Mercurial > hg > octave-shane > gnulib-hg

view m4/passfd.m4 @ 16869:38e6d30d7e4d

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
poll/select: prevent busy-waiting 2012-05-21 Paolo Bonzini <bonzini@gnu.org> poll/select: prevent busy-waiting. SwitchToThread() only gives away the rest of the current time slice to another thread in the current process. So if the thread that feeds the file decscriptor we're polling is not in the current process, we get busy-waiting. * lib/poll.c: Use SleepEx(1, TRUE) instead of SwitchToThread(). Patch from Theodore Leblond. * lib/select.c: Split polling out of the loop that sets the output fd_sets. Check for zero result and loop if the wait timeout is infinite.
author Paolo Bonzini <bonzini@gnu.org>
date Mon, 21 May 2012 09:52:42 +0200
parents 8250f2777afc
children e542fd46ad6f
line wrap: on
line source

# passfd.m4 serial 8
dnl Copyright (C) 2011-2012 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.

AC_DEFUN([gl_PASSFD],
[
  AC_REQUIRE([gl_HEADER_SYS_SOCKET])
  AC_CHECK_FUNCS_ONCE([recvmsg sendmsg])

  dnl Persuade AIX 5.2 <sys/socket.h> to declare CMSG_SPACE, CMSG_LEN.
  dnl CMSG_FIRSTHDR is POSIX 2008, but CMSG_SPACE is only in RFC 3542.
  AC_DEFINE([_LINUX_SOURCE_COMPAT], [1],
    [Define in order to get some macros on AIX systems.])

  dnl Passfd prefers the POSIX use of msg.msg_control if the CMSG_* macros
  dnl are present, but can fall back to BSD 4.3 style of msg.msg_accrights.
  AC_CHECK_MEMBERS([struct msghdr.msg_accrights], [], [], [[
    #include <sys/types.h>
    #include <sys/socket.h>
  ]])
])