From ff94a13ba95f9ce6697ef47c95071dd9b2ab424e Mon Sep 17 00:00:00 2001
From: Guo Wenxue <guowenxue@gmail.com>
Date: Wed, 05 Dec 2018 21:23:23 +0800
Subject: [PATCH] Add IPC singal.c sample code
---
ch6_ipc/signal.c | 76 ++++++++++++++++++++++++++++++++++++++
1 files changed, 76 insertions(+), 0 deletions(-)
diff --git a/ch6_ipc/signal.c b/ch6_ipc/signal.c
new file mode 100644
index 0000000..17230e5
--- /dev/null
+++ b/ch6_ipc/signal.c
@@ -0,0 +1,76 @@
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <signal.h>
+
+
+int g_child_stop = 0;
+int g_parent_run = 0;
+
+void sig_child(int signum)
+{
+ if( SIGUSR1 == signum )
+ {
+ g_child_stop = 1;
+ }
+}
+
+void sig_parent(int signum)
+{
+ if( SIGUSR2 == signum )
+ {
+ g_parent_run = 1;
+ }
+}
+
+int main(int argc, char **argv)
+{
+ int pid;
+ int wstatus;
+
+ signal(SIGUSR1, sig_child);
+ signal(SIGUSR2, sig_parent);
+
+ if( (pid=fork()) < 0 )
+ {
+ printf("Create child process failure: %s\n", strerror(errno));
+ return -2;
+ }
+ else if(pid == 0)
+ {
+ /* child process can do something first here, then tell parent process to start running */
+
+ printf("Child process start running and send parent a signal\n");
+ kill(getppid(), SIGUSR2);
+
+ while( !g_child_stop )
+ {
+ sleep(1);
+ }
+
+ printf("Child process receive signal from parent and exit now\n");
+ return 0;
+ }
+
+ printf("Parent hangs up untill receive signal from child!\n");
+ while( !g_parent_run )
+ {
+ sleep(1);
+ }
+
+ /* parent process can do something here, then tell child process to exit */
+
+ printf("Parent start running now and send child a signal to exit\n");
+ kill(pid, SIGUSR1);
+
+ /* parent wait child process exit */
+ wait(&wstatus);
+ printf("Parent wait child process die and exit now\n");
+
+ return 0;
+}
+
+
--
Gitblit v1.9.1