postgresql/config/acx_pthread.m4
Bruce Momjian 30a06fe2c4 Unconditionally define:
-D_REENTRANT -D_THREAD_SAFE -D_POSIX_PTHREAD_SEMANTICS

for all ports.  It can't hurt if they are not supported, but it makes
our job easier for porting.

Should fix Darwin compile and other platforms without mucking with the
thread detection code.
2004-04-26 04:04:42 +00:00

204 lines
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dnl PGSGL: When updating, comment out port-specific part below;
dnl see the comment below with the word "PostgreSQL".
dnl
dnl Available from the GNU Autoconf Macro Archive at:
dnl http://www.gnu.org/software/ac-archive/htmldoc/acx_pthread.html
dnl
AC_DEFUN([ACX_PTHREAD], [
AC_REQUIRE([AC_CANONICAL_HOST])
AC_LANG_SAVE
AC_LANG_C
acx_pthread_ok=no
# We used to check for pthread.h first, but this fails if pthread.h
# requires special compiler flags (e.g. on True64 or Sequent).
# It gets checked for in the link test anyway.
# First of all, check if the user has set any of the PTHREAD_LIBS,
# etcetera environment variables, and if threads linking works using
# them:
if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then
save_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
save_LIBS="$LIBS"
LIBS="$PTHREAD_LIBS $LIBS"
AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS])
AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes)
AC_MSG_RESULT($acx_pthread_ok)
if test x"$acx_pthread_ok" = xno; then
PTHREAD_LIBS=""
PTHREAD_CFLAGS=""
fi
LIBS="$save_LIBS"
CFLAGS="$save_CFLAGS"
fi
# We must check for the threads library under a number of different
# names; the ordering is very important because some systems
# (e.g. DEC) have both -lpthread and -lpthreads, where one of the
# libraries is broken (non-POSIX).
# Create a list of thread flags to try. Items starting with a "-" are
# C compiler flags, and other items are library names, except for "none"
# which indicates that we try without any flags at all, and "pthread-config"
# which is a program returning the flags for the Pth emulation library.
acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"
# The ordering *is* (sometimes) important. Some notes on the
# individual items follow:
# pthreads: AIX (must check this before -lpthread)
# none: in case threads are in libc; should be tried before -Kthread and
# other compiler flags to prevent continual compiler warnings
# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h)
# -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)
# lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)
# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads)
# -pthreads: Solaris/gcc
# -mthreads: Mingw32/gcc, Lynx/gcc
# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it
# doesn't hurt to check since this sometimes defines pthreads too;
# also defines -D_REENTRANT)
# pthread: Linux, etcetera
# --thread-safe: KAI C++
# pthread-config: use pthread-config program (for GNU Pth library)
case "${host_cpu}-${host_os}" in
*solaris*)
# On Solaris (at least, for some versions), libc contains stubbed
# (non-functional) versions of the pthreads routines, so link-based
# tests will erroneously succeed. (We need to link with -pthread or
# -lpthread.) (The stubs are missing pthread_cleanup_push, or rather
# a function called by this macro, so we could check for that, but
# who knows whether they'll stub that too in a future libc.) So,
# we'll just look for -pthreads and -lpthread first:
acx_pthread_flags="-pthread -pthreads pthread -mt $acx_pthread_flags"
;;
esac
if test x"$acx_pthread_ok" = xno; then
for flag in $acx_pthread_flags; do
case $flag in
none)
AC_MSG_CHECKING([whether pthreads work without any flags])
;;
-*)
AC_MSG_CHECKING([whether pthreads work with $flag])
PTHREAD_CFLAGS="$flag"
;;
pthread-config)
AC_CHECK_PROG(acx_pthread_config, pthread-config, yes, no)
if test x"$acx_pthread_config" = xno; then continue; fi
PTHREAD_CFLAGS="`pthread-config --cflags`"
PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
;;
*)
AC_MSG_CHECKING([for the pthreads library -l$flag])
PTHREAD_LIBS="-l$flag"
;;
esac
save_LIBS="$LIBS"
save_CFLAGS="$CFLAGS"
LIBS="$PTHREAD_LIBS $LIBS"
CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
# Check for various functions. We must include pthread.h,
# since some functions may be macros. (On the Sequent, we
# need a special flag -Kthread to make this header compile.)
# We check for pthread_join because it is in -lpthread on IRIX
# while pthread_create is in libc. We check for pthread_attr_init
# due to DEC craziness with -lpthreads. We check for
# pthread_cleanup_push because it is one of the few pthread
# functions on Solaris that doesn't have a non-functional libc stub.
# We try pthread_create on general principles.
AC_TRY_LINK([#include <pthread.h>],
[pthread_t th; pthread_join(th, 0);
pthread_attr_init(0); pthread_cleanup_push(0, 0);
pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
[acx_pthread_ok=yes])
LIBS="$save_LIBS"
CFLAGS="$save_CFLAGS"
AC_MSG_RESULT($acx_pthread_ok)
if test "x$acx_pthread_ok" = xyes; then
break;
fi
PTHREAD_LIBS=""
PTHREAD_CFLAGS=""
done
fi
# Various other checks:
if test "x$acx_pthread_ok" = xyes; then
save_LIBS="$LIBS"
LIBS="$PTHREAD_LIBS $LIBS"
save_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
# Detect AIX lossage: threads are created detached by default
# and the JOINABLE attribute has a nonstandard name (UNDETACHED).
AC_MSG_CHECKING([for joinable pthread attribute])
AC_TRY_LINK([#include <pthread.h>],
[int attr=PTHREAD_CREATE_JOINABLE;],
ok=PTHREAD_CREATE_JOINABLE, ok=unknown)
if test x"$ok" = xunknown; then
AC_TRY_LINK([#include <pthread.h>],
[int attr=PTHREAD_CREATE_UNDETACHED;],
ok=PTHREAD_CREATE_UNDETACHED, ok=unknown)
fi
if test x"$ok" != xPTHREAD_CREATE_JOINABLE; then
AC_DEFINE(PTHREAD_CREATE_JOINABLE, $ok,
[Define to the necessary symbol if this constant
uses a non-standard name on your system.])
fi
AC_MSG_RESULT(${ok})
if test x"$ok" = xunknown; then
AC_MSG_WARN([we do not know how to create joinable pthreads])
fi
AC_MSG_CHECKING([if more special flags are required for pthreads])
flag=no
# We handle this ourselves in PostgreSQL
# case "${host_cpu}-${host_os}" in
# *-aix* | *-freebsd*) flag="-D_THREAD_SAFE";;
# *solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";;
# esac
AC_MSG_RESULT(${flag})
if test "x$flag" != xno; then
PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
fi
LIBS="$save_LIBS"
CFLAGS="$save_CFLAGS"
# More AIX lossage: must compile with cc_r
AC_CHECK_PROG(PTHREAD_CC, cc_r, cc_r, ${CC})
else
PTHREAD_CC="$CC"
fi
AC_SUBST(PTHREAD_LIBS)
AC_SUBST(PTHREAD_CFLAGS)
AC_SUBST(PTHREAD_CC)
# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
if test x"$acx_pthread_ok" = xyes; then
ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1])
:
else
acx_pthread_ok=no
$2
fi
AC_LANG_RESTORE
])dnl ACX_PTHREAD