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diff --git a/libjava/classpath/gnu/java/awt/peer/gtk/GThreadMutex.java b/libjava/classpath/gnu/java/awt/peer/gtk/GThreadMutex.java
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+/* GThreadMutex.java -- Implements a mutex object for glib's gthread
+   abstraction, for use with GNU Classpath's --portable-native-sync option.
+   This is used in gthread-jni.c
+   
+   Copyright (C) 2004 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath 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.
+
+GNU Classpath 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 GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package gnu.java.awt.peer.gtk;
+
+/** Implements a mutex object for glib's gthread
+    abstraction, for use with GNU Classpath's --portable-native-sync option.
+    This is used in gthread-jni.c.
+
+    We use this object to implement the POSIX semantics for Mutexes.  They are
+    needed are needed for the function vector that is passed to glib's
+    g_thread subpackage's initialization function.
+
+    The GThreadMutex object itself serves as the Real Lock; if code has
+    entered the monitor for this GThreadMutex object (in Java language, if
+    it's synchronized on this object) then it holds the lock that this object
+    represents.
+
+    @author Steven Augart
+    May, 2004
+
+    
+*/
+   
+class GThreadMutex 
+{
+  /** Might "lock" be locked?  Is anyone waiting
+      to get that lock?  How long is the queue?
+
+      If zero, nobody holds a lock on this GThreadMutex object, and nobody is
+      trying to get one.   Before someone attempts to acquire a lock on this
+      object, they must increment potentialLockers.  After they release their
+      lock on this object, they must decrement potentialLockers.
+
+      Access to this field is guarded by synchronizing on the object
+      <code>lockForPotentialLockers</code>.
+
+      After construction, we only access this field via JNI.
+  */
+  volatile int potentialLockers;
+
+  /** An object to synchronize to if you want to examine or modify the
+      <code>potentialLockers</code> field.  Only hold this lock for brief
+      moments, just long enough to check or set the value of
+      <code>lockForPotentialLockers</code>.  
+      
+      We use this representation so that g_thread_mutex_trylock() will work
+      with the POSIX semantics.  This is the only case in which you ever hold a
+      lock on <code>lockForPotentialLockers</code> while trying to get another
+      lock -- if you are the mutex_trylock() implementation, and you have just
+      checked that <code>potentialLockers</code> has the value zero.  In that
+      case, mutex_trylock() holds the lock on lockForPotentialLockers so that
+      another thread calling mutex_trylock() or mutex_lock() won't increment
+      potentialLockers after we've checked it and before we've gained the lock
+      on the POSIX mutex.   Of course, in that case the operation of gaining
+      the POSIX lock itself will succeed immediately, and once it has
+      succeeded, trylock releases lockForPotentialLockers right away,
+      incremented to 1 (one).
+
+      After construction, we only access this field via JNI.
+  */     
+  Object lockForPotentialLockers;
+
+  GThreadMutex() 
+  {
+    potentialLockers = 0;
+    lockForPotentialLockers = new Object();
+  }
+}
+// Local Variables:
+// c-file-style: "gnu"
+// End: