gnulib/import/m4/lock.m4

   1 # lock.m4 serial 14
   2 dnl Copyright (C) 2005-2019 Free Software Foundation, Inc.
   3 dnl This file is free software; the Free Software Foundation
   4 dnl gives unlimited permission to copy and/or distribute it,
   5 dnl with or without modifications, as long as this notice is preserved.
   6
   7 dnl From Bruno Haible.
   8
   9 AC_DEFUN([gl_LOCK],
  10 [
  11   AC_REQUIRE([gl_THREADLIB])
  12   if test "$gl_threads_api" = posix; then
  13     # OSF/1 4.0 and Mac OS X 10.1 lack the pthread_rwlock_t type and the
  14     # pthread_rwlock_* functions.
  15     has_rwlock=false
  16     AC_CHECK_TYPE([pthread_rwlock_t],
  17       [has_rwlock=true
  18        AC_DEFINE([HAVE_PTHREAD_RWLOCK], [1],
  19          [Define if the POSIX multithreading library has read/write locks.])],
  20       [],
  21       [#include <pthread.h>])
  22     if $has_rwlock; then
  23       gl_PTHREAD_RWLOCK_RDLOCK_PREFER_WRITER
  24     fi
  25     # glibc defines PTHREAD_MUTEX_RECURSIVE as enum, not as a macro.
  26     AC_COMPILE_IFELSE([
  27       AC_LANG_PROGRAM(
  28         [[#include <pthread.h>]],
  29         [[
  30 #if __FreeBSD__ == 4
  31 error "No, in FreeBSD 4.0 recursive mutexes actually don't work."
  32 #elif (defined __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ \
  33        && __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 1070)
  34 error "No, in Mac OS X < 10.7 recursive mutexes actually don't work."
  35 #else
  36 int x = (int)PTHREAD_MUTEX_RECURSIVE;
  37 return !x;
  38 #endif
  39         ]])],
  40       [AC_DEFINE([HAVE_PTHREAD_MUTEX_RECURSIVE], [1],
  41          [Define if the <pthread.h> defines PTHREAD_MUTEX_RECURSIVE.])])
  42   fi
  43   gl_PREREQ_LOCK
  44 ])
  45
  46 # Prerequisites of lib/glthread/lock.c.
  47 AC_DEFUN([gl_PREREQ_LOCK], [:])