X-Git-Url: https://git.dlugolecki.net.pl/?a=blobdiff_plain;f=src%2Fprocess3.c;h=28ecce5dcb6b4076c56447d2d9d1f8a3260e0f40;hb=963f77561737c9098d160a4b1d308c71ab0fdef8;hp=8b4f8264f39a3621f6dc0f267b6f53e8339e0f63;hpb=c0975e5a6af7b478563193dac7c3484b4430d3a3;p=wsti_so.git

diff --git a/src/process3.c b/src/process3.c
index 8b4f826..28ecce5 100644
--- a/src/process3.c
+++ b/src/process3.c
@@ -1,27 +1,119 @@
 #include <stdio.h>
 
+/* exit.. */
+#include <stdlib.h>
+/* strsignal... */
+#include <string.h>
+
 /* open/read/write/close */
 #include <fcntl.h>
 
 /* Signals handling.. */
 #include <signal.h>
 
+#include <sys/shm.h>
+#include <sys/msg.h>
+
+/** 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 = 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 != 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(qid, &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));
 	if (signo == SIGUSR1) {
-		fprintf(stderr, "[%s] SIGUSR1!\n", "process1");
+		fprintf(stderr, "[%s] > Notified!\n", "process3");
+		struct queue_message msg;
+		/* Check queues from both other processes */
+		if (msgrcv(qid, &msg, sizeof(int), 3, 0) > 0) {
+			fprintf(stderr, "[%s] > Notified with value: %s!\n", "process3", strsignal(msg.signo[0]));
+			raise(msg.signo[0]);
+		}
+		else if (msgrcv(qid, &msg, sizeof(int), 3, 0) > 0) {
+			fprintf(stderr, "[%s] > Notified with value: %s!\n", "process3", strsignal(msg.signo[0]));
+			raise(msg.signo[0]);
+		}
 	}
-	else if (signo == SIGUSR2) {
-		fprintf(stderr, "[%s] SIGUSR2!\n", "process1");
+	else if (signo == SIGTERM) {
+		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);
+		exit(0);
 	}
-	else if (signo == SIGINT) {
-		fprintf(stderr, "[%s] SIGINT!\n", "process1");
+	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] SIGCONT!\n", "process1");
+		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);
 	}
 }
 
@@ -30,12 +122,6 @@ 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 +136,32 @@ 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), 0666);
+
+	processes = (struct message *)shmat(shmid, NULL, 0);
+	processes->pids[2] = getpid();
+
+	fprintf(stderr, "[%s] Shared pid: %d\n", "process3", getpid());
+
+	/**
+	 * Register message queue to communicate with other processes
+	 */
+	qid = msgget(qkey, 0666);
+
 	/* Reading from process2 */
 	read_descriptor = open(read_pipe, O_RDONLY);
 
@@ -77,6 +179,7 @@ int main(void) {
 		}
 	}
 
+	/* Release resources in normal program flow exit. */
 	close(read_descriptor);
 
 	return 0;