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Diffstat (limited to 'm4/ax_have_epoll.m4')
| -rw-r--r-- | m4/ax_have_epoll.m4 | 104 |
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 000000000..9d9bc8736 --- /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 |