William Ahern:

  Make UDP sockets non-blocking. I've confirmed that at least on Linux 2.4 a
  read event can come back from poll() on a valid SOCK_DGRAM socket but
  recv(2) will still block. This patch doesn't ignore EAGAIN in
  read_udp_packets(), though maybe it should. (This patch was edited by Daniel
  Stenberg and a new configure test was added (imported from curl's configure)
  to properly detect what non-blocking socket approach to use.)

1 files changed, 123 insertions, 0 deletions

diff --git a/ares/acinclude.m4 b/ares/acinclude.m4
index 1b197f0a0..2f6256ae4 100644
--- a/ares/acinclude.m4
+++ b/ares/acinclude.m4
@@ -1,3 +1,126 @@
+dnl Check for how to set a socket to non-blocking state. There seems to exist

+dnl four known different ways, with the one used almost everywhere being POSIX

+dnl and XPG3, while the other different ways for different systems (old BSD,

+dnl Windows and Amiga).

+dnl

+dnl There are two known platforms (AIX 3.x and SunOS 4.1.x) where the

+dnl O_NONBLOCK define is found but does not work. This condition is attempted

+dnl to get caught in this script by using an excessive number of #ifdefs...

+dnl

+AC_DEFUN([CURL_CHECK_NONBLOCKING_SOCKET],

+[

+  AC_MSG_CHECKING([non-blocking sockets style])

+

+  AC_TRY_COMPILE([

+/* headers for O_NONBLOCK test */

+#include <sys/types.h>

+#include <unistd.h>

+#include <fcntl.h>

+],[

+/* try to compile O_NONBLOCK */

+

+#if defined(sun) || defined(__sun__) || defined(__SUNPRO_C) || defined(__SUNPRO_CC)

+# if defined(__SVR4) || defined(__srv4__)

+#  define PLATFORM_SOLARIS

+# else

+#  define PLATFORM_SUNOS4

+# endif

+#endif

+#if (defined(_AIX) || defined(__xlC__)) && !defined(_AIX4)

+# define PLATFORM_AIX_V3

+#endif

+

+#if defined(PLATFORM_SUNOS4) || defined(PLATFORM_AIX_V3) || defined(__BEOS__)

+#error "O_NONBLOCK does not work on this platform"

+#endif

+  int socket;

+  int flags = fcntl(socket, F_SETFL, flags | O_NONBLOCK);

+],[

+dnl the O_NONBLOCK test was fine

+nonblock="O_NONBLOCK"

+AC_DEFINE(HAVE_O_NONBLOCK, 1, [use O_NONBLOCK for non-blocking sockets])

+],[

+dnl the code was bad, try a different program now, test 2

+

+  AC_TRY_COMPILE([

+/* headers for FIONBIO test */

+#include <unistd.h>

+#include <stropts.h>

+],[

+/* FIONBIO source test (old-style unix) */

+ int socket;

+ int flags = ioctl(socket, FIONBIO, &flags);

+],[

+dnl FIONBIO test was good

+nonblock="FIONBIO"

+AC_DEFINE(HAVE_FIONBIO, 1, [use FIONBIO for non-blocking sockets])

+],[

+dnl FIONBIO test was also bad

+dnl the code was bad, try a different program now, test 3

+

+  AC_TRY_COMPILE([

+/* headers for ioctlsocket test (cygwin?) */

+#include <windows.h>

+],[

+/* ioctlsocket source code */

+ int socket;

+ unsigned long flags = ioctlsocket(socket, FIONBIO, &flags);

+],[

+dnl ioctlsocket test was good

+nonblock="ioctlsocket"

+AC_DEFINE(HAVE_IOCTLSOCKET, 1, [use ioctlsocket() for non-blocking sockets])

+],[

+dnl ioctlsocket didnt compile!, go to test 4

+

+  AC_TRY_LINK([

+/* headers for IoctlSocket test (Amiga?) */

+#include <sys/ioctl.h>

+],[

+/* IoctlSocket source code */

+ int socket;

+ int flags = IoctlSocket(socket, FIONBIO, (long)1);

+],[

+dnl ioctlsocket test was good

+nonblock="IoctlSocket"

+AC_DEFINE(HAVE_IOCTLSOCKET_CASE, 1, [use Ioctlsocket() for non-blocking sockets])

+],[

+dnl Ioctlsocket didnt compile, do test 5!

+  AC_TRY_COMPILE([

+/* headers for SO_NONBLOCK test (BeOS) */

+#include <socket.h>

+],[

+/* SO_NONBLOCK source code */

+ long b = 1;

+ int socket;

+ int flags = setsockopt(socket, SOL_SOCKET, SO_NONBLOCK, &b, sizeof(b));

+],[

+dnl the SO_NONBLOCK test was good

+nonblock="SO_NONBLOCK"

+AC_DEFINE(HAVE_SO_NONBLOCK, 1, [use SO_NONBLOCK for non-blocking sockets])

+],[

+dnl test 5 didnt compile!

+nonblock="nada"

+AC_DEFINE(HAVE_DISABLED_NONBLOCKING, 1, [disabled non-blocking sockets])

+])

+dnl end of fifth test

+

+])

+dnl end of forth test

+

+])

+dnl end of third test

+

+])

+dnl end of second test

+

+])

+dnl end of non-blocking try-compile test

+  AC_MSG_RESULT($nonblock)

+

+  if test "$nonblock" = "nada"; then

+    AC_MSG_WARN([non-block sockets disabled])

+  fi

+])

 

 dnl We create a function for detecting which compiler we use and then set as

 dnl pendantic compiler options as possible for that particular compiler. The