] Shared pid: %d\n", "process1", getpid());
+
+       /**
+        * Register message queue to communicate with other processes
+        */
+       qid = msgget(qkey, IPC_CREAT | 0666);
+       
        mkfifo(write_pipe, 0666);
 
        file_descriptor = open(write_pipe, O_WRONLY);