From 76def9a53192c9748808616eaf49f6a476385f17 Mon Sep 17 00:00:00 2001
From: Nathan Straz <nstraz@redhat.com>
Date: Fri, 4 Oct 2013 12:21:34 -0400
Subject: Remove child signal handling

Instead of moving the setup for SIGCHLD handling, I'm removing it.
waitpid() isn't that expensive and we know the pid we are waiting for.
---
 qarshd.c | 24 +++++-------------------
 1 file changed, 5 insertions(+), 19 deletions(-)

diff --git a/qarshd.c b/qarshd.c
index dc53d21..255defe 100644
--- a/qarshd.c
+++ b/qarshd.c
@@ -53,7 +53,6 @@ int dopause = 0;
 /* Globals */
 const int qinfd = 0; /* qarshd in file descriptor */
 const int qoutfd = 1; /* qarshd out file descriptor */
-int child_exitted = 0;
 pid_t child_pid;
 sigset_t orig_sigmask;
 int childfds[3] = { -1, -1, -1 }; /* pipes to child for stdin/stdout/stderr */
@@ -103,7 +102,6 @@ setup_user(char *user, char *group)
 void
 sig_handler(int sig)
 {
-	if (sig == SIGCHLD) child_exitted++;
 }
 
 pid_t 
@@ -129,7 +127,6 @@ run_cmd(const char *cmd)
 
 	if (pid == 0) { /* child */
 		setpgrp();
-		sigprocmask(SIG_SETMASK, &orig_sigmask, NULL);
 
 		/* Connect stdin, stdout, and stderr to parent's pipes */
 		dup2(parentfds[0], fileno(stdin));
@@ -240,9 +237,7 @@ handle_qarsh()
 {
 	fd_set rfds, wfds;
 	int nfd, maxfd;
-	struct timespec timeout;
-	sigset_t sigmask;
-	struct sigaction sa;
+	struct timeval timeout;
 	int child_status;
 	struct qa_packet *qp = NULL, *rp = NULL;
 	int allowed_out = 0, allowed_err = 0; /* number of bytes we can send to client */
@@ -252,13 +247,6 @@ handle_qarsh()
 	int eof_in = 0;		/* Have we seen EOF on stdin yet? */
 	int nbytes;
 
-	sigemptyset(&sigmask);
-	sigaddset(&sigmask, SIGCHLD);
-	sigprocmask(SIG_BLOCK, &sigmask, &orig_sigmask);
-	sa.sa_handler = sig_handler;
-	sa.sa_mask = sigmask;
-	sa.sa_flags = SA_RESTART;
-	sigaction(SIGCHLD, &sa, NULL);
 	signal(SIGPIPE, SIG_IGN);
 
 	qp = make_qp_data_allow(0, QARSHD_BUFSIZE);
@@ -268,7 +256,7 @@ handle_qarsh()
 	for (;;) {
 
 		timeout.tv_sec = 3;
-		timeout.tv_nsec = 0;
+		timeout.tv_usec = 0;
 		FD_ZERO(&rfds); FD_ZERO(&wfds);
 		FD_SET(qinfd, &rfds);
 		maxfd = qinfd;
@@ -285,15 +273,13 @@ handle_qarsh()
 			maxfd = childfds[2] > maxfd ? childfds[2] : maxfd;
 		}
 
-		nfd = pselect(maxfd+1, &rfds, &wfds, NULL, &timeout, &orig_sigmask);
+		nfd = select(maxfd+1, &rfds, &wfds, NULL, &timeout);
 
-		if (child_exitted) {
-			waitpid(child_pid, &child_status, 0);
-			child_exitted--;
-			child_pid = 0;
+		if (child_pid && waitpid(child_pid, &child_status, WNOHANG) == child_pid) {
 			rp = make_qp_cmdexit(child_pid, child_status);
 			send_packet(qoutfd, rp);
 			qpfree(rp);
+			child_pid = 0;
 		}
 		if (nfd < 0) {
 			if (errno == EINTR) {
-- 
cgit