summaryrefslogtreecommitdiff
path: root/m4
diff options
context:
space:
mode:
authorChristian Grothoff <christian@grothoff.org>2018-08-19 11:20:35 +0200
committerChristian Grothoff <christian@grothoff.org>2018-08-19 11:20:35 +0200
commit7fb43dd2aebbbbf2b8547473944ffd1f5d1daa62 (patch)
treead3c4eb5a912d4fecf2bdd09ddf06d40f7402b06 /m4
parent7ba7a46f24cb7db3426ee0349f5dcd0178cf3c29 (diff)
downloadexchange-7fb43dd2aebbbbf2b8547473944ffd1f5d1daa62.tar.gz
exchange-7fb43dd2aebbbbf2b8547473944ffd1f5d1daa62.tar.bz2
exchange-7fb43dd2aebbbbf2b8547473944ffd1f5d1daa62.zip
make fakebank use epoll() on platforms where it is available
Diffstat (limited to 'm4')
-rw-r--r--m4/ax_have_epoll.m4104
1 files changed, 104 insertions, 0 deletions
diff --git a/m4/ax_have_epoll.m4 b/m4/ax_have_epoll.m4
new file mode 100644
index 00000000..9d9bc873
--- /dev/null
+++ b/m4/ax_have_epoll.m4
@@ -0,0 +1,104 @@
+# ===========================================================================
+# https://www.gnu.org/software/autoconf-archive/ax_have_epoll.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+# AX_HAVE_EPOLL([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+# AX_HAVE_EPOLL_PWAIT([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+#
+# DESCRIPTION
+#
+# This macro determines whether the system supports the epoll I/O event
+# interface. A neat usage example would be:
+#
+# AX_HAVE_EPOLL(
+# [AX_CONFIG_FEATURE_ENABLE(epoll)],
+# [AX_CONFIG_FEATURE_DISABLE(epoll)])
+# AX_CONFIG_FEATURE(
+# [epoll], [This platform supports epoll(7)],
+# [HAVE_EPOLL], [This platform supports epoll(7).])
+#
+# The epoll interface was added to the Linux kernel in version 2.5.45, and
+# the macro verifies that a kernel newer than this is installed. This
+# check is somewhat unreliable if <linux/version.h> doesn't match the
+# running kernel, but it is necessary regardless, because glibc comes with
+# stubs for the epoll_create(), epoll_wait(), etc. that allow programs to
+# compile and link even if the kernel is too old; the problem would then
+# be detected only at runtime.
+#
+# Linux kernel version 2.6.19 adds the epoll_pwait() call in addition to
+# epoll_wait(). The availability of that function can be tested with the
+# second macro. Generally speaking, it is safe to assume that
+# AX_HAVE_EPOLL would succeed if AX_HAVE_EPOLL_PWAIT has, but not the
+# other way round.
+#
+# LICENSE
+#
+# Copyright (c) 2008 Peter Simons <simons@cryp.to>
+#
+# Copying and distribution of this file, with or without modification, are
+# permitted in any medium without royalty provided the copyright notice
+# and this notice are preserved. This file is offered as-is, without any
+# warranty.
+
+#serial 11
+
+AC_DEFUN([AX_HAVE_EPOLL], [dnl
+ ax_have_epoll_cppflags="${CPPFLAGS}"
+ AC_CHECK_HEADER([linux/version.h], [CPPFLAGS="${CPPFLAGS} -DHAVE_LINUX_VERSION_H"])
+ AC_MSG_CHECKING([for Linux epoll(7) interface])
+ AC_CACHE_VAL([ax_cv_have_epoll], [dnl
+ AC_LINK_IFELSE([dnl
+ AC_LANG_PROGRAM([dnl
+#include <sys/epoll.h>
+#ifdef HAVE_LINUX_VERSION_H
+# include <linux/version.h>
+# if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,45)
+# error linux kernel version is too old to have epoll
+# endif
+#endif
+], [dnl
+int fd, rc;
+struct epoll_event ev;
+fd = epoll_create(128);
+rc = epoll_wait(fd, &ev, 1, 0);])],
+ [ax_cv_have_epoll=yes],
+ [ax_cv_have_epoll=no])])
+ CPPFLAGS="${ax_have_epoll_cppflags}"
+ AS_IF([test "${ax_cv_have_epoll}" = "yes"],
+ [AC_MSG_RESULT([yes])
+$1],[AC_MSG_RESULT([no])
+$2])
+])dnl
+
+AC_DEFUN([AX_HAVE_EPOLL_PWAIT], [dnl
+ ax_have_epoll_cppflags="${CPPFLAGS}"
+ AC_CHECK_HEADER([linux/version.h],
+ [CPPFLAGS="${CPPFLAGS} -DHAVE_LINUX_VERSION_H"])
+ AC_MSG_CHECKING([for Linux epoll(7) interface with signals extension])
+ AC_CACHE_VAL([ax_cv_have_epoll_pwait], [dnl
+ AC_LINK_IFELSE([dnl
+ AC_LANG_PROGRAM([dnl
+#ifdef HAVE_LINUX_VERSION_H
+# include <linux/version.h>
+# if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
+# error linux kernel version is too old to have epoll_pwait
+# endif
+#endif
+#include <sys/epoll.h>
+#include <signal.h>
+], [dnl
+int fd, rc;
+struct epoll_event ev;
+fd = epoll_create(128);
+rc = epoll_wait(fd, &ev, 1, 0);
+rc = epoll_pwait(fd, &ev, 1, 0, (sigset_t const *)(0));])],
+ [ax_cv_have_epoll_pwait=yes],
+ [ax_cv_have_epoll_pwait=no])])
+ CPPFLAGS="${ax_have_epoll_cppflags}"
+ AS_IF([test "${ax_cv_have_epoll_pwait}" = "yes"],
+ [AC_MSG_RESULT([yes])
+$1],[AC_MSG_RESULT([no])
+$2])
+])dnl