X-Git-Url: https://git.dlugolecki.net.pl/?a=blobdiff_plain;f=src%2Fprocess1.c;h=b28563f4102faf831cf12deecd2ff440eb3b0216;hb=f0a7f7a71896b25cc524598e5472c821f987a71c;hp=d0b8e19135969cf98be9cc36f7c305c781107ac8;hpb=edc26e7336f1ee79ab0ca631dbab8e791812fd21;p=wsti_so.git

diff --git a/src/process1.c b/src/process1.c
index d0b8e19..b28563f 100644
--- a/src/process1.c
+++ b/src/process1.c
@@ -5,9 +5,81 @@
 /* open/read/write/close */
 #include <fcntl.h>
 
+/* Signals handling.. */
+#include <signal.h>
+
+#include <sys/shm.h>
+
+
 /** If buffer is too small to hold entire string, it is incremented by this value */
 #define BUFFER_STEP 16
 
+/** Buffer used to store line of characters */
+char * buffer = NULL;
+
+/** Named pipe used to communnicate with process2 */
+char * write_pipe = "/tmp/process1pipe";
+
+/** File descriptor of pipe */
+int file_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;
+
+/**
+ * Handler for signals.
+ */
+void sig_handler(int signo)
+{
+	fprintf(stderr, "[%s] Received %s!\n", "process1", strsignal(signo));
+	if (signo == SIGUSR1) {
+	}
+	else if (signo == SIGTERM) {
+		int i = 0;
+		fprintf(stderr, "[%s] > Releasing resources\n", "process1");
+		close(write_pipe);
+		unlink(write_pipe);
+
+		if (buffer) {
+			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) {
+		fprintf(stderr, "[%s] > Closing pipe\n", "process1");
+		close(write_pipe);
+		raise (SIGSTOP);
+	}
+	else if (signo == SIGCONT) {
+		fprintf(stderr, "[%s] > Opening pipe\n", "process1");
+		file_descriptor = open(write_pipe, O_WRONLY);
+	}
+}
+
 /**
  * Program reads entire lines of text from the standard input and pass them
  * to the process2 using created pipe.
@@ -16,9 +88,6 @@ int main(void) {
 	/** Currently fetched from stdin character */
 	int c;
 
-	/** Buffer used to store line of characters */
-	char * buffer = NULL;
-
 	/** Current buffer length*/
 	int buffer_length = 0;
 
@@ -31,16 +100,37 @@ int main(void) {
 	 */
 	char * tmp = NULL;
 
-	/** Named pipe used to communnicate with process2 */
-	char * write_pipe = "/tmp/process1pipe";
+	fprintf(stderr, "[%s] Init!\n", "process1");
 
-	/** File descriptor of pipe */
-	int file_descriptor;
+	/**
+	 * Register signals handled by process
+	 */
+	if (signal(SIGUSR1, sig_handler) == SIG_ERR) {
+		fprintf(stderr, "can't catch SIGUSR1\n");
+	}
+	if (signal(SIGTERM, sig_handler) == SIG_ERR) {
+		fprintf(stderr, "can't catch SIGTERM\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[0] = getpid();
 
 	mkfifo(write_pipe, 0666);
 
 	file_descriptor = open(write_pipe, O_WRONLY);
-	
+
 	do {
 		c = fgetc(stdin);
 
@@ -97,6 +187,7 @@ int main(void) {
 		}
 	} while(c != EOF);
 
+	/* Release resources in normal program flow exit. */
 	close(write_pipe);
 	unlink(write_pipe);