From a45c92f4143fa4b3ec8afb51f99681f8b6b078d6 Mon Sep 17 00:00:00 2001
From: gumartinm <gu.martinm@gmail.com>
Date: Tue, 18 Dec 2012 06:25:48 +0100
Subject: [PATCH] Unblock SIGCHLD signal in child process.
---
Daemon/javafork.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/Daemon/javafork.c b/Daemon/javafork.c
index b6350aa..fff50ec 100644
--- a/Daemon/javafork.c
+++ b/Daemon/javafork.c
@@ -555,6 +555,7 @@ int fork_system(int socket, unsigned char *command, int *returnstatus)
int childreturnstatus;
int returnValue = 0; /*return value from this function can be caught by upper layers,*/
/*OK by default*/
+ sigset_t unBlockMask; /*Used by the child process in order to unblock the SIGCHLD signal, which was blocked by the main process.*/
/*Value by default*/
@@ -578,6 +579,27 @@ int fork_system(int socket, unsigned char *command, int *returnstatus)
if (pid == 0) {
/*Child process*/
/*It has to launch another one using system or execve*/
+ /*TODO: close every fd but 0, 1, 2 (or my pipes) and the read end of my pipes.*/
+
+ /*Unblock SIGCHLD*/
+ if (sigemptyset(&unBlockMask) < 0) {
+ syslog (LOG_ERR, "Unblock SIGCHLD empty mask: %m");
+ /*Going to zombie state, hopefully waitpid will catch it*/
+ exit(-1);
+ }
+ if (sigaddset(&unBlockMask, SIGCHLD) <0) {
+ syslog (LOG_ERR, "Unblock SIGCHLD sigaddset mask: %m");
+ /*Going to zombie state, hopefully waitpid will catch it*/
+ exit(-1);
+ }
+ /*Should I use pthread_sigmask?*/
+ if (sigprocmask(SIG_UNBLOCK, &unBlockMask, NULL) == -1) {
+ syslog (LOG_ERR, "Unblock sigprocmask failed: %m");
+ /*Going to zombie state, hopefully waitpid will catch it*/
+ exit(-1);
+ }
+
+ /*Attach pipes to the stderr and stdout streams*/
if ((TEMP_FAILURE_RETRY(dup2(out[1], 1)) < 0) || (TEMP_FAILURE_RETRY(dup2(err[1], 2)) < 0)) {
syslog (LOG_ERR, "child dup2 failed: %m");
/*Going to zombie state, hopefully waitpid will catch it*/
@@ -600,6 +622,7 @@ int fork_system(int socket, unsigned char *command, int *returnstatus)
else {
/*Parent process*/
/*It sends data to the Java client using a TCP connection.*/
+ /*TODO: close the write end of my pipes.*/
polls[0].fd=out[0];
polls[1].fd=err[0];
polls[0].events = polls[1].events = POLLIN;
--
2.1.4