1 files changed, 109 insertions, 0 deletions
diff --git a/dep/src/zthread/PriorityInheritanceMutex.cxx b/dep/src/zthread/PriorityInheritanceMutex.cxx
new file mode 100644
index 00000000000..108e4a74370
--- /dev/null
+++ b/dep/src/zthread/PriorityInheritanceMutex.cxx
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+/*
+ * 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 "zthread/PriorityInheritanceMutex.h"
+#include "MutexImpl.h"
+#include "ThreadOps.h"
+
+
+namespace ZThread {
+
+  class InheritPriorityBehavior : public NullBehavior {
+  
+    ThreadImpl* owner;
+    Priority p;
+
+  protected:
+
+    // Temporarily raise the effective priority of the owner 
+    inline void waiterArrived(ThreadImpl* impl) {  
+    
+      Priority q = impl->getPriority();
+      if((int)q > (int)p) {
+
+        ThreadOps::setPriority(impl, p);
+        p = q;
+      
+      }
+
+    }
+
+
+    // Note the owners priority
+    inline void ownerAcquired(ThreadImpl* impl) {  
+
+      p = impl->getPriority();
+      owner = impl;
+
+    }
+
+    // Restore its original priority
+    inline void ownerReleased(ThreadImpl* impl) {  
+
+      if(p > owner->getPriority())
+        ThreadOps::setPriority(impl, impl->getPriority());
+
+    }
+
+  };
+
+  class PriorityInheritanceMutexImpl : 
+    public MutexImpl<priority_list, InheritPriorityBehavior> { };
+
+  PriorityInheritanceMutex::PriorityInheritanceMutex() {
+  
+    _impl = new PriorityInheritanceMutexImpl();
+  
+  }
+
+  PriorityInheritanceMutex::~PriorityInheritanceMutex() {
+
+    if(_impl != 0) 
+      delete _impl;
+
+  }
+
+  // P
+  void PriorityInheritanceMutex::acquire() {
+
+    _impl->acquire(); 
+
+  }
+
+
+  // P
+  bool PriorityInheritanceMutex::tryAcquire(unsigned long ms) {
+
+    return _impl->tryAcquire(ms); 
+
+  }
+
+  // V
+  void PriorityInheritanceMutex::release() {
+
+    _impl->release(); 
+
+  }
+
+
+} // namespace ZThread
+