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diff --git a/dep/src/zthread/RecursiveMutexImpl.cxx b/dep/src/zthread/RecursiveMutexImpl.cxx
new file mode 100644
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+++ b/dep/src/zthread/RecursiveMutexImpl.cxx
@@ -0,0 +1,286 @@
+/*
+ * Copyright (c) 2005, Eric Crahen
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is furnished
+ * to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#include "Debug.h"
+
+#include "RecursiveMutexImpl.h"
+#include "ThreadImpl.h"
+
+#include "zthread/Guard.h"
+
+#include <assert.h>
+#include <errno.h>
+#include <algorithm>
+
+namespace ZThread {
+
+  /**
+   * Create a new RecursiveMutexImpl
+   *
+   * @exception Initialization_Exception thrown if resources could not be
+   * properly allocated
+   */
+  RecursiveMutexImpl::RecursiveMutexImpl() 
+    : _owner(0), _count(0) {
+ 
+  }
+
+  /**
+   * Destroy this RecursiveMutexImpl and release its resources
+   */
+  RecursiveMutexImpl::~RecursiveMutexImpl() {
+
+#ifndef NDEBUG
+
+    // It is an error to destroy a mutex that has not been released
+    if(_owner != 0) { 
+
+      ZTDEBUG("** You are destroying a mutex which was never released. **\n");
+      assert(0); // Destroyed mutex while in use
+
+    }
+
+    if(!_waiters.empty()) { 
+
+      ZTDEBUG("** You are destroying a mutex which is blocking %d threads. **\n", _waiters.size());
+      assert(0); // Destroyed mutex while in use
+
+    }
+
+#endif
+
+  }
+
+
+  void RecursiveMutexImpl::acquire() {
+
+    // Get the monitor for the current thread
+    Monitor& m = ThreadImpl::current()->getMonitor();
+    Monitor::STATE state;
+
+    Guard<FastLock> g1(_lock);
+      
+    // If there is an entry count and the current thread is 
+    // the owner, increment the count and continue.
+    if(_owner == &m) 
+      _count++;
+
+    else {
+
+      // Acquire the lock if it is free and there are no waiting threads
+      if(_owner == 0 && _waiters.empty()) {
+
+        assert(_count == 0);
+
+        _owner = &m;    
+        _count++;
+
+      } else { // Otherwise, wait()
+        
+        _waiters.push_back(&m);
+
+        m.acquire();
+
+        {
+
+          Guard<FastLock, UnlockedScope> g2(g1);
+          state = m.wait();
+
+        }
+
+        m.release();
+        
+        // Remove from waiter list, regarless of weather release() is called or
+        // not. The monitor is sticky, so its possible a state 'stuck' from a
+        // previous operation and will leave the wait() w/o release() having
+        // been called.
+        List::iterator i = std::find(_waiters.begin(), _waiters.end(), &m);
+        if(i != _waiters.end())
+          _waiters.erase(i);
+
+        // If awoke due to a notify(), take ownership. 
+        switch(state) {
+          case Monitor::SIGNALED:
+          
+            assert(_owner == 0);
+            assert(_count == 0);
+
+            _owner = &m;
+            _count++;
+            
+            break;
+
+          case Monitor::INTERRUPTED:
+            throw Interrupted_Exception();
+            
+          default:
+            throw Synchronization_Exception();
+        } 
+            
+      }
+      
+    }
+
+  }
+
+  bool RecursiveMutexImpl::tryAcquire(unsigned long timeout) {
+  
+    // Get the monitor for the current thread
+    Monitor& m = ThreadImpl::current()->getMonitor();
+
+    Guard<FastLock> g1(_lock);
+  
+    // If there is an entry count and the current thread is 
+    // the owner, increment the count and continue.
+    if(_owner == &m)
+      _count++;
+
+    else {
+
+      // Acquire the lock if it is free and there are no waiting threads
+      if(_owner == 0 && _waiters.empty()) {
+
+        assert(_count == 0);
+
+        _owner = &m;
+        _count++;
+
+      } else { // Otherwise, wait()
+
+        _waiters.push_back(&m);
+
+        Monitor::STATE state = Monitor::TIMEDOUT;
+
+        // Don't bother waiting if the timeout is 0
+        if(timeout) {
+
+          m.acquire();
+
+          {
+          
+            Guard<FastLock, UnlockedScope> g2(g1);
+            state = m.wait(timeout);
+          
+          }
+
+          m.release();
+        
+        }
+
+        // Remove from waiter list, regarless of weather release() is called or
+        // not. The monitor is sticky, so its possible a state 'stuck' from a
+        // previous operation and will leave the wait() w/o release() having
+        // been called.
+        List::iterator i = std::find(_waiters.begin(), _waiters.end(), &m);
+        if(i != _waiters.end())
+          _waiters.erase(i);
+
+        // If awoke due to a notify(), take ownership. 
+        switch(state) {
+          case Monitor::SIGNALED:
+
+            assert(_count == 0);
+            assert(_owner == 0);
+
+            _owner = &m;
+            _count++;
+            
+            break;
+
+          case Monitor::INTERRUPTED:
+            throw Interrupted_Exception();
+          
+          case Monitor::TIMEDOUT:
+            return false;
+
+          default:
+            throw Synchronization_Exception();
+        } 
+            
+      }
+      
+    }
+
+    return true;
+
+  }
+
+  void RecursiveMutexImpl::release() {
+
+    // Get the monitor for the current thread
+    Monitor& m = ThreadImpl::current()->getMonitor();
+
+    Guard<FastLock> g1(_lock);
+
+    // Make sure the operation is valid
+    if(!(_owner == &m))
+      throw InvalidOp_Exception();
+
+    // Update the count, if it has reached 0, wake another waiter.
+    if(--_count == 0) {
+    
+      _owner = 0;
+
+      // Try to find a waiter with a backoff & retry scheme
+      for(;;) {
+
+        // Go through the list, attempt to notify() a waiter.
+        for(List::iterator i = _waiters.begin(); i != _waiters.end();) {
+        
+          // Try the monitor lock, if it cant be locked skip to the next waiter
+          Monitor* n = *i;
+          if(n->tryAcquire()) {
+           
+            // If notify() is not sucessful, it is because the wait() has already 
+            // been ended (killed/interrupted/notify'd)
+            bool woke = n->notify();
+            n->release();
+          
+            // Once notify() succeeds, return
+            if(woke)
+              return;
+          
+          } else ++i;
+        
+        }
+      
+        if(_waiters.empty())
+          return;
+
+        { // Backoff and try again
+
+          Guard<FastLock, UnlockedScope> g2(g1);
+          ThreadImpl::yield();
+
+        }
+
+      }
+
+    }
+  
+  }
+
+} // namespace ZThread
+
+
+
+