summaryrefslogtreecommitdiff
path: root/m4/pthread_sigmask.m4
blob: 5b3e1cad327deb4d044ac94e485cf958dcddaa6d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
# pthread_sigmask.m4 serial 16
dnl Copyright (C) 2011-2016 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.

AC_DEFUN([gl_FUNC_PTHREAD_SIGMASK],
[
  AC_REQUIRE([gl_SIGNAL_H_DEFAULTS])

  AC_CHECK_FUNCS_ONCE([pthread_sigmask])
  LIB_PTHREAD_SIGMASK=

  dnl Test whether the gnulib module 'threadlib' is in use.
  dnl Some packages like Emacs use --avoid=threadlib.
  dnl Write the symbol in such a way that it does not cause 'aclocal' to pick
  dnl the threadlib.m4 file that is installed in $PREFIX/share/aclocal/.
  m4_ifdef([gl_][THREADLIB], [
    AC_REQUIRE([gl_][THREADLIB])

    if test "$gl_threads_api" = posix; then
      if test $ac_cv_func_pthread_sigmask = yes; then
        dnl pthread_sigmask is available without -lpthread.
        :
      else
        if test -n "$LIBMULTITHREAD"; then
          AC_CACHE_CHECK([for pthread_sigmask in $LIBMULTITHREAD],
            [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD],
            [gl_save_LIBS="$LIBS"
             LIBS="$LIBS $LIBMULTITHREAD"
             AC_LINK_IFELSE(
               [AC_LANG_PROGRAM(
                  [[#include <pthread.h>
                    #include <signal.h>
                  ]],
                  [[return pthread_sigmask (0, (sigset_t *) 0, (sigset_t *) 0);]])
               ],
               [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD=yes],
               [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD=no])
             LIBS="$gl_save_LIBS"
            ])
          if test $gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD = yes; then
            AC_CACHE_CHECK([whether pthread_sigmask is only a macro],
              [gl_cv_func_pthread_sigmask_is_macro],
              [gl_save_LIBS="$LIBS"
               LIBS="$LIBS $LIBMULTITHREAD"
               AC_LINK_IFELSE(
                 [AC_LANG_PROGRAM(
                    [[#include <pthread.h>
                      #include <signal.h>
                      #undef pthread_sigmask
                    ]],
                    [[return pthread_sigmask (0, (sigset_t *) 0, (sigset_t *) 0);]])
                 ],
                 [gl_cv_func_pthread_sigmask_is_macro=no],
                 [gl_cv_func_pthread_sigmask_is_macro=yes])
               LIBS="$gl_save_LIBS"
              ])
            if test $gl_cv_func_pthread_sigmask_is_macro = yes; then
              dnl On MinGW pthread_sigmask is just a macro which always returns 0.
              dnl It does not exist as a real function, which is required by POSIX.
              REPLACE_PTHREAD_SIGMASK=1
              gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD=no
            fi
          fi
          if test $gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD = yes; then
            dnl pthread_sigmask is available with -pthread or -lpthread.
            LIB_PTHREAD_SIGMASK="$LIBMULTITHREAD"
          else
            dnl pthread_sigmask is not available at all.
            HAVE_PTHREAD_SIGMASK=0
          fi
        else
          dnl pthread_sigmask is not available at all.
          HAVE_PTHREAD_SIGMASK=0
        fi
      fi
    else
      dnl pthread_sigmask may exist but does not interoperate with the chosen
      dnl multithreading facility.
      dnl If "$gl_threads_api" = pth, we could use the function pth_sigmask,
      dnl but it is equivalent to sigprocmask, so we choose to emulate
      dnl pthread_sigmask with sigprocmask also in this case. This yields fewer
      dnl link dependencies.
      if test $ac_cv_func_pthread_sigmask = yes; then
        REPLACE_PTHREAD_SIGMASK=1
      else
        HAVE_PTHREAD_SIGMASK=0
      fi
    fi
  ], [
    dnl The module 'threadlib' is not in use, due to --avoid=threadlib being
    dnl specified.
    dnl The package either has prepared CPPFLAGS and LIBS for use of POSIX:2008
    dnl threads, or wants to build single-threaded programs.
    if test $ac_cv_func_pthread_sigmask = yes; then
      dnl pthread_sigmask exists and does not require extra libraries.
      dnl Assume that it is declared.
      :
    else
      dnl pthread_sigmask either does not exist or needs extra libraries.
      HAVE_PTHREAD_SIGMASK=0
      dnl Define the symbol rpl_pthread_sigmask, not pthread_sigmask,
      dnl so as to not accidentally override the system's pthread_sigmask
      dnl symbol from libpthread. This is necessary on IRIX 6.5.
      REPLACE_PTHREAD_SIGMASK=1
    fi
  ])

  AC_SUBST([LIB_PTHREAD_SIGMASK])
  dnl We don't need a variable LTLIB_PTHREAD_SIGMASK, because when
  dnl "$gl_threads_api" = posix, $LTLIBMULTITHREAD and $LIBMULTITHREAD are the
  dnl same.

  dnl Now test for some bugs in the system function.
  if test $HAVE_PTHREAD_SIGMASK = 1; then
    AC_REQUIRE([AC_PROG_CC])
    AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles

    dnl On FreeBSD 6.4, HP-UX 11.31, Solaris 9, in programs that are not linked
    dnl with -lpthread, the pthread_sigmask() function always returns 0 and has
    dnl no effect.
    if test -z "$LIB_PTHREAD_SIGMASK"; then
      case " $LIBS " in
        *' -pthread '*) ;;
        *' -lpthread '*) ;;
	*)
	  AC_CACHE_CHECK([whether pthread_sigmask works without -lpthread],
	    [gl_cv_func_pthread_sigmask_in_libc_works],
	    [
	      AC_RUN_IFELSE(
		[AC_LANG_SOURCE([[
		   #include <pthread.h>
		   #include <signal.h>
		   #include <stddef.h>
		   int main ()
		   {
		     sigset_t set;
		     sigemptyset (&set);
		     return pthread_sigmask (1729, &set, NULL) != 0;
		   }]])],
		[gl_cv_func_pthread_sigmask_in_libc_works=no],
		[gl_cv_func_pthread_sigmask_in_libc_works=yes],
		[
		 changequote(,)dnl
		 case "$host_os" in
		   freebsd* | hpux* | solaris | solaris2.[2-9]*)
		     gl_cv_func_pthread_sigmask_in_libc_works="guessing no";;
		   *)
		     gl_cv_func_pthread_sigmask_in_libc_works="guessing yes";;
		 esac
		 changequote([,])dnl
		])
	    ])
	  case "$gl_cv_func_pthread_sigmask_in_libc_works" in
	    *no)
	      REPLACE_PTHREAD_SIGMASK=1
	      AC_DEFINE([PTHREAD_SIGMASK_INEFFECTIVE], [1],
		[Define to 1 if pthread_sigmask may return 0 and have no effect.])
	      ;;
	  esac;;
      esac
    fi

    dnl On Cygwin 1.7.5, the pthread_sigmask() has a wrong return value
    dnl convention: Upon failure, it returns -1 and sets errno.
    AC_CACHE_CHECK([whether pthread_sigmask returns error numbers],
      [gl_cv_func_pthread_sigmask_return_works],
      [
        gl_save_LIBS="$LIBS"
        LIBS="$LIBS $LIB_PTHREAD_SIGMASK"
        AC_RUN_IFELSE(
          [AC_LANG_SOURCE([[
#include <pthread.h>
#include <signal.h>
#include <stddef.h>
int main ()
{
  sigset_t set;
  sigemptyset (&set);
  if (pthread_sigmask (1729, &set, NULL) == -1)
    return 1;
  return 0;
}]])],
          [gl_cv_func_pthread_sigmask_return_works=yes],
          [gl_cv_func_pthread_sigmask_return_works=no],
          [case "$host_os" in
             cygwin*)
               gl_cv_func_pthread_sigmask_return_works="guessing no";;
             *)
               gl_cv_func_pthread_sigmask_return_works="guessing yes";;
           esac
          ])
        LIBS="$gl_save_LIBS"
      ])
    case "$gl_cv_func_pthread_sigmask_return_works" in
      *no)
        REPLACE_PTHREAD_SIGMASK=1
        AC_DEFINE([PTHREAD_SIGMASK_FAILS_WITH_ERRNO], [1],
          [Define to 1 if pthread_sigmask(), when it fails, returns -1 and sets errno.])
        ;;
    esac

    dnl On IRIX 6.5, in a single-threaded program, pending signals are not
    dnl immediately delivered when they are unblocked through pthread_sigmask,
    dnl only a little while later.
    AC_CACHE_CHECK([whether pthread_sigmask unblocks signals correctly],
      [gl_cv_func_pthread_sigmask_unblock_works],
      [
        case "$host_os" in
          irix*)
            gl_cv_func_pthread_sigmask_unblock_works="guessing no";;
          *)
            gl_cv_func_pthread_sigmask_unblock_works="guessing yes";;
        esac
        m4_ifdef([gl_][THREADLIB],
          [dnl Link against $LIBMULTITHREAD, not only $LIB_PTHREAD_SIGMASK.
           dnl Otherwise we get a false positive on those platforms where
           dnl $gl_cv_func_pthread_sigmask_in_libc_works is "no".
           gl_save_LIBS=$LIBS
           LIBS="$LIBS $LIBMULTITHREAD"])
        AC_RUN_IFELSE(
          [AC_LANG_SOURCE([[
#include <pthread.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
static volatile int sigint_occurred;
static void
sigint_handler (int sig)
{
  sigint_occurred++;
}
int main ()
{
  sigset_t set;
  int pid = getpid ();
  char command[80];
  signal (SIGINT, sigint_handler);
  sigemptyset (&set);
  sigaddset (&set, SIGINT);
  if (!(pthread_sigmask (SIG_BLOCK, &set, NULL) == 0))
    return 1;
  sprintf (command, "sh -c 'sleep 1; kill -%d %d' &", SIGINT, pid);
  if (!(system (command) == 0))
    return 2;
  sleep (2);
  if (!(sigint_occurred == 0))
    return 3;
  if (!(pthread_sigmask (SIG_UNBLOCK, &set, NULL) == 0))
    return 4;
  if (!(sigint_occurred == 1)) /* This fails on IRIX.  */
    return 5;
  return 0;
}]])],
          [:],
          [gl_cv_func_pthread_sigmask_unblock_works=no],
          [:])
        m4_ifdef([gl_][THREADLIB], [LIBS=$gl_save_LIBS])
      ])
    case "$gl_cv_func_pthread_sigmask_unblock_works" in
      *no)
        REPLACE_PTHREAD_SIGMASK=1
        AC_DEFINE([PTHREAD_SIGMASK_UNBLOCK_BUG], [1],
          [Define to 1 if pthread_sigmask() unblocks signals incorrectly.])
        ;;
    esac
  fi
])

# Prerequisite of lib/pthread_sigmask.c.
AC_DEFUN([gl_PREREQ_PTHREAD_SIGMASK],
[
  if test $HAVE_PTHREAD_SIGMASK = 1; then
    AC_DEFINE([HAVE_PTHREAD_SIGMASK], [1],
      [Define to 1 if the pthread_sigmask function can be used (despite bugs).])
  fi
])