--- /dev/null
+++ xnu/xnu-792.2.4/iokit/Kernel/IOPMPowerStateQueue.cpp
@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2001-2002 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * The contents of this file constitute Original Code as defined in and
+ * are subject to the Apple Public Source License Version 1.1 (the
+ * "License").  You may not use this file except in compliance with the
+ * License.  Please obtain a copy of the License at
+ * http://www.apple.com/publicsource and read it before using this file.
+ *
+ * This Original Code and all software distributed under the License are
+ * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
+ * License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+ 
+#include "IOPMPowerStateQueue.h"
+#undef super
+#define super IOEventSource
+OSDefineMetaClassAndStructors(IOPMPowerStateQueue, IOEventSource);
+
+IOPMPowerStateQueue *IOPMPowerStateQueue::PMPowerStateQueue(OSObject *inOwner)
+{
+    IOPMPowerStateQueue     *me = new IOPMPowerStateQueue;
+
+    if(me && !me->init(inOwner, 0) )
+    {
+        me->release();
+        return NULL;
+    }
+
+    return me;
+}
+
+bool IOPMPowerStateQueue::init(OSObject *owner, Action action)
+{
+    if(!(super::init(owner, (IOEventSource::Action) action))) return false;
+
+    // Queue of powerstate changes
+    changes = NULL;
+
+    return true;
+}
+
+
+bool IOPMPowerStateQueue::unIdleOccurred(IOService *inTarget, unsigned long inState)
+{
+    PowerChangeEntry             *new_one = NULL;
+
+    new_one = (PowerChangeEntry *)IOMalloc(sizeof(PowerChangeEntry));
+    if(!new_one) return false;
+    
+    new_one->actionType = IOPMPowerStateQueue::kUnIdle;
+    new_one->state = inState;
+    new_one->target = inTarget;
+    
+    // Change to queue
+    OSEnqueueAtomic((void **)&changes, (void *)new_one, 0);
+    
+    signalWorkAvailable();
+
+    return true;
+}
+
+// checkForWork() is called in a gated context
+bool IOPMPowerStateQueue::checkForWork()
+{
+    PowerChangeEntry            *theNode;
+    int                         theState;
+    IOService                   *theTarget;
+    UInt16                      theAction;
+    
+    // Dequeue and process the state change request
+    if((theNode = (PowerChangeEntry *)OSDequeueAtomic((void **)&changes, 0)))
+    {
+        theState = theNode->state;
+        theTarget = theNode->target;
+        theAction = theNode->actionType;
+        IOFree((void *)theNode, sizeof(PowerChangeEntry));
+        
+        switch (theAction)
+        {
+            case kUnIdle:
+                theTarget->command_received(theState, 0, 0, 0);
+                break;
+        }
+    }
+
+    // Return true if there's more work to be done
+    if(changes) return true;
+    else return false;
+}