Close #19827: On UNIX, setblocking() and settimeout() methods of socket.socket
can now avoid a second syscall if the ioctl() function can be used, or if the
non-blocking flag of the socket is unchanged.
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index 9e0da13..1444369 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -585,8 +585,9 @@
static int
internal_setblocking(PySocketSockObject *s, int block)
{
-#ifndef MS_WINDOWS
- int delay_flag;
+#if !defined(MS_WINDOWS) \
+ && !((defined(HAVE_SYS_IOCTL_H) && defined(FIONBIO)) || defined(__VMS))
+ int delay_flag, new_delay_flag;
#endif
#ifdef SOCK_NONBLOCK
if (block)
@@ -597,17 +598,18 @@
Py_BEGIN_ALLOW_THREADS
#ifndef MS_WINDOWS
-#if defined(__VMS)
+#if (defined(HAVE_SYS_IOCTL_H) && defined(FIONBIO)) || defined(__VMS)
block = !block;
ioctl(s->sock_fd, FIONBIO, (unsigned int *)&block);
-#else /* !__VMS */
+#else
delay_flag = fcntl(s->sock_fd, F_GETFL, 0);
if (block)
- delay_flag &= (~O_NONBLOCK);
+ new_delay_flag = delay_flag & (~O_NONBLOCK);
else
- delay_flag |= O_NONBLOCK;
- fcntl(s->sock_fd, F_SETFL, delay_flag);
-#endif /* !__VMS */
+ new_delay_flag = delay_flag | O_NONBLOCK;
+ if (new_delay_flag != delay_flag)
+ fcntl(s->sock_fd, F_SETFL, new_delay_flag);
+#endif
#else /* MS_WINDOWS */
block = !block;
ioctlsocket(s->sock_fd, FIONBIO, (u_long*)&block);