xnu-2422.115.4.tar.gz

[apple/xnu.git] / iokit / IOKit / IOSharedDataQueue.h

diff --git a/iokit/IOKit/IOSharedDataQueue.h b/iokit/IOKit/IOSharedDataQueue.h
index fdfa1d6733eec388c4d9cb390f52b4b7b4ac7822..a31cfc965bbace9680f1e5b06ee3a4c911d5290b 100644 (file)
--- a/iokit/IOKit/IOSharedDataQueue.h
+++ b/iokit/IOKit/IOSharedDataQueue.h
@@ -53,6 +53,7 @@ class IOSharedDataQueue : public IODataQueue
     OSDeclareDefaultStructors(IOSharedDataQueue)
 
     struct ExpansionData { 
+        UInt32 queueSize;
     };
     /*! @var reserved
         Reserved for future use.  (Internal use only)  */
@@ -61,6 +62,9 @@ class IOSharedDataQueue : public IODataQueue
 protected:
     virtual void free();
 
+    UInt32 getQueueSize();
+    Boolean setQueueSize(UInt32 size);
+
 public:
     /*!
      * @function withCapacity
@@ -116,6 +120,16 @@ public:
      */
     virtual Boolean dequeue(void *data, UInt32 *dataSize);
 
+    /*!
+     * @function enqueue
+     * @abstract Enqueues a new entry on the queue.
+     * @discussion This method adds a new data entry of dataSize to the queue.  It sets the size parameter of the entry pointed to by the tail value and copies the memory pointed to by the data parameter in place in the queue.  Once that is done, it moves the tail to the next available location.  When attempting to add a new entry towards the end of the queue and there isn't enough space at the end, it wraps back to the beginning.<br>  If the queue is empty when a new entry is added, sendDataAvailableNotification() is called to send a message to the user process that data is now available.
+     * @param data Pointer to the data to be added to the queue.
+     * @param dataSize Size of the data pointed to by data.
+     * @result Returns true on success and false on failure.  Typically failure means that the queue is full.
+     */
+    virtual Boolean enqueue(void *data, UInt32 dataSize);
+
     OSMetaClassDeclareReservedUnused(IOSharedDataQueue, 0);
     OSMetaClassDeclareReservedUnused(IOSharedDataQueue, 1);
     OSMetaClassDeclareReservedUnused(IOSharedDataQueue, 2);