|
| 1 | +dnl This is based on an old macro from the GNU Autoconf Macro Archive at: |
| 2 | +dnl http://www.gnu.org/software/ac-archive/htmldoc/acx_pthread.html |
| 3 | +dnl but it's been rather heavily hacked --- beware of blindly dropping in |
| 4 | +dnl upstream changes! |
| 5 | +dnl |
| 6 | +AC_DEFUN([ACX_PTHREAD],[ |
| 7 | +AC_REQUIRE([AC_CANONICAL_HOST]) |
| 8 | +AC_LANG_SAVE |
| 9 | +AC_LANG_C |
| 10 | +acx_pthread_ok=no |
| 11 | +
|
| 12 | +# We used to check for pthread.h first, but this fails if pthread.h |
| 13 | +# requires special compiler flags (e.g. on True64 or Sequent). |
| 14 | +# It gets checked for in the link test anyway. |
| 15 | +
|
| 16 | +# First of all, check if the user has set any of the PTHREAD_LIBS, |
| 17 | +# etcetera environment variables, and if threads linking works using |
| 18 | +# them: |
| 19 | +if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then |
| 20 | + save_CFLAGS="$CFLAGS" |
| 21 | + CFLAGS="$CFLAGS $PTHREAD_CFLAGS" |
| 22 | + save_LIBS="$LIBS" |
| 23 | + LIBS="$PTHREAD_LIBS $LIBS" |
| 24 | +AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS]) |
| 25 | +AC_TRY_LINK_FUNC(pthread_join,acx_pthread_ok=yes) |
| 26 | +AC_MSG_RESULT($acx_pthread_ok) |
| 27 | + if test x"$acx_pthread_ok" = xno; then |
| 28 | + PTHREAD_LIBS="" |
| 29 | + PTHREAD_CFLAGS="" |
| 30 | + fi |
| 31 | + LIBS="$save_LIBS" |
| 32 | + CFLAGS="$save_CFLAGS" |
| 33 | +fi |
| 34 | +
|
| 35 | +# We must check for the threads library under a number of different |
| 36 | +# names; the ordering is very important because some systems |
| 37 | +# (e.g. DEC) have both -lpthread and -lpthreads, where one of the |
| 38 | +# libraries is broken (non-POSIX). |
| 39 | +
|
| 40 | +# Create a list of thread flags to try. Items starting with a "-" are |
| 41 | +# C compiler flags, and other items are library names, except for "none" |
| 42 | +# which indicates that we try without any flags at all, and "pthread-config" |
| 43 | +# which is a program returning the flags for the Pth emulation library. |
| 44 | +
|
| 45 | +acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config pthreadGC2" |
| 46 | +
|
| 47 | +# The ordering *is* (sometimes) important. Some notes on the |
| 48 | +# individual items follow: |
| 49 | +
|
| 50 | +# pthreads: AIX (must check this before -lpthread) |
| 51 | +# none: in case threads are in libc; should be tried before -Kthread and |
| 52 | +# other compiler flags to prevent continual compiler warnings |
| 53 | +# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h) |
| 54 | +# -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able) |
| 55 | +# lthread: LinuxThreads port on FreeBSD (also preferred to -pthread) |
| 56 | +# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads) |
| 57 | +# -pthreads: Solaris/gcc |
| 58 | +# -mthreads: Mingw32/gcc, Lynx/gcc |
| 59 | +# -mt: Sun Workshop C (may only link SunOS threads[-lthread], but it |
| 60 | +# doesn't hurt to check since this sometimes defines pthreads too; |
| 61 | +# also defines -D_REENTRANT) |
| 62 | +# pthread: Linux, etcetera |
| 63 | +# --thread-safe: KAI C++ |
| 64 | +# pthread-config: use pthread-config program (for GNU Pth library) |
| 65 | +
|
| 66 | +case "${host_cpu}-${host_os}" in |
| 67 | + *solaris*) |
| 68 | +
|
| 69 | + # On Solaris (at least, for some versions), libc contains stubbed |
| 70 | + # (non-functional) versions of the pthreads routines, so link-based |
| 71 | + # tests will erroneously succeed. (We need to link with -pthread or |
| 72 | + # -lpthread.) (The stubs are missing pthread_cleanup_push, or rather |
| 73 | + # a function called by this macro, so we could check for that, but |
| 74 | + # who knows whether they'll stub that too in a future libc.) So, |
| 75 | + # we'll just look for -pthreads and -lpthread first: |
| 76 | +
|
| 77 | + acx_pthread_flags="-pthread -pthreads pthread -mt $acx_pthread_flags" |
| 78 | + ;; |
| 79 | +esac |
| 80 | +
|
| 81 | +if test x"$acx_pthread_ok" = xno; then |
| 82 | +for flag in $acx_pthread_flags; do |
| 83 | +
|
| 84 | + tryPTHREAD_CFLAGS="" |
| 85 | + tryPTHREAD_LIBS="" |
| 86 | + case $flag in |
| 87 | + none) |
| 88 | +AC_MSG_CHECKING([whether pthreads work without any flags]) |
| 89 | + ;; |
| 90 | +
|
| 91 | + -*) |
| 92 | +AC_MSG_CHECKING([whether pthreads work with $flag]) |
| 93 | + tryPTHREAD_CFLAGS="$flag" |
| 94 | + ;; |
| 95 | +
|
| 96 | + pthread-config) |
| 97 | + # skip this if we already have flags defined, for PostgreSQL |
| 98 | + if test x"$PTHREAD_CFLAGS" != x -o x"$PTHREAD_LIBS" != x; then continue; fi |
| 99 | +AC_CHECK_PROG(acx_pthread_config,pthread-config,yes,no) |
| 100 | + if test x"$acx_pthread_config" = xno; then continue; fi |
| 101 | + tryPTHREAD_CFLAGS="`pthread-config --cflags`" |
| 102 | + tryPTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`" |
| 103 | + ;; |
| 104 | +
|
| 105 | + *) |
| 106 | +AC_MSG_CHECKING([for the pthreads library -l$flag]) |
| 107 | + tryPTHREAD_LIBS="-l$flag" |
| 108 | + ;; |
| 109 | + esac |
| 110 | +
|
| 111 | + save_LIBS="$LIBS" |
| 112 | + save_CFLAGS="$CFLAGS" |
| 113 | + LIBS="$tryPTHREAD_LIBS $PTHREAD_LIBS $LIBS" |
| 114 | + CFLAGS="$CFLAGS $PTHREAD_CFLAGS $tryPTHREAD_CFLAGS" |
| 115 | +
|
| 116 | + # Check for various functions. We must include pthread.h, |
| 117 | + # since some functions may be macros. (On the Sequent, we |
| 118 | + # need a special flag -Kthread to make this header compile.) |
| 119 | + # We check for pthread_join because it is in -lpthread on IRIX |
| 120 | + # while pthread_create is in libc. We check for pthread_attr_init |
| 121 | + # due to DEC craziness with -lpthreads. We check for |
| 122 | + # pthread_cleanup_push because it is one of the few pthread |
| 123 | + # functions on Solaris that doesn't have a non-functional libc stub. |
| 124 | + # We try pthread_create on general principles. |
| 125 | +AC_TRY_LINK([#include <pthread.h>], |
| 126 | +[pthread_t th; pthread_join(th, 0); |
| 127 | + pthread_attr_init(0); pthread_cleanup_push(0, 0); |
| 128 | + pthread_create(0,0,0,0); pthread_cleanup_pop(0);], |
| 129 | +[acx_pthread_ok=yes],[acx_pthread_ok=no]) |
| 130 | +
|
| 131 | + if test "x$acx_pthread_ok" = xyes; then |
| 132 | + # Don't use options that are ignored by the compiler. |
| 133 | + # We find them by checking stderror. |
| 134 | + cat >conftest.$ac_ext <<_ACEOF |
| 135 | +int |
| 136 | +main (int argc, char **argv) |
| 137 | +{ |
| 138 | + (void) argc; |
| 139 | + (void) argv; |
| 140 | + return 0; |
| 141 | +} |
| 142 | +_ACEOF |
| 143 | + rm -f conftest.$ac_objext conftest$ac_exeext |
| 144 | + # Check both linking and compiling, because they might tolerate different options. |
| 145 | + if test "`(eval $ac_link 2>&1 1>&5)`" = "" && test "`(eval $ac_compile 2>&1 1>&5)`" = ""; then |
| 146 | + # The original macro breaks out of the loop at this point, |
| 147 | + # but we continue trying flags because Linux needs -lpthread |
| 148 | + # too to build libpq successfully. The test above only |
| 149 | + # tests for building binaries, not shared libraries. |
| 150 | + PTHREAD_LIBS=" $tryPTHREAD_LIBS $PTHREAD_LIBS" |
| 151 | + PTHREAD_CFLAGS="$PTHREAD_CFLAGS $tryPTHREAD_CFLAGS" |
| 152 | + else acx_pthread_ok=no |
| 153 | + fi |
| 154 | + fi |
| 155 | +
|
| 156 | + LIBS="$save_LIBS" |
| 157 | + CFLAGS="$save_CFLAGS" |
| 158 | +
|
| 159 | +AC_MSG_RESULT($acx_pthread_ok) |
| 160 | +done |
| 161 | +fi |
| 162 | +
|
| 163 | +# The original macro has a bunch of other tests here, which we have removed |
| 164 | +# because (a) Postgres doesn't need them, and (b) $acx_pthread_ok is not |
| 165 | +# meaningful at this point. |
| 166 | +
|
| 167 | +AC_SUBST(PTHREAD_LIBS) |
| 168 | +AC_SUBST(PTHREAD_CFLAGS) |
| 169 | +
|
| 170 | +AC_LANG_RESTORE |
| 171 | +])dnl ACX_PTHREAD |