New upstream version 1.3upstream/1.3upstream

1 files changed, 265 insertions, 0 deletions

diff --git a/tests/windows-timedmutex.c b/tests/windows-timedmutex.c
new file mode 100644
index 00000000..3833cab1
--- /dev/null
+++ b/tests/windows-timedmutex.c
@@ -0,0 +1,265 @@
+/* Timed mutexes (native Windows implementation).
+   Copyright (C) 2005-2024 Free Software Foundation, Inc.
+
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   This file 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 Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser 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-timedmutex.h"
+
+#include <errno.h>
+#include <stdlib.h>
+#include <sys/time.h>
+
+/* Don't assume that UNICODE is not defined.  */
+#undef CreateEvent
+#define CreateEvent CreateEventA
+
+int
+glwthread_timedmutex_init (glwthread_timedmutex_t *mutex)
+{
+  /* 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;
+  mutex->owner = 0;
+  InitializeCriticalSection (&mutex->lock);
+  mutex->guard.done = 1;
+  return 0;
+}
+
+int
+glwthread_timedmutex_lock (glwthread_timedmutex_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_timedmutex_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);
+        }
+    }
+  /* If this thread already owns the mutex, POSIX pthread_mutex_lock() is
+     required to deadlock here.  But let's not do that on purpose.  */
+  EnterCriticalSection (&mutex->lock);
+  {
+    DWORD self = GetCurrentThreadId ();
+    mutex->owner = self;
+  }
+  return 0;
+}
+
+int
+glwthread_timedmutex_trylock (glwthread_timedmutex_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_timedmutex_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;
+        }
+    }
+  if (!TryEnterCriticalSection (&mutex->lock))
+    return EBUSY;
+  {
+    DWORD self = GetCurrentThreadId ();
+    /* TryEnterCriticalSection succeeded.  This means that the mutex was either
+       previously unlocked (and thus mutex->owner == 0) or previously locked by
+       this thread (and thus mutex->owner == self).  Since the mutex is meant to
+       be plain, we need to fail in the latter case.  */
+    if (mutex->owner == self)
+      {
+        LeaveCriticalSection (&mutex->lock);
+        return EBUSY;
+      }
+    if (mutex->owner != 0)
+      abort ();
+    mutex->owner = self;
+  }
+  return 0;
+}
+
+int
+glwthread_timedmutex_timedlock (glwthread_timedmutex_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_timedmutex_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);
+        }
+    }
+
+  /* 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.  */
+      }
+    }
+  {
+    DWORD self = GetCurrentThreadId ();
+    /* TryEnterCriticalSection succeeded.  This means that the mutex was either
+       previously unlocked (and thus mutex->owner == 0) or previously locked by
+       this thread (and thus mutex->owner == self).  Since the mutex is meant to
+       be plain, it is useful to fail in the latter case.  */
+    if (mutex->owner == self)
+      {
+        LeaveCriticalSection (&mutex->lock);
+        return EDEADLK;
+      }
+    if (mutex->owner != 0)
+      abort ();
+    mutex->owner = self;
+  }
+  return 0;
+}
+
+int
+glwthread_timedmutex_unlock (glwthread_timedmutex_t *mutex)
+{
+  if (!mutex->guard.done)
+    return EINVAL;
+  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_timedmutex_destroy (glwthread_timedmutex_t *mutex)
+{
+  if (!mutex->guard.done)
+    return EINVAL;
+  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;
+}