From 6969c9fa8293a44daf7ba5a0426573fcd71c1953 Mon Sep 17 00:00:00 2001
From: Andre <maan@p133.(none)>
Date: Tue, 13 Jun 2006 11:41:28 +0200
Subject: [PATCH] mark all fds used for select() as non-blocking

This shouldn't matter much, but there _are_ (rare) situations where
an fd is marked ready for reading, but a subsequent read will block
nevertheless. It's never wrong to use non-blocking fds, so just do it.

This patch also includes a check in para_fd_set() which spots blocking
fds as they are added to the fd sets. This check is commented out
for performance reasons but can easily be activated.
---
 audiod.c    |  2 ++
 dccp.c      |  1 +
 dccp_recv.c |  1 +
 fd.c        | 10 ++++++++++
 http_recv.c |  6 ++++--
 stdin.c     |  1 +
 stdout.c    |  1 +
 7 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/audiod.c b/audiod.c
index 52f4ff4c..90290639 100644
--- a/audiod.c
+++ b/audiod.c
@@ -882,6 +882,7 @@ static int audiod_get_socket(void)
 		exit(EXIT_FAILURE); /* do not unlink socket */
 	}
 	add_close_on_fork_list(fd);
+	mark_fd_nonblock(fd);
 	return fd;
 }
 
@@ -894,6 +895,7 @@ static int open_stat_pipe(void)
 		ret = fd[1];
 		PARA_NOTICE_LOG("stat pipe opened, fd %d\n", ret);
 		add_close_on_fork_list(ret);
+		mark_fd_nonblock(ret);
 	} else
 		clean_exit(EXIT_FAILURE, "failed to open status pipe");
 	return ret;
diff --git a/dccp.c b/dccp.c
index 147e4630..fa48976e 100644
--- a/dccp.c
+++ b/dccp.c
@@ -26,6 +26,7 @@
 #include "para.h"
 #include "error.h"
 #include "dccp.h"
+#include "fd.h"
 
 /** \cond some magic dccp constants */
 #define SOL_DCCP 269
diff --git a/dccp_recv.c b/dccp_recv.c
index 335ad2e6..943b8283 100644
--- a/dccp_recv.c
+++ b/dccp_recv.c
@@ -98,6 +98,7 @@ static int dccp_recv_open(struct receiver_node *rn)
 	ret = -E_DCCP_CONNECT;
 	if (connect(pdd->fd, ai->ai_addr, ai->ai_addrlen) < 0)
 		goto err_out;
+	mark_fd_nonblock(pdd->fd);
 	return 1;
 err_out:
 	dccp_recv_close(rn);
diff --git a/fd.c b/fd.c
index d1e0412d..b9130093 100644
--- a/fd.c
+++ b/fd.c
@@ -100,10 +100,20 @@ int mark_fd_nonblock(int fd)
 */
 void para_fd_set(int fd, fd_set *fds, int *max_fileno)
 {
+
 	if (fd < 0 || fd >= FD_SETSIZE) {
 		PARA_EMERG_LOG("fatal: tried to add invalid fd %d\n", fd);
 		exit(EXIT_FAILURE);
 	}
+#if 0
+	{
+		int flags = fcntl(fd, F_GETFL);
+		if (!(flags & O_NONBLOCK)) {
+			PARA_EMERG_LOG("fd %d is a blocking file descriptor\n", fd);
+			exit(EXIT_FAILURE);
+		}
+	}
+#endif
 	FD_SET(fd, fds);
 	*max_fileno = PARA_MAX(*max_fileno, fd);
 }
diff --git a/http_recv.c b/http_recv.c
index 3d72c7c7..09654167 100644
--- a/http_recv.c
+++ b/http_recv.c
@@ -189,9 +189,10 @@ static int http_recv_open(struct receiver_node *rn)
 	if (!ret < 0)
 		goto err_out;
 	/* get new socket */
-	ret = -E_SOCKET;
-	if ((phd->fd = get_socket()) < 0)
+	ret = get_socket();
+	if (ret < 0)
 		goto err_out;
+	phd->fd = ret;
 	/* init their_addr */
 	init_sockaddr(&their_addr, conf->port_arg, he);
 	/* connect */
@@ -200,6 +201,7 @@ static int http_recv_open(struct receiver_node *rn)
 	ret = para_connect(phd->fd, &their_addr);
 	if (ret < 0)
 		goto err_out;
+	mark_fd_nonblock(phd->fd);
 	phd->status = HTTP_CONNECTED;
 	return 1;
 err_out:
diff --git a/stdin.c b/stdin.c
index cb13250e..8b18c2e2 100644
--- a/stdin.c
+++ b/stdin.c
@@ -105,5 +105,6 @@ void stdin_set_defaults(struct stdin_task *sit)
 	sit->task.post_select = stdin_post_select;
 	sit->task.event_handler = stdin_default_event_handler;
 	sit->task.private_data = sit;
+	mark_fd_nonblock(STDIN_FILENO);
 	sprintf(sit->task.status, "stdin reader");
 }
diff --git a/stdout.c b/stdout.c
index 1c1435a3..2e86fe96 100644
--- a/stdout.c
+++ b/stdout.c
@@ -107,5 +107,6 @@ void stdout_set_defaults(struct stdout_task *sot)
 	sot->task.post_select = stdout_post_select;
 	sot->task.event_handler = stdout_default_event_handler;
 	sot->eof = 0;
+	mark_fd_nonblock(STDOUT_FILENO);
 	sprintf(sot->task.status, "stdout writer");
 }
-- 
2.39.5