1 # =========================================================================== 2 # http://www.gnu.org/software/autoconf-archive/ax_have_epoll.html 3 # =========================================================================== 4 # 5 # SYNOPSIS 6 # 7 # AX_HAVE_EPOLL([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND]) 8 # AX_HAVE_EPOLL_PWAIT([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND]) 9 # 10 # DESCRIPTION 11 # 12 # This macro determines whether the system supports the epoll I/O event 13 # interface. A neat usage example would be: 14 # 15 # AX_HAVE_EPOLL( 16 # [AX_CONFIG_FEATURE_ENABLE(epoll)], 17 # [AX_CONFIG_FEATURE_DISABLE(epoll)]) 18 # AX_CONFIG_FEATURE( 19 # [epoll], [This platform supports epoll(7)], 20 # [HAVE_EPOLL], [This platform supports epoll(7).]) 21 # 22 # The epoll interface was added to the Linux kernel in version 2.5.45, and 23 # the macro verifies that a kernel newer than this is installed. This 24 # check is somewhat unreliable if <linux/version.h> doesn't match the 25 # running kernel, but it is necessary regardless, because glibc comes with 26 # stubs for the epoll_create(), epoll_wait(), etc. that allow programs to 27 # compile and link even if the kernel is too old; the problem would then 28 # be detected only at runtime. 29 # 30 # Linux kernel version 2.6.19 adds the epoll_pwait() call in addition to 31 # epoll_wait(). The availability of that function can be tested with the 32 # second macro. Generally speaking, it is safe to assume that 33 # AX_HAVE_EPOLL would succeed if AX_HAVE_EPOLL_PWAIT has, but not the 34 # other way round. 35 # 36 # LICENSE 37 # 38 # Copyright (c) 2008 Peter Simons <simons (a] cryp.to> 39 # 40 # Copying and distribution of this file, with or without modification, are 41 # permitted in any medium without royalty provided the copyright notice 42 # and this notice are preserved. This file is offered as-is, without any 43 # warranty. 44 45 #serial 10 46 47 AC_DEFUN([AX_HAVE_EPOLL], [dnl 48 ax_have_epoll_cppflags="${CPPFLAGS}" 49 AC_CHECK_HEADER([linux/version.h], [CPPFLAGS="${CPPFLAGS} -DHAVE_LINUX_VERSION_H"]) 50 AC_MSG_CHECKING([for Linux epoll(7) interface]) 51 AC_CACHE_VAL([ax_cv_have_epoll], [dnl 52 AC_LINK_IFELSE([dnl 53 AC_LANG_PROGRAM([dnl 54 #include <sys/epoll.h> 55 #ifdef HAVE_LINUX_VERSION_H 56 # include <linux/version.h> 57 # if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,45) 58 # error linux kernel version is too old to have epoll 59 # endif 60 #endif 61 ], [dnl 62 int fd, rc; 63 struct epoll_event ev; 64 fd = epoll_create(128); 65 rc = epoll_wait(fd, &ev, 1, 0);])], 66 [ax_cv_have_epoll=yes], 67 [ax_cv_have_epoll=no])]) 68 CPPFLAGS="${ax_have_epoll_cppflags}" 69 AS_IF([test "${ax_cv_have_epoll}" = "yes"], 70 [AC_MSG_RESULT([yes]) 71 $1],[AC_MSG_RESULT([no]) 72 $2]) 73 ])dnl 74 75 AC_DEFUN([AX_HAVE_EPOLL_PWAIT], [dnl 76 ax_have_epoll_cppflags="${CPPFLAGS}" 77 AC_CHECK_HEADER([linux/version.h], 78 [CPPFLAGS="${CPPFLAGS} -DHAVE_LINUX_VERSION_H"]) 79 AC_MSG_CHECKING([for Linux epoll(7) interface with signals extension]) 80 AC_CACHE_VAL([ax_cv_have_epoll_pwait], [dnl 81 AC_LINK_IFELSE([dnl 82 AC_LANG_PROGRAM([dnl 83 #ifdef HAVE_LINUX_VERSION_H 84 # include <linux/version.h> 85 # if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19) 86 # error linux kernel version is too old to have epoll_pwait 87 # endif 88 #endif 89 #include <sys/epoll.h> 90 #include <signal.h> 91 ], [dnl 92 int fd, rc; 93 struct epoll_event ev; 94 fd = epoll_create(128); 95 rc = epoll_wait(fd, &ev, 1, 0); 96 rc = epoll_pwait(fd, &ev, 1, 0, (sigset_t const *)(0));])], 97 [ax_cv_have_epoll_pwait=yes], 98 [ax_cv_have_epoll_pwait=no])]) 99 CPPFLAGS="${ax_have_epoll_cppflags}" 100 AS_IF([test "${ax_cv_have_epoll_pwait}" = "yes"], 101 [AC_MSG_RESULT([yes]) 102 $1],[AC_MSG_RESULT([no]) 103 $2]) 104 ])dnl 105
