mtx: New module.

* lib/mtx.c: New file.
* modules/mtx: New file.
* doc/posix-functions/call_once.texi: Mention the new module.
* doc/posix-functions/mtx_init.texi: Likewise.
* doc/posix-functions/mtx_lock.texi: Likewise.
* doc/posix-functions/mtx_trylock.texi: Likewise.
* doc/posix-functions/mtx_timedlock.texi: Likewise.
* doc/posix-functions/mtx_unlock.texi: Likewise.
* doc/posix-functions/mtx_destroy.texi: Likewise.

10 files changed, 363 insertions, 28 deletions

diff --git a/ChangeLog b/ChangeLog
index 5d96988342..0e73bd689b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,18 @@
 2019-06-20  Bruno Haible  <bruno@clisp.org>
 
+	mtx: New module.
+	* lib/mtx.c: New file.
+	* modules/mtx: New file.
+	* doc/posix-functions/call_once.texi: Mention the new module.
+	* doc/posix-functions/mtx_init.texi: Likewise.
+	* doc/posix-functions/mtx_lock.texi: Likewise.
+	* doc/posix-functions/mtx_trylock.texi: Likewise.
+	* doc/posix-functions/mtx_timedlock.texi: Likewise.
+	* doc/posix-functions/mtx_unlock.texi: Likewise.
+	* doc/posix-functions/mtx_destroy.texi: Likewise.
+
+2019-06-20  Bruno Haible  <bruno@clisp.org>
+
 	thrd: New module.
 	* lib/thrd.c: New file.
 	* m4/thrd.m4: New file.
diff --git a/doc/posix-functions/call_once.texi b/doc/posix-functions/call_once.texi
index c3b10fb5a4..84b9dfe1f2 100644
--- a/doc/posix-functions/call_once.texi
+++ b/doc/posix-functions/call_once.texi
@@ -10,15 +10,15 @@ Documentation:@*
 @url{https://www.gnu.org/software/libc/manual/html_node/Call-Once.html}.
 @end ifnotinfo
 
-Gnulib module: ---
+Gnulib module: mtx
 
 Portability problems fixed by Gnulib:
 @itemize
+@item
+This function is missing on many platforms:
+glibc 2.27, Mac OS X 10.5, FreeBSD 9.3, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 7.1, HP-UX 11.31, IRIX 6.5, OSF/1 5.1, Solaris 11.3, Cygwin, mingw, MSVC 14, Interix 3.5, BeOS, Android 9.0.
 @end itemize
 
 Portability problems not fixed by Gnulib:
 @itemize
-@item
-This function is missing on many platforms:
-glibc 2.27, Mac OS X 10.5, FreeBSD 9.3, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 7.1, HP-UX 11.31, IRIX 6.5, OSF/1 5.1, Solaris 11.3, Cygwin, mingw, MSVC 14, Interix 3.5, BeOS, Android 9.0.
 @end itemize
diff --git a/doc/posix-functions/mtx_destroy.texi b/doc/posix-functions/mtx_destroy.texi
index ec8fe870ac..fda5048167 100644
--- a/doc/posix-functions/mtx_destroy.texi
+++ b/doc/posix-functions/mtx_destroy.texi
@@ -10,15 +10,15 @@ Documentation:@*
 @url{https://www.gnu.org/software/libc/manual/html_node/ISO-C-Mutexes.html}.
 @end ifnotinfo
 
-Gnulib module: ---
+Gnulib module: mtx
 
 Portability problems fixed by Gnulib:
 @itemize
+@item
+This function is missing on many platforms:
+glibc 2.27, Mac OS X 10.5, FreeBSD 9.3, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 7.1, HP-UX 11.31, IRIX 6.5, OSF/1 5.1, Solaris 11.3, Cygwin, mingw, MSVC 14, Interix 3.5, BeOS, Android 9.0.
 @end itemize
 
 Portability problems not fixed by Gnulib:
 @itemize
-@item
-This function is missing on many platforms:
-glibc 2.27, Mac OS X 10.5, FreeBSD 9.3, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 7.1, HP-UX 11.31, IRIX 6.5, OSF/1 5.1, Solaris 11.3, Cygwin, mingw, MSVC 14, Interix 3.5, BeOS, Android 9.0.
 @end itemize
diff --git a/doc/posix-functions/mtx_init.texi b/doc/posix-functions/mtx_init.texi
index 867f6a259a..297ad34c8c 100644
--- a/doc/posix-functions/mtx_init.texi
+++ b/doc/posix-functions/mtx_init.texi
@@ -10,15 +10,15 @@ Documentation:@*
 @url{https://www.gnu.org/software/libc/manual/html_node/ISO-C-Mutexes.html}.
 @end ifnotinfo
 
-Gnulib module: ---
+Gnulib module: mtx
 
 Portability problems fixed by Gnulib:
 @itemize
+@item
+This function is missing on many platforms:
+glibc 2.27, Mac OS X 10.5, FreeBSD 9.3, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 7.1, HP-UX 11.31, IRIX 6.5, OSF/1 5.1, Solaris 11.3, Cygwin, mingw, MSVC 14, Interix 3.5, BeOS, Android 9.0.
 @end itemize
 
 Portability problems not fixed by Gnulib:
 @itemize
-@item
-This function is missing on many platforms:
-glibc 2.27, Mac OS X 10.5, FreeBSD 9.3, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 7.1, HP-UX 11.31, IRIX 6.5, OSF/1 5.1, Solaris 11.3, Cygwin, mingw, MSVC 14, Interix 3.5, BeOS, Android 9.0.
 @end itemize
diff --git a/doc/posix-functions/mtx_lock.texi b/doc/posix-functions/mtx_lock.texi
index 8e43992efe..958589d290 100644
--- a/doc/posix-functions/mtx_lock.texi
+++ b/doc/posix-functions/mtx_lock.texi
@@ -10,15 +10,15 @@ Documentation:@*
 @url{https://www.gnu.org/software/libc/manual/html_node/ISO-C-Mutexes.html}.
 @end ifnotinfo
 
-Gnulib module: ---
+Gnulib module: mtx
 
 Portability problems fixed by Gnulib:
 @itemize
+@item
+This function is missing on many platforms:
+glibc 2.27, Mac OS X 10.5, FreeBSD 9.3, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 7.1, HP-UX 11.31, IRIX 6.5, OSF/1 5.1, Solaris 11.3, Cygwin, mingw, MSVC 14, Interix 3.5, BeOS, Android 9.0.
 @end itemize
 
 Portability problems not fixed by Gnulib:
 @itemize
-@item
-This function is missing on many platforms:
-glibc 2.27, Mac OS X 10.5, FreeBSD 9.3, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 7.1, HP-UX 11.31, IRIX 6.5, OSF/1 5.1, Solaris 11.3, Cygwin, mingw, MSVC 14, Interix 3.5, BeOS, Android 9.0.
 @end itemize
diff --git a/doc/posix-functions/mtx_timedlock.texi b/doc/posix-functions/mtx_timedlock.texi
index 31e766ee42..d42f1aee94 100644
--- a/doc/posix-functions/mtx_timedlock.texi
+++ b/doc/posix-functions/mtx_timedlock.texi
@@ -10,15 +10,15 @@ Documentation:@*
 @url{https://www.gnu.org/software/libc/manual/html_node/ISO-C-Mutexes.html}.
 @end ifnotinfo
 
-Gnulib module: ---
+Gnulib module: mtx
 
 Portability problems fixed by Gnulib:
 @itemize
+@item
+This function is missing on many platforms:
+glibc 2.27, Mac OS X 10.5, FreeBSD 9.3, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 7.1, HP-UX 11.31, IRIX 6.5, OSF/1 5.1, Solaris 11.3, Cygwin, mingw, MSVC 14, Interix 3.5, BeOS, Android 9.0.
 @end itemize
 
 Portability problems not fixed by Gnulib:
 @itemize
-@item
-This function is missing on many platforms:
-glibc 2.27, Mac OS X 10.5, FreeBSD 9.3, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 7.1, HP-UX 11.31, IRIX 6.5, OSF/1 5.1, Solaris 11.3, Cygwin, mingw, MSVC 14, Interix 3.5, BeOS, Android 9.0.
 @end itemize
diff --git a/doc/posix-functions/mtx_trylock.texi b/doc/posix-functions/mtx_trylock.texi
index 26c38d6dbd..e5beb6485e 100644
--- a/doc/posix-functions/mtx_trylock.texi
+++ b/doc/posix-functions/mtx_trylock.texi
@@ -10,15 +10,15 @@ Documentation:@*
 @url{https://www.gnu.org/software/libc/manual/html_node/ISO-C-Mutexes.html}.
 @end ifnotinfo
 
-Gnulib module: ---
+Gnulib module: mtx
 
 Portability problems fixed by Gnulib:
 @itemize
+@item
+This function is missing on many platforms:
+glibc 2.27, Mac OS X 10.5, FreeBSD 9.3, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 7.1, HP-UX 11.31, IRIX 6.5, OSF/1 5.1, Solaris 11.3, Cygwin, mingw, MSVC 14, Interix 3.5, BeOS, Android 9.0.
 @end itemize
 
 Portability problems not fixed by Gnulib:
 @itemize
-@item
-This function is missing on many platforms:
-glibc 2.27, Mac OS X 10.5, FreeBSD 9.3, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 7.1, HP-UX 11.31, IRIX 6.5, OSF/1 5.1, Solaris 11.3, Cygwin, mingw, MSVC 14, Interix 3.5, BeOS, Android 9.0.
 @end itemize
diff --git a/doc/posix-functions/mtx_unlock.texi b/doc/posix-functions/mtx_unlock.texi
index e7779d8e62..f77ea17f21 100644
--- a/doc/posix-functions/mtx_unlock.texi
+++ b/doc/posix-functions/mtx_unlock.texi
@@ -10,15 +10,15 @@ Documentation:@*
 @url{https://www.gnu.org/software/libc/manual/html_node/ISO-C-Mutexes.html}.
 @end ifnotinfo
 
-Gnulib module: ---
+Gnulib module: mtx
 
 Portability problems fixed by Gnulib:
 @itemize
+@item
+This function is missing on many platforms:
+glibc 2.27, Mac OS X 10.5, FreeBSD 9.3, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 7.1, HP-UX 11.31, IRIX 6.5, OSF/1 5.1, Solaris 11.3, Cygwin, mingw, MSVC 14, Interix 3.5, BeOS, Android 9.0.
 @end itemize
 
 Portability problems not fixed by Gnulib:
 @itemize
-@item
-This function is missing on many platforms:
-glibc 2.27, Mac OS X 10.5, FreeBSD 9.3, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 7.1, HP-UX 11.31, IRIX 6.5, OSF/1 5.1, Solaris 11.3, Cygwin, mingw, MSVC 14, Interix 3.5, BeOS, Android 9.0.
 @end itemize
diff --git a/lib/mtx.c b/lib/mtx.c
new file mode 100644
index 0000000000..6acb8ae44c
--- /dev/null
+++ b/lib/mtx.c
@@ -0,0 +1,288 @@
+/* ISO C 11 locking in multithreaded situations.
+   Copyright (C) 2005-2019 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <https://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <bruno@clisp.org>, 2005, 2019.
+   Based on GCC's gthr-posix.h, gthr-posix95.h, gthr-win32.h.  */
+
+#include <config.h>
+
+#include <threads.h>
+
+#include <errno.h>
+
+#if defined _WIN32 && ! defined __CYGWIN__
+/* Use Windows threads.  */
+
+# define WIN32_LEAN_AND_MEAN  /* avoid including junk */
+# include <windows.h>
+
+# include <stdlib.h>
+
+#else
+/* Use POSIX threads.  */
+
+# include <pthread.h>
+
+#endif
+
+#if defined _WIN32 && ! defined __CYGWIN__
+/* Use Windows threads.  */
+
+int
+mtx_init (mtx_t *mutex, int type)
+{
+  switch (type)
+    {
+    case mtx_plain:
+      glwthread_mutex_init (&mutex->u.u_mutex);
+      break;
+    case mtx_plain | mtx_recursive:
+      glwthread_recmutex_init (&mutex->u.u_recmutex);
+      break;
+    case mtx_timed:
+      if (glwthread_timedmutex_init (&mutex->u.u_timedmutex) != 0)
+        return thrd_error;
+      break;
+    case mtx_timed | mtx_recursive:
+      if (glwthread_timedrecmutex_init (&mutex->u.u_timedrecmutex) != 0)
+        return thrd_error;
+      break;
+    default:
+      return thrd_error;
+    }
+  mutex->type = type;
+  return thrd_success;
+}
+
+int
+mtx_lock (mtx_t *mutex)
+{
+  int err;
+
+  switch (mutex->type)
+    {
+    case mtx_plain:
+      err = glwthread_mutex_lock (&mutex->u.u_mutex);
+      break;
+    case mtx_plain | mtx_recursive:
+      err = glwthread_recmutex_lock (&mutex->u.u_recmutex);
+      break;
+    case mtx_timed:
+      err = glwthread_timedmutex_lock (&mutex->u.u_timedmutex);
+      break;
+    case mtx_timed | mtx_recursive:
+      err = glwthread_timedrecmutex_lock (&mutex->u.u_timedrecmutex);
+      break;
+    default:
+      abort ();
+    }
+  return (err == 0 ? thrd_success : thrd_error);
+}
+
+int
+mtx_trylock (mtx_t *mutex)
+{
+  int err;
+
+  switch (mutex->type)
+    {
+    case mtx_plain:
+      err = glwthread_mutex_trylock (&mutex->u.u_mutex);
+      break;
+    case mtx_plain | mtx_recursive:
+      err = glwthread_recmutex_trylock (&mutex->u.u_recmutex);
+      break;
+    case mtx_timed:
+      err = glwthread_timedmutex_trylock (&mutex->u.u_timedmutex);
+      break;
+    case mtx_timed | mtx_recursive:
+      err = glwthread_timedrecmutex_trylock (&mutex->u.u_timedrecmutex);
+      break;
+    default:
+      abort ();
+    }
+  return (err == 0 ? thrd_success : err == EBUSY ? thrd_busy : thrd_error);
+}
+
+int
+mtx_timedlock (mtx_t *mutex, const struct timespec *abstime)
+{
+  int err;
+
+  switch (mutex->type)
+    {
+    case mtx_plain:
+    case mtx_plain | mtx_recursive:
+      return thrd_error;
+    case mtx_timed:
+      err = glwthread_timedmutex_timedlock (&mutex->u.u_timedmutex, abstime);
+      break;
+    case mtx_timed | mtx_recursive:
+      err =
+        glwthread_timedrecmutex_timedlock (&mutex->u.u_timedrecmutex, abstime);
+      break;
+    default:
+      abort ();
+    }
+  return (err == 0 ? thrd_success : err == EBUSY ? thrd_busy : thrd_error);
+}
+
+int
+mtx_unlock (mtx_t *mutex)
+{
+  int err;
+
+  switch (mutex->type)
+    {
+    case mtx_plain:
+      err = glwthread_mutex_unlock (&mutex->u.u_mutex);
+      break;
+    case mtx_plain | mtx_recursive:
+      err = glwthread_recmutex_unlock (&mutex->u.u_recmutex);
+      break;
+    case mtx_timed:
+      err = glwthread_timedmutex_unlock (&mutex->u.u_timedmutex);
+      break;
+    case mtx_timed | mtx_recursive:
+      err = glwthread_timedrecmutex_unlock (&mutex->u.u_timedrecmutex);
+      break;
+    default:
+      abort ();
+    }
+  return (err == 0 ? thrd_success : thrd_error);
+}
+
+void
+mtx_destroy (mtx_t *mutex)
+{
+  switch (mutex->type)
+    {
+    case mtx_plain:
+      glwthread_mutex_destroy (&mutex->u.u_mutex);
+      break;
+    case mtx_plain | mtx_recursive:
+      glwthread_recmutex_destroy (&mutex->u.u_recmutex);
+      break;
+    case mtx_timed:
+      glwthread_timedmutex_destroy (&mutex->u.u_timedmutex);
+      break;
+    case mtx_timed | mtx_recursive:
+      glwthread_timedrecmutex_destroy (&mutex->u.u_timedrecmutex);
+      break;
+    default:
+      abort ();
+    }
+}
+
+void
+call_once (once_flag *flagp, void (*func) (void))
+{
+  glwthread_once (flagp, func);
+}
+
+#else
+/* Use POSIX threads.  */
+
+int
+mtx_init (mtx_t *mutex, int type)
+{
+  switch (type)
+    {
+    case mtx_plain:
+    case mtx_timed:
+    case mtx_plain | mtx_recursive:
+    case mtx_timed | mtx_recursive:
+      break;
+    default:
+      return thrd_error;
+    }
+
+  if ((type & mtx_recursive) != 0)
+    {
+      pthread_mutexattr_t attributes;
+      int err;
+
+      err = pthread_mutexattr_init (&attributes);
+      if (err != 0)
+        return thrd_error;
+      err = pthread_mutexattr_settype (&attributes, PTHREAD_MUTEX_RECURSIVE);
+      if (err != 0)
+        {
+          pthread_mutexattr_destroy (&attributes);
+          return thrd_error;
+        }
+      err = pthread_mutex_init (mutex, &attributes);
+      if (err != 0)
+        {
+          pthread_mutexattr_destroy (&attributes);
+          return thrd_error;
+        }
+      err = pthread_mutexattr_destroy (&attributes);
+      if (err != 0)
+        return thrd_error;
+    }
+  else
+    {
+      int err = pthread_mutex_init (mutex, NULL);
+      if (err != 0)
+        return thrd_error;
+    }
+  return thrd_success;
+}
+
+int
+mtx_lock (mtx_t *mutex)
+{
+  int err = pthread_mutex_lock (mutex);
+  return (err == 0 ? thrd_success : thrd_error);
+}
+
+int
+mtx_trylock (mtx_t *mutex)
+{
+  int err = pthread_mutex_trylock (mutex);
+  return (err == 0 ? thrd_success : err == EBUSY ? thrd_busy : thrd_error);
+}
+
+int
+mtx_timedlock (mtx_t *mutex, const struct timespec *abstime)
+{
+  int err = pthread_mutex_timedlock (mutex, abstime);
+  return (err == 0 ? thrd_success :
+          err == ETIMEDOUT ? thrd_timedout :
+          thrd_error);
+}
+
+int
+mtx_unlock (mtx_t *mutex)
+{
+  int err = pthread_mutex_unlock (mutex);
+  return (err == 0 ? thrd_success : thrd_error);
+}
+
+void
+mtx_destroy (mtx_t *mutex)
+{
+  pthread_mutex_destroy (mutex);
+}
+
+void
+call_once (once_flag *flagp, void (*func) (void))
+{
+  pthread_once (flagp, func);
+}
+
+#endif
diff --git a/modules/mtx b/modules/mtx
new file mode 100644
index 0000000000..a1d2a8ad4c
--- /dev/null
+++ b/modules/mtx
@@ -0,0 +1,34 @@
+Description:
+ISO C 11 mutex functions.
+
+Files:
+lib/mtx.c
+
+Depends-on:
+threads-h
+pthread_mutex_timedlock
+windows-mutex
+windows-recmutex
+windows-timedmutex
+windows-timedrecmutex
+
+configure.ac:
+AC_REQUIRE([gl_THREADS_H])
+if test $HAVE_THREADS_H = 0; then
+  AC_LIBOBJ([mtx])
+fi
+gl_THREADS_MODULE_INDICATOR([mtx])
+
+Makefile.am:
+
+Include:
+<threads.h>
+
+Link:
+$(LTLIBSTDTHREAD) when linking with libtool, $(LIBSTDTHREAD) otherwise
+
+License:
+LGPLv2+
+
+Maintainer:
+all