projects / lttng-tools.git / blame
| Commit | Line | Data |
|---|---|---|
| 71615260 | 1 | # =========================================================================== |
| 9becf5b7 | 2 | # https://www.gnu.org/software/autoconf-archive/ax_have_epoll.html |
| 71615260 DG |
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@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 | ||
| 9becf5b7 | 45 | #serial 11 |
| 71615260 DG |
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 |