windows-timedrecmutex: New module.

* lib/windows-timedrecmutex.h: New file, based on windows-recmutex.h.
* lib/windows-timedrecmutex.c: New file, based on windows-recmutex.c.
* modules/windows-timedrecmutex: New file.

4 files changed, 367 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 403836876c..5e416fede8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2019-06-20  Bruno Haible  <bruno@clisp.org>
 
+	windows-timedrecmutex: New module.
+	* lib/windows-timedrecmutex.h: New file, based on windows-recmutex.h.
+	* lib/windows-timedrecmutex.c: New file, based on windows-recmutex.c.
+	* modules/windows-timedrecmutex: New file.
+
+2019-06-20  Bruno Haible  <bruno@clisp.org>
+
 	windows-timedmutex: New module.
 	* lib/windows-timedmutex.h: New file, based on windows-mutex.h.
 	* lib/windows-timedmutex.c: New file, based on windows-mutex.c.
diff --git a/lib/windows-timedrecmutex.c b/lib/windows-timedrecmutex.c
new file mode 100644
index 0000000000..6f91d46daa
--- /dev/null
+++ b/lib/windows-timedrecmutex.c
@@ -0,0 +1,267 @@
+/* Timed recursive mutexes (native Windows implementation).
+   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-win32.h.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include "windows-timedrecmutex.h"
+
+#include <errno.h>
+#include <stdlib.h>
+#include <sys/time.h>
+
+int
+glwthread_timedrecmutex_init (glwthread_timedrecmutex_t *mutex)
+{
+  mutex->owner = 0;
+  mutex->depth = 0;
+  /* Attempt to allocate an auto-reset event object.  */
+  /* CreateEvent
+     <https://docs.microsoft.com/en-us/windows/desktop/api/synchapi/nf-synchapi-createeventa> */
+  HANDLE event = CreateEvent (NULL, FALSE, FALSE, NULL);
+  if (event == INVALID_HANDLE_VALUE)
+    return EAGAIN;
+  mutex->event = event;
+  InitializeCriticalSection (&mutex->lock);
+  mutex->guard.done = 1;
+  return 0;
+}
+
+int
+glwthread_timedrecmutex_lock (glwthread_timedrecmutex_t *mutex)
+{
+  if (!mutex->guard.done)
+    {
+      if (InterlockedIncrement (&mutex->guard.started) == 0)
+        {
+          /* This thread is the first one to need this mutex.
+             Initialize it.  */
+          int err = glwthread_timedrecmutex_init (mutex);
+          if (err != 0)
+            {
+              /* Undo increment.  */
+              InterlockedDecrement (&mutex->guard.started);
+              return err;
+            }
+        }
+      else
+        {
+          /* Don't let mutex->guard.started grow and wrap around.  */
+          InterlockedDecrement (&mutex->guard.started);
+          /* Yield the CPU while waiting for another thread to finish
+             initializing this mutex.  */
+          while (!mutex->guard.done)
+            Sleep (0);
+        }
+    }
+  {
+    DWORD self = GetCurrentThreadId ();
+    if (mutex->owner != self)
+      {
+        EnterCriticalSection (&mutex->lock);
+        mutex->owner = self;
+      }
+    if (++(mutex->depth) == 0) /* wraparound? */
+      {
+        mutex->depth--;
+        return EAGAIN;
+      }
+  }
+  return 0;
+}
+
+int
+glwthread_timedrecmutex_trylock (glwthread_timedrecmutex_t *mutex)
+{
+  if (!mutex->guard.done)
+    {
+      if (InterlockedIncrement (&mutex->guard.started) == 0)
+        {
+          /* This thread is the first one to need this mutex.
+             Initialize it.  */
+          int err = glwthread_timedrecmutex_init (mutex);
+          if (err != 0)
+            {
+              /* Undo increment.  */
+              InterlockedDecrement (&mutex->guard.started);
+              return err;
+            }
+        }
+      else
+        {
+          /* Don't let mutex->guard.started grow and wrap around.  */
+          InterlockedDecrement (&mutex->guard.started);
+          /* Let another thread finish initializing this mutex, and let it also
+             lock this mutex.  */
+          return EBUSY;
+        }
+    }
+  {
+    DWORD self = GetCurrentThreadId ();
+    if (mutex->owner != self)
+      {
+        if (!TryEnterCriticalSection (&mutex->lock))
+          return EBUSY;
+        mutex->owner = self;
+      }
+    if (++(mutex->depth) == 0) /* wraparound? */
+      {
+        mutex->depth--;
+        return EAGAIN;
+      }
+  }
+  return 0;
+}
+
+int
+glwthread_timedrecmutex_timedlock (glwthread_timedrecmutex_t *mutex,
+                                   const struct timespec *abstime)
+{
+  if (!mutex->guard.done)
+    {
+      if (InterlockedIncrement (&mutex->guard.started) == 0)
+        {
+          /* This thread is the first one to need this mutex.
+             Initialize it.  */
+          int err = glwthread_timedrecmutex_init (mutex);
+          if (err != 0)
+            {
+              /* Undo increment.  */
+              InterlockedDecrement (&mutex->guard.started);
+              return err;
+            }
+        }
+      else
+        {
+          /* Don't let mutex->guard.started grow and wrap around.  */
+          InterlockedDecrement (&mutex->guard.started);
+          /* Yield the CPU while waiting for another thread to finish
+             initializing this mutex.  */
+          while (!mutex->guard.done)
+            Sleep (0);
+        }
+    }
+
+  {
+    DWORD self = GetCurrentThreadId ();
+    if (mutex->owner != self)
+      {
+        /* POSIX says:
+            "Under no circumstance shall the function fail with a timeout if
+             the mutex can be locked immediately. The validity of the abstime
+             parameter need not be checked if the mutex can be locked
+             immediately."
+           Therefore start the loop with a TryEnterCriticalSection call.  */
+        for (;;)
+          {
+            if (TryEnterCriticalSection (&mutex->lock))
+              break;
+
+            {
+              struct timeval currtime;
+              DWORD timeout;
+              DWORD result;
+
+              gettimeofday (&currtime, NULL);
+
+              /* Wait until another thread signals the event or until the
+                 abstime passes.  */
+              if (currtime.tv_sec > abstime->tv_sec)
+                timeout = 0;
+              else
+                {
+                  unsigned long seconds = abstime->tv_sec - currtime.tv_sec;
+                  timeout = seconds * 1000;
+                  if (timeout / 1000 != seconds) /* overflow? */
+                    timeout = INFINITE;
+                  else
+                    {
+                      long milliseconds =
+                        abstime->tv_nsec / 1000000 - currtime.tv_usec / 1000;
+                      if (milliseconds >= 0)
+                        {
+                          timeout += milliseconds;
+                          if (timeout < milliseconds) /* overflow? */
+                            timeout = INFINITE;
+                        }
+                      else
+                        {
+                          if (timeout >= - milliseconds)
+                            timeout -= (- milliseconds);
+                          else
+                            timeout = 0;
+                        }
+                    }
+                }
+              if (timeout == 0)
+                return ETIMEDOUT;
+
+              /* WaitForSingleObject
+                 <https://docs.microsoft.com/en-us/windows/desktop/api/synchapi/nf-synchapi-waitforsingleobject> */
+              result = WaitForSingleObject (mutex->event, timeout);
+              if (result == WAIT_FAILED)
+                abort ();
+              if (result == WAIT_TIMEOUT)
+                return ETIMEDOUT;
+              /* Another thread has just unlocked the mutex.  We have good chances at
+                 locking it now.  */
+            }
+          }
+        mutex->owner = self;
+      }
+    if (++(mutex->depth) == 0) /* wraparound? */
+      {
+        mutex->depth--;
+        return EAGAIN;
+      }
+  }
+  return 0;
+}
+
+int
+glwthread_timedrecmutex_unlock (glwthread_timedrecmutex_t *mutex)
+{
+  if (mutex->owner != GetCurrentThreadId ())
+    return EPERM;
+  if (mutex->depth == 0)
+    return EINVAL;
+  if (--(mutex->depth) == 0)
+    {
+      mutex->owner = 0;
+      LeaveCriticalSection (&mutex->lock);
+      /* Notify one of the threads that were waiting with a timeout.  */
+      /* SetEvent
+         <https://docs.microsoft.com/en-us/windows/desktop/api/synchapi/nf-synchapi-setevent> */
+      SetEvent (mutex->event);
+    }
+  return 0;
+}
+
+int
+glwthread_timedrecmutex_destroy (glwthread_timedrecmutex_t *mutex)
+{
+  if (mutex->owner != 0)
+    return EBUSY;
+  DeleteCriticalSection (&mutex->lock);
+  /* CloseHandle
+     <https://docs.microsoft.com/en-us/windows/desktop/api/handleapi/nf-handleapi-closehandle> */
+  CloseHandle (mutex->event);
+  mutex->guard.done = 0;
+  return 0;
+}
diff --git a/lib/windows-timedrecmutex.h b/lib/windows-timedrecmutex.h
new file mode 100644
index 0000000000..c0d2d3b75a
--- /dev/null
+++ b/lib/windows-timedrecmutex.h
@@ -0,0 +1,62 @@
+/* Timed recursive mutexes (native Windows implementation).
+   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-win32.h.  */
+
+#ifndef _WINDOWS_TIMEDRECMUTEX_H
+#define _WINDOWS_TIMEDRECMUTEX_H
+
+#define WIN32_LEAN_AND_MEAN  /* avoid including junk */
+#include <windows.h>
+
+#include <time.h>
+
+#include "windows-spinlock.h"
+
+/* The native Windows documentation says that CRITICAL_SECTION already
+   implements a recursive lock.  But we need not rely on it: It's easy to
+   implement a recursive lock without this assumption.  */
+
+typedef struct
+        {
+          glwthread_spinlock_t guard; /* protects the initialization */
+          DWORD owner;
+          unsigned long depth;
+          HANDLE event;
+          CRITICAL_SECTION lock;
+        }
+        glwthread_timedrecmutex_t;
+
+#define GLWTHREAD_TIMEDRECMUTEX_INIT { GLWTHREAD_SPINLOCK_INIT, 0, 0 }
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern int glwthread_timedrecmutex_init (glwthread_timedrecmutex_t *mutex);
+extern int glwthread_timedrecmutex_lock (glwthread_timedrecmutex_t *mutex);
+extern int glwthread_timedrecmutex_trylock (glwthread_timedrecmutex_t *mutex);
+extern int glwthread_timedrecmutex_timedlock (glwthread_timedrecmutex_t *mutex,
+                                              const struct timespec *abstime);
+extern int glwthread_timedrecmutex_unlock (glwthread_timedrecmutex_t *mutex);
+extern int glwthread_timedrecmutex_destroy (glwthread_timedrecmutex_t *mutex);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _WINDOWS_TIMEDRECMUTEX_H */
diff --git a/modules/windows-timedrecmutex b/modules/windows-timedrecmutex
new file mode 100644
index 0000000000..116817a981
--- /dev/null
+++ b/modules/windows-timedrecmutex
@@ -0,0 +1,31 @@
+Description:
+Timed recursive mutexes (native Windows implementation).
+
+Files:
+lib/windows-timedrecmutex.h
+lib/windows-timedrecmutex.c
+lib/windows-spinlock.h
+
+Depends-on:
+errno
+time
+gettimeofday
+
+configure.ac:
+AC_REQUIRE([AC_CANONICAL_HOST])
+case "$host_os" in
+  mingw*)
+    AC_LIBOBJ([windows-timedrecmutex])
+    ;;
+esac
+
+Makefile.am:
+
+Include:
+"windows-timedrecmutex.h"
+
+License:
+LGPLv2+
+
+Maintainer:
+all