dnl
dnl Copyright (c) 2004-2005 The Trustees of Indiana University and Indiana
dnl                         University Research and Technology
dnl                         Corporation.  All rights reserved.
dnl Copyright (c) 2004-2005 The University of Tennessee and The University
dnl                         of Tennessee Research Foundation.  All rights
dnl                         reserved.
dnl Copyright (c) 2004-2005 High Performance Computing Center Stuttgart, 
dnl                         University of Stuttgart.  All rights reserved.
dnl Copyright (c) 2004-2005 The Regents of the University of California.
dnl                         All rights reserved.
dnl Copyright (c) 2008      Sun Microsystems, Inc.  All rights reserved.
dnl Copyright (c) 2009      Cisco Systems, Inc.  All rights reserved.
dnl $COPYRIGHT$
dnl 
dnl Additional copyrights may follow
dnl 
dnl $HEADER$
dnl

AC_DEFUN([OPAL_SETUP_LIBEVENT],[

dnl OMPI: don't use AC_LIBOBJ
sources=

dnl Check for optional stuff
AC_ARG_WITH(event-rtsig,
  AC_HELP_STRING([--with-event-rtsig],
	         [compile with support for real time signals (experimental)]),
  [usertsig=yes], [usertsig=no])

dnl Checks for libraries.
dnl AC_CHECK_LIB(socket, socket)

dnl Checks for header files.
AC_HEADER_STDC
AC_CHECK_HEADERS(fcntl.h stdarg.h inttypes.h stdint.h poll.h signal.h unistd.h sys/epoll.h sys/time.h sys/queue.h sys/event.h sys/ioctl.h sys/devpoll.h)
if test "x$ac_cv_header_sys_queue_h" = "xyes"; then
	AC_MSG_CHECKING(for TAILQ_FOREACH in sys/queue.h)
	AC_EGREP_CPP(yes,
[
#include <sys/queue.h>
#ifdef TAILQ_FOREACH
 yes
#endif
],	[AC_MSG_RESULT(yes)
	 AC_DEFINE(HAVE_TAILQFOREACH, 1,
		[Define if TAILQ_FOREACH is defined in <sys/queue.h>])],
	AC_MSG_RESULT(no)
	)
fi

if test "x$ac_cv_header_sys_time_h" = "xyes"; then
	AC_MSG_CHECKING(for timeradd in sys/time.h)
	AC_EGREP_CPP(yes,
[
#include <sys/time.h>
#ifdef timeradd
 yes
#endif
],	[ AC_DEFINE(HAVE_TIMERADD, 1,
		[Define if timeradd is defined in <sys/time.h>])
	  AC_MSG_RESULT(yes)] ,AC_MSG_RESULT(no)
)
fi

dnl Checks for typedefs, structures, and compiler characteristics.
AC_HEADER_TIME

dnl Checks for library functions.
AC_CHECK_FUNCS(gettimeofday vasprintf fcntl strtoll)

AC_MSG_CHECKING(for F_SETFD in fcntl.h)
AC_EGREP_CPP(yes,
[
#define _GNU_SOURCE
#include <fcntl.h>
#ifdef F_SETFD
yes
#endif
],      [ AC_DEFINE(HAVE_SETFD, 1,
              [Define if F_SETFD is defined in <fcntl.h>])
          AC_MSG_RESULT(yes) ], AC_MSG_RESULT(no))

needsignal=no
haveselect=no
AC_CHECK_FUNCS(select, [haveselect=yes], )
if test "x$haveselect" = "xyes" ; then
	# OMPI: Don't use AC_LIBOBJ
	sources="select.c $sources"
	needsignal=yes
fi

havepoll=no
havertsig=no
AC_CHECK_FUNCS(poll, [havepoll=yes], )
case "$host" in
    *apple-darwin*)
        haveworkingpoll=0
    ;;
    *)
        if test "$havepoll" = "yes" ; then
	    haveworkingpoll=1
	else
	    haveworkingpoll=0
	fi
    ;;
esac
AC_DEFINE_UNQUOTED([HAVE_WORKING_POLL], [$haveworkingpoll], 
                   [Whether poll works for file descriptors and devices])
if test "x$havepoll" = "xyes" -a "$haveworkingpoll" = "1" ; then
	# OMPI: Don't use AC_LIBOBJ
	sources="poll.c $sources"
	needsignal=yes

	if test "x$usertsig" = "xyes" ; then
		AC_CHECK_FUNCS(sigtimedwait, [havertsig=yes], )
	fi
fi
if test "x$havertsig" = "xyes" ; then
	AC_MSG_CHECKING(for F_SETSIG in fcntl.h)
	AC_EGREP_CPP(yes,
[
#define _GNU_SOURCE
#include <fcntl.h>
#ifdef F_SETSIG
yes
#endif
],	[ AC_MSG_RESULT(yes) ], [ AC_MSG_RESULT(no); havertsig=no])
fi
if test "x$havertsig" = "xyes" ; then
	AC_DEFINE(HAVE_RTSIG, 1, [Define if your system supports POSIX realtime signals])
	# OMPI: Don't use AC_LIBOBJ
	sources="rtsig.c $sources"
	AC_MSG_CHECKING(for working rtsig on pipes)
	AC_TRY_RUN(
[
#define _GNU_SOURCE
#include <fcntl.h>
#include <signal.h>
#include <unistd.h>
#include <stdlib.h>

int sigio()
{
	exit(0);
}

int main()
{
	int fd[2];

	pipe(fd);
	signal(SIGIO, sigio);
	fcntl(fd[0], F_SETOWN, getpid());
	fcntl(fd[0], F_SETSIG, SIGIO);
	fcntl(fd[0], F_SETFL, fcntl(fd[0], F_GETFL) | O_ASYNC);
	write(fd[1], "", 1);
	return 1;
}
],	[ AC_MSG_RESULT(yes)
	  AC_DEFINE(HAVE_WORKING_RTSIG, 1, [Define if realtime signals work on pipes])],
	AC_MSG_RESULT(no))
fi

haveepoll=no
AC_CHECK_FUNCS(epoll_ctl, [haveepoll=yes], )
if test "x$haveepoll" = "xyes" -a "$cross_compiling" != "yes" ; then

        # OMPI: Unfortunately, this test is not sufficient on some
        # Linux distros (e.g., RH 9), where the function is defined
        # and you can link against it, but it's hardwired to return
        # ENOSYS -- and /usr/include/gnu/stubs.h fails to define
        # __stub_epoll_ctl (the usual mechanism in glibc to indicate
        # that a function is a stub and isn't really implemented).
        # Hence, the test succeeds because it thinks it can use
        # epoll_ctl (and friends).  So we have to do a better test
        # after we determine that epoll_ctl is linkable.  Grumble.
        # If we are cross compiling, just trust AC_CHECK_FUNCS

        # OMPI: Unfortunately, this test is not sufficient for another
        # reason.  The event_poll struct is defined in the sys/epoll.h
        # file.  The structure is the interface between the application
        # and the kernel and is therefore compiled into both.  The 
        # event_poll struct is defined with a compiler directive
        # __attribute__ ((__packed__).  It turns out that there is
        # at least one compiler (Sun Studio) that does not currently
        # recognize this directive.  This means that the event_poll
        # struct may be packed in the kernel, but not in the OMPI
        # library.  Badness ensues.  Therefore, check to see that
        # this struct gets correctly passed between OMPI and the
        # kernel.
        
        # In this test we use epoll in Level Triggered mode. We create a pipe
        # and the write only file descriptor of the pipe is added to 
        # the epoll set. The test is successful if epoll_wait() returns 1 
        # indicating that the fd is ready to be written to.

        haveepoll=no
        AC_MSG_CHECKING([for working epoll library interface])
        AC_RUN_IFELSE(AC_LANG_PROGRAM([[
AC_INCLUDES_DEFAULT
#include <sys/epoll.h>]],
[[
    struct epoll_event epevin;
    struct epoll_event epevout;
    int res;
    int epfd;
    int fildes[[2]];

    if ((epfd = epoll_create(1)) == -1)
        exit(1);
    if (pipe(&fildes[[0]]) < 0)
        exit(1);
    memset(&epevin, 0, sizeof(epevin));
    memset(&epevout, 0, sizeof(epevout));
    memset(&epevin.data.ptr, 5, sizeof(epevin.data.ptr));
    epevin.events = EPOLLIN | EPOLLOUT;

    if (epoll_ctl(epfd, EPOLL_CTL_ADD, fildes[[1]], &epevin) == -1)
        exit(1);

    res = epoll_wait(epfd, &epevout, 1, 0);
    if (res != 1) {
        exit(1);
    } else {
        if (epevout.data.ptr != epevin.data.ptr) {
            exit(1);
        }
    }
    /* SUCCESS */
]]),
        [haveepoll=yes
        AC_DEFINE(HAVE_EPOLL, 1,
                 [Define if your system supports the epoll interface])
        # OMPI: Don't use AC_LIBOBJ
        sources="epoll.c $sources"
        needsignal=yes])
        AC_MSG_RESULT([$haveepoll])
fi

haveepollsyscall=no
if test "x$ac_cv_header_sys_epoll_h" = "xyes" -a "x$haveepoll" = "xno" -a "$cross_compiling" != "yes"; then
        # OMPI: See comment above.  This test uses the epoll system call
        # interface instead of the library interface.
        AC_MSG_CHECKING(for working epoll system call)
        AC_RUN_IFELSE(AC_LANG_PROGRAM([[
AC_INCLUDES_DEFAULT
#include <sys/syscall.h>
#include <sys/epoll.h>]],
[[  
    struct epoll_event epevin;
    struct epoll_event epevout;
    int res;
    int epfd;
    int fildes[[2]];

    if ((epfd = syscall(__NR_epoll_create, 1)) == -1)
        exit(1);
    if (pipe(&fildes[[0]]) < 0)
        exit(1);
    memset(&epevin, 0, sizeof(epevin));
    memset(&epevout, 0, sizeof(epevout));
    memset(&epevin.data.ptr, 5, sizeof(epevin.data.ptr));
    epevin.events = EPOLLIN | EPOLLOUT;

    if (syscall(__NR_epoll_ctl, epfd, 
        EPOLL_CTL_ADD, fildes[[1]], &epevin) == -1)
        exit(1);

    res = syscall(__NR_epoll_wait, epfd, &epevout, 1, 0);
    if (res != 1) {
        exit(1);
    } else {
        if (epevout.data.ptr != epevin.data.ptr) {
            exit(1);
        }
    }
    /* SUCCESS */
]]),
        [haveepollsyscall=yes
        AC_DEFINE(HAVE_EPOLL, 1,
                 [Define if your system supports the epoll interface])
        # OMPI: don't use AC_LIBOBJ
        sources="epoll_sub.c epoll.c $sources"
        needsignal=yes])
        AC_MSG_RESULT([$haveepollsyscall])
fi

havedevpoll=no
if test "x$ac_cv_header_sys_devpoll_h" = "xyes"; then
        AC_DEFINE(HAVE_DEVPOLL, 1,
                    [Define if /dev/poll is available])
        # OMPI: Don't use AC_LIBOBJ(devpoll)
        sources="devpoll.c $sources"
        needsignal=yes
fi

havekqueue=no
if test "x$ac_cv_header_sys_event_h" = "xyes"; then
    # All versions of MAC OS X before at least 10.5.2 are
    # completely broken when kqueue is used with pty. So, until
    # they get fixed, completely disable kqueue on MAC OS X.
    case "$host" in
        *apple-darwin*)
		    AC_MSG_CHECKING(for working kqueue)
            havekqueue="no"
            AC_MSG_RESULT([no (MAC OS X)])
        ;;
        *)
            AC_CHECK_FUNCS(kqueue, [havekqueue=yes], )
        ;;
    esac
	if test "x$havekqueue" = "xyes" ; then
		AC_MSG_CHECKING(for working kqueue)
		AC_TRY_RUN(
#include <sys/types.h>
#include <sys/time.h>
#include <sys/event.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>

int
main()
{
	int kq;
	int n;
	int fd[[2]];
	struct kevent ev;
	struct timespec ts;
	char buf[[8000]];

	if (pipe(fd) == -1)
		exit(1);
	if (fcntl(fd[[1]], F_SETFL, O_NONBLOCK) == -1)
		exit(1);

	while ((n = write(fd[[1]], buf, sizeof(buf))) == sizeof(buf))
		;

        if ((kq = kqueue()) == -1)
		exit(1);

	ev.ident = fd[[1]];
	ev.filter = EVFILT_WRITE;
	ev.flags = EV_ADD | EV_ENABLE;
	n = kevent(kq, &ev, 1, NULL, 0, NULL);
	if (n == -1)
		exit(1);
	
	read(fd[[0]], buf, sizeof(buf));

	ts.tv_sec = 0;
	ts.tv_nsec = 0;
	n = kevent(kq, NULL, 0, &ev, 1, &ts);
	if (n == -1 || n == 0)
		exit(1);

	exit(0);
}, [AC_MSG_RESULT(yes)
    AC_DEFINE(HAVE_WORKING_KQUEUE, 1,
		[Define if kqueue works correctly with pipes])
    sources="kqueue.c $sources"], AC_MSG_RESULT(no), AC_MSG_RESULT(no))
    # OMPI: don't use AC_LIBOBJ
	fi
fi

haveeventports=no
AC_CHECK_FUNCS(port_create, [haveeventports=yes], )
# JMS Per #1273, Solaris event ports are temporarily disabled.
haveeventports=no
if test "x$haveeventports" = "xyes" ; then
    AC_DEFINE(HAVE_EVENT_PORTS, 1,
        [Define if your system supports event ports])
    sources="evport.c $sources"
    needsignal=yes
fi

if test "x$needsignal" = "xyes" ; then
    # OMPI: don't use AC_LIBOBJ
    sources="signal.c $sources"
fi

# OMPI: AC_REPLACE_FUNCS doesn't have much meaning here because it
# uses AC_LIBOBJ; use our own test
#AC_REPLACE_FUNCS(err)

AC_TYPE_PID_T
AC_TYPE_SIZE_T
AC_CHECK_TYPE(u_int64_t, unsigned long long)
AC_CHECK_TYPE(u_int32_t, unsigned int)
AC_CHECK_TYPE(u_int16_t, unsigned short)
AC_CHECK_TYPE(u_int8_t, unsigned char)


# OMPI: Save the libobj sources
OPAL_LIBEVENT_SOURCES="$sources"
AC_SUBST(OPAL_LIBEVENT_SOURCES)

# OMPI: All done
unset sources])dnl