/*
 * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The 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, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
Copyright (c) 1998 Apple Computer, Inc.  All rights reserved.

HISTORY
    1998-7-13	Godfrey van der Linden(gvdl)
        Created.
    1998-10-30	Godfrey van der Linden(gvdl)
        Converted to C++
    1999-9-22	Godfrey van der Linden(gvdl)
	Deprecated
]*/
#ifndef _IOKIT_IOCOMMANDQUEUE_H
#define _IOKIT_IOCOMMANDQUEUE_H

#include <IOKit/IOEventSource.h>




#warning IOCommandQueue has been deprecated in favour of IOCommandGate and will be going away before too long.





class IOCommandQueue;

typedef void (*IOCommandQueueAction)
    (OSObject *, void *field0, void *field1, void *field2, void *field3);

class IOCommandQueue : public IOEventSource
{
    OSDeclareDefaultStructors(IOCommandQueue)

protected:
    static const int kIOCQDefaultSize = 128;

    void *queue;
    IOLock *producerLock;
    semaphore_port_t producerSema;
    int producerIndex, consumerIndex;
    int size;

    virtual void free();

    virtual bool checkForWork();

public:
    static IOCommandQueue *commandQueue(OSObject *inOwner,
                                        IOCommandQueueAction inAction = 0,
                                        int inSize = kIOCQDefaultSize);
    virtual bool init(OSObject *inOwner,
                      IOCommandQueueAction inAction = 0,
                      int inSize = kIOCQDefaultSize);

    virtual kern_return_t enqueueCommand(bool gotoSleep = true,
                                         void *field0 = 0, void *field1 = 0,
                                         void *field2 = 0, void *field3 = 0);

    // WARNING:  This function can only be safely called from the appropriate
    // work loop context.  You should check IOWorkLoop::onThread is true.
    //
    // For each entry in the commandQueue call the target/action.
    // Lockout all new entries to the queue while iterating.
    // If the input fields are zero then the queue's owner/action will be used.
    virtual int performAndFlush(OSObject *target = 0,
                                IOCommandQueueAction inAction = 0);
};

#endif /* !_IOKIT_IOCOMMANDQUEUE_H */
