Replace SIGINT with SIGTSTP.

[wsti_so.git] / src / process3.c

diff --git a/src/process3.c b/src/process3.c
index 4568d97d1e3c4ee1280221fbf7f23ef1cd7f57e2..b75f903af10e363d5c96d07000fa22609322f025 100644 (file)
--- a/src/process3.c
+++ b/src/process3.c
@@ -1,30 +1,75 @@
 #include <stdio.h>
 
+/* exit.. */
+#include <stdlib.h>
+
 /* open/read/write/close */
 #include <fcntl.h>
 
+/* Signals handling.. */
+#include <signal.h>
+
+/** Named pipe used to communicate with process2 */
+char * read_pipe = "/tmp/process2pipe";
+
+/** Descriptor of input pipe */
+int read_descriptor;
+
+/**
+ * Handler for signals.
+ */
+void sig_handler(int signo)
+{
+       fprintf(stderr, "[%s] Received %s!\n", "process3", strsignal(signo));
+       if (signo == SIGUSR1) {
+       }
+       else if (signo == SIGTERM) {
+               fprintf(stderr, "[%s] > Releasing resources\n", "process3");
+               close(read_descriptor);
+               exit(0);
+       }
+       else if (signo == SIGTSTP) {
+               fprintf(stderr, "[%s] > Closing pipe\n", "process3");
+               close(read_descriptor);
+       }
+       else if (signo == SIGCONT) {
+               fprintf(stderr, "[%s] > Opening pipe\n", "process3");
+               read_descriptor = open(read_pipe, O_RDONLY);
+       }
+}
+
 /**
  * Program grabs data (calculated number of characters) from process2 and prints
  * 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;
        
        /** Stores number of bytes read from input pipe in current iteration */
        ssize_t count = 0;
 
+       fprintf(stderr, "[%s] Init!\n", "process3");
+
+       /**
+        * 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");
+       }
+
        /* Reading from process2 */
        read_descriptor = open(read_pipe, O_RDONLY);
 
-       fprintf(stderr, "[%s] Init!\n", "process3");
-
        while(1) {
                /* Read data from input pipe */
                count = read(read_descriptor, &buffer, sizeof(int));
@@ -39,6 +84,7 @@ int main(void) {
                }
        }
 
+       /* Release resources in normal program flow exit. */
        close(read_descriptor);
 
        return 0;