Make opening/closing/releasing resources available from signal handler.

[wsti_so.git] / src / process3.c

diff --git a/src/process3.c b/src/process3.c
index 8b4f8264f39a3621f6dc0f267b6f53e8339e0f63..e75a4fb610d66bae33e895d8271178a8280fe1e7 100644 (file)
--- a/src/process3.c
+++ b/src/process3.c
@@ -1,27 +1,43 @@
 #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)
 {
        if (signo == SIGUSR1) {
-               fprintf(stderr, "[%s] SIGUSR1!\n", "process1");
+               fprintf(stderr, "[%s] Received SIGUSR1!\n", "process3");
        }
-       else if (signo == SIGUSR2) {
-               fprintf(stderr, "[%s] SIGUSR2!\n", "process1");
+       else if (signo == SIGQUIT) {
+               fprintf(stderr, "[%s] Received SIGQUIT!\n", "process3");
+               fprintf(stderr, "[%s] > Releasing resources\n", "process3");
+               close(read_descriptor);
+               exit(0);
        }
        else if (signo == SIGINT) {
-               fprintf(stderr, "[%s] SIGINT!\n", "process1");
+               fprintf(stderr, "[%s] Received SIGINT!\n", "process3");
+               fprintf(stderr, "[%s] > Closing pipe\n", "process2");
+               close(read_descriptor);
        }
        else if (signo == SIGCONT) {
-               fprintf(stderr, "[%s] SIGCONT!\n", "process1");
+               fprintf(stderr, "[%s] Received SIGCONT!\n", "process3");
+               fprintf(stderr, "[%s] > Opening pipe\n", "process2");
+               read_descriptor = open(read_pipe, O_RDONLY);
        }
 }
 
@@ -30,12 +46,6 @@ 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;
        
@@ -50,8 +60,8 @@ 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(SIGQUIT, sig_handler) == SIG_ERR) {
+               fprintf(stderr, "can't catch SIGQUIT\n");
        }
        if (signal(SIGINT, sig_handler) == SIG_ERR) {
                fprintf(stderr, "can't catch SIGINT\n");
@@ -77,6 +87,7 @@ int main(void) {
                }
        }
 
+       /* Release resources in normal program flow exit. */
        close(read_descriptor);
 
        return 0;