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28 
29 #ifndef _IOKIT_IOSERVICESTATENOTIFICATIONEVENTSOURCE_H
30 #define _IOKIT_IOSERVICESTATENOTIFICATIONEVENTSOURCE_H
31 
32 #include <libkern/c++/OSPtr.h>
33 #include <IOKit/IOEventSource.h>
34 
35 class IOService;
36 
37 
38 /*! @class IOServiceStateNotificationEventSource : public IOEventSource
39  *   @abstract Event source for IOService state notification delivery to work-loop based drivers.
40  *   @discussion For use with the IOService.iig IOService::StateNotification* APIs.
41  */
42 
43 class IOServiceStateNotificationEventSource : public IOEventSource
44 {
45 	OSDeclareDefaultStructors(IOServiceStateNotificationEventSource);
46 
47 public:
48 	typedef void (^ActionBlock)();
49 
50 protected:
51 	IOService                    * fStateNotification;
52 	IOStateNotificationListenerRef fListener;
53 	bool                           fEnable;
54 	bool                           fArmed;
55 
56 /*! @struct ExpansionData
57  *   @discussion This structure will be used to expand the capablilties of the IOWorkLoop in the future.
58  */
59 
60 /*! @var reserved
61  *   Reserved for future use.  (Internal use only)  */
62 	APPLE_KEXT_WSHADOW_PUSH;
63 	ExpansionData *reserved;
64 	APPLE_KEXT_WSHADOW_POP;
65 
66 /*! @function free
67  *   @abstract Sub-class implementation of free method, disconnects from the interrupt source. */
68 	virtual void free() APPLE_KEXT_OVERRIDE;
69 
70 /*! @function checkForWork
71  *   @abstract Pure Virtual member function used by IOWorkLoop for issueing a client calls.
72  *   @discussion This function called when the work-loop is ready to check for any work to do and then to call out the owner/action.
73  *   @result Return true if this function needs to be called again before all its outstanding events have been processed. */
74 	virtual bool checkForWork() APPLE_KEXT_OVERRIDE;
75 
76 /*! @function setWorkLoop
77  *   @abstract Sub-class implementation of setWorkLoop method. */
78 	virtual void setWorkLoop(IOWorkLoop *inWorkLoop) APPLE_KEXT_OVERRIDE;
79 
80 public:
81 
82 	/*!
83 	 * @brief       Create an IOServiceStateNotificationEventSource for notification of IOService state events sent by the StateNotificationSet() api.
84 	 * @param       service The object hosting state, typically returned by IOService::CopySystemStateNotificationService().
85 	 * @param       items Array of state item names to be notified about.
86 	 * @param       action Handler block to be invoked on the event source workloop when the notification fires.
87 	 * @return      IOServiceStateNotificationEventSource with +1 retain, or NULL on failure.
88 	 */
89 	static OSPtr<IOServiceStateNotificationEventSource>
90 	serviceStateNotificationEventSource(IOService *service,
91 	    OSArray * items,
92 	    ActionBlock action);
93 
94 /*! @function enable
95  *   @abstract Enable event source.
96  *   @discussion A subclass implementation is expected to respect the enabled
97  *  state when checkForWork is called.  Calling this function will cause the
98  *  work-loop to be signalled so that a checkForWork is performed. */
99 	virtual void enable() APPLE_KEXT_OVERRIDE;
100 
101 /*! @function disable
102  *   @abstract Disable event source.
103  *   @discussion A subclass implementation is expected to respect the enabled
104  *  state when checkForWork is called. */
105 	virtual void disable() APPLE_KEXT_OVERRIDE;
106 
107 private:
108 	OSMetaClassDeclareReservedUnused(IOServiceStateNotificationEventSource, 0);
109 	OSMetaClassDeclareReservedUnused(IOServiceStateNotificationEventSource, 1);
110 	OSMetaClassDeclareReservedUnused(IOServiceStateNotificationEventSource, 2);
111 	OSMetaClassDeclareReservedUnused(IOServiceStateNotificationEventSource, 3);
112 	OSMetaClassDeclareReservedUnused(IOServiceStateNotificationEventSource, 4);
113 	OSMetaClassDeclareReservedUnused(IOServiceStateNotificationEventSource, 5);
114 	OSMetaClassDeclareReservedUnused(IOServiceStateNotificationEventSource, 6);
115 	OSMetaClassDeclareReservedUnused(IOServiceStateNotificationEventSource, 7);
116 };
117 
118 #endif /* !_IOKIT_IOSERVICESTATENOTIFICATIONEVENTSOURCE_H */
119