Attachment #68605: epoll patch for bug #106208

/* Define if you have the <linux/epoll.h> header file. */

#undef HAVE_LINUX_EPOLL_H

/* Define if you have the <linux/epoll.h> header file. */

#undef HAVE_LINUX_EPOLL_H

if test "${ac_cv_header_sys_epoll_h+set}" = set; then

  echo "$as_me:$LINENO: checking for sys/epoll.h" >&5

echo $ECHO_N "checking for sys/epoll.h... $ECHO_C" >&6

if test "${ac_cv_header_sys_epoll_h+set}" = set; then

  echo $ECHO_N "(cached) $ECHO_C" >&6

fi

echo "$as_me:$LINENO: result: $ac_cv_header_sys_epoll_h" >&5

echo "${ECHO_T}$ac_cv_header_sys_epoll_h" >&6

else

  # Is the header compilable?

echo "$as_me:$LINENO: checking sys/epoll.h usability" >&5

echo $ECHO_N "checking sys/epoll.h usability... $ECHO_C" >&6

cat >conftest.$ac_ext <<_ACEOF

/* confdefs.h.  */

_ACEOF

cat confdefs.h >>conftest.$ac_ext

cat >>conftest.$ac_ext <<_ACEOF

/* end confdefs.h.  */

$ac_includes_default

#include <sys/epoll.h>

_ACEOF

rm -f conftest.$ac_objext

if { (eval echo "$as_me:$LINENO: \"$ac_compile\"") >&5

  (eval $ac_compile) 2>conftest.er1

  ac_status=$?

  grep -v '^ *+' conftest.er1 >conftest.err

  rm -f conftest.er1

  cat conftest.err >&5

  echo "$as_me:$LINENO: \$? = $ac_status" >&5

  (exit $ac_status); } &&

	 { ac_try='test -z "$ac_c_werror_flag"

			 || test ! -s conftest.err'

  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5

  (eval $ac_try) 2>&5

  ac_status=$?

  echo "$as_me:$LINENO: \$? = $ac_status" >&5

  (exit $ac_status); }; } &&

	 { ac_try='test -s conftest.$ac_objext'

  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5

  (eval $ac_try) 2>&5

  ac_status=$?

  echo "$as_me:$LINENO: \$? = $ac_status" >&5

  (exit $ac_status); }; }; then

  ac_header_compiler=yes

else

  echo "$as_me: failed program was:" >&5

sed 's/^/| /' conftest.$ac_ext >&5

ac_header_compiler=no

fi

rm -f conftest.err conftest.$ac_objext conftest.$ac_ext

echo "$as_me:$LINENO: result: $ac_header_compiler" >&5

echo "${ECHO_T}$ac_header_compiler" >&6

# Is the header present?

echo "$as_me:$LINENO: checking sys/epoll.h presence" >&5

echo $ECHO_N "checking sys/epoll.h presence... $ECHO_C" >&6

cat >conftest.$ac_ext <<_ACEOF

/* confdefs.h.  */

_ACEOF

cat confdefs.h >>conftest.$ac_ext

cat >>conftest.$ac_ext <<_ACEOF

/* end confdefs.h.  */

#include <sys/epoll.h>

_ACEOF

if { (eval echo "$as_me:$LINENO: \"$ac_cpp conftest.$ac_ext\"") >&5

  (eval $ac_cpp conftest.$ac_ext) 2>conftest.er1

  ac_status=$?

  grep -v '^ *+' conftest.er1 >conftest.err

  rm -f conftest.er1

  cat conftest.err >&5

  echo "$as_me:$LINENO: \$? = $ac_status" >&5

  (exit $ac_status); } >/dev/null; then

  if test -s conftest.err; then

    ac_cpp_err=$ac_c_preproc_warn_flag

    ac_cpp_err=$ac_cpp_err$ac_c_werror_flag

  else

    ac_cpp_err=

  fi

else

  ac_cpp_err=yes

fi

if test -z "$ac_cpp_err"; then

  ac_header_preproc=yes

else

  echo "$as_me: failed program was:" >&5

sed 's/^/| /' conftest.$ac_ext >&5

  ac_header_preproc=no

fi

rm -f conftest.err conftest.$ac_ext

echo "$as_me:$LINENO: result: $ac_header_preproc" >&5

echo "${ECHO_T}$ac_header_preproc" >&6

# So?  What about this header?

case $ac_header_compiler:$ac_header_preproc:$ac_c_preproc_warn_flag in

  yes:no: )

    { echo "$as_me:$LINENO: WARNING: sys/epoll.h: accepted by the compiler, rejected by the preprocessor!" >&5

echo "$as_me: WARNING: sys/epoll.h: accepted by the compiler, rejected by the preprocessor!" >&2;}

    { echo "$as_me:$LINENO: WARNING: sys/epoll.h: proceeding with the compiler's result" >&5

echo "$as_me: WARNING: sys/epoll.h: proceeding with the compiler's result" >&2;}

    ac_header_preproc=yes

    ;;

  no:yes:* )

    { echo "$as_me:$LINENO: WARNING: sys/epoll.h: present but cannot be compiled" >&5

echo "$as_me: WARNING: sys/epoll.h: present but cannot be compiled" >&2;}

    { echo "$as_me:$LINENO: WARNING: sys/epoll.h:     check for missing prerequisite headers?" >&5

echo "$as_me: WARNING: sys/epoll.h:     check for missing prerequisite headers?" >&2;}

    { echo "$as_me:$LINENO: WARNING: sys/epoll.h: see the Autoconf documentation" >&5

echo "$as_me: WARNING: sys/epoll.h: see the Autoconf documentation" >&2;}

    { echo "$as_me:$LINENO: WARNING: sys/epoll.h:     section \"Present But Cannot Be Compiled\"" >&5

echo "$as_me: WARNING: sys/epoll.h:     section \"Present But Cannot Be Compiled\"" >&2;}

    { echo "$as_me:$LINENO: WARNING: sys/epoll.h: proceeding with the preprocessor's result" >&5

echo "$as_me: WARNING: sys/epoll.h: proceeding with the preprocessor's result" >&2;}

    { echo "$as_me:$LINENO: WARNING: sys/epoll.h: in the future, the compiler will take precedence" >&5

echo "$as_me: WARNING: sys/epoll.h: in the future, the compiler will take precedence" >&2;}

    (

      cat <<\_ASBOX

## ------------------------------------------ ##

## Report this to the AC_PACKAGE_NAME lists.  ##

## ------------------------------------------ ##

_ASBOX

    ) |

      sed "s/^/$as_me: WARNING:     /" >&2

    ;;

esac

echo "$as_me:$LINENO: checking for sys/epoll.h" >&5

echo $ECHO_N "checking for sys/epoll.h... $ECHO_C" >&6

if test "${ac_cv_header_sys_epoll_h+set}" = set; then

  echo $ECHO_N "(cached) $ECHO_C" >&6

else

  ac_cv_header_sys_epoll_h=$ac_header_preproc

fi

echo "$as_me:$LINENO: result: $ac_cv_header_sys_epoll_h" >&5

echo "${ECHO_T}$ac_cv_header_sys_epoll_h" >&6

fi

if test $ac_cv_header_sys_epoll_h = yes; then

  cat >>confdefs.h <<\_ACEOF

#define HAVE_LINUX_EPOLL_H 1

_ACEOF

fi

AC_CHECK_HEADER(sys/epoll.h, AC_DEFINE(HAVE_LINUX_EPOLL_H))

#    ifdef HAVE_LINUX_EPOLL_H /* Too minimize code changes, we pretend we have HAVE_LINUX_KPOLL_H as well */

#      define HAVE_LINUX_KPOLL_H 1

#    endif

#ifdef HAVE_LINUX_EPOLL_H

static struct epoll_event* dev_epoll_map;

/* XXX Implement correct mapping from POLLIN/POLLOUT to/from EPOLLIN/EPOLLOUT */

/* Currenltly POLLIN/POLLOUT == EPOLLIN/EPOLLOUT. So these macros will work */

#define EPOLL_TO_POLL(bit_map) (bit_map)

#define POLL_TO_EPOLL(bit_map) (bit_map & (EPOLLIN|EPOLLOUT))

#else

#endif /* HAVE_LINUX_KPOLL_H */

#ifdef HAVE_LINUX_EPOLL_H

	if ( do_event_poll ) {

           if ((r = epoll_wait(dev_poll_fd,dev_epoll_map,max_fd_plus_one,0)) > 0) {

	    for (i = 0; (i < r); i++) {

	      short revents = dev_epoll_map[i].events;

	      if (revents != 0) {

	        int fd = dev_epoll_map[i].data.fd;

		rp->pfd.fd = fd;

		rp->pfd.events = poll_fds[fd_data[fd].pix].events;

		rp->pfd.revents = EPOLL_TO_POLL(revents);

		rp->iport = fd_data[fd].inport;

		rp->oport = fd_data[fd].outport;

		rp++;

	        nof_ready_fds ++;

	      } 

	    }

           }

        }

#else

#endif /*HAVE_LINUX_EPOLL_H */

#ifdef HAVE_LINUX_EPOLL_H

static void epoll_init()

{

    /* max_files is just a hint to the kernel */

    if ( (dev_poll_fd=epoll_create(max_files)) < 0 ) {

        DEBUGF(("Will use poll()\n"));

        dev_poll_fd = -1; /* We will not use ekpoll */

    } else {

        DEBUGF(("Will use epoll\n"));

        dev_epoll_map = (struct epoll_event *) erts_alloc(ERTS_ALC_T_POLL_FDS, (sizeof(struct epoll_event) * max_files));

	erts_sys_misc_mem_sz += sizeof(struct epoll_event) * max_files;

    }

}

#else

#endif /* HAVE_LINUX_EPOLL_H */

#ifdef HAVE_LINUX_EPOLL_H

        epoll_init();

#else

#endif

#ifdef HAVE_LINUX_EPOLL_H

       int events = poll_fds[pix].events;

       int fd = poll_fds[pix].fd;

       if (old_events && events & POLLREMOVE) {

            /* Delete file descriptor from epoll list */

            res = epoll_ctl(dev_poll_fd,EPOLL_CTL_DEL,fd,NULL);

            /* XXX check return code */

       } else {

            struct epoll_event epoll_ctl_event;

            epoll_ctl_event.data.fd = fd;

            epoll_ctl_event.events = POLL_TO_EPOLL(events);

            if (old_events) {

                /* Modify exiting fd */

                res = epoll_ctl(dev_poll_fd,EPOLL_CTL_MOD,fd,&epoll_ctl_event);

                /* XXX check return code */

            } else {

                /* Add fd to epoll list */

                res = epoll_ctl(dev_poll_fd,EPOLL_CTL_ADD,fd,&epoll_ctl_event);

                /* XXX check return code */

            } 

       }

#else

#endif /* HAVE_LINUX_EPOLL_H */