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

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_OSREFERENCE_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.  The rights granted to you under the 
 * License may not be used to create, or enable the creation or 
 * redistribution of, unlawful or unlicensed copies of an Apple operating 
 * system, or to circumvent, violate, or enable the circumvention or 
 * violation of, any terms of an Apple operating system software license 
 * agreement.
 *
 * 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_OSREFERENCE_HEADER_END@
 */

/*
 *
 *	Copyright (c) 2000 Apple Computer, Inc.  All rights reserved.
 *
 *	HISTORY
 *
 *	2001-01-17	gvdl	Re-implement on IOCommandGate::commandSleep
 *	11/13/2000	CJS	Created IOCommandPool class and implementation
 *
 */

/*!
 * @header IOCommandPool
 * @abstract
 * This header contains the IOCommandPool class definition.
 */

#ifndef _IOKIT_IO_COMMAND_POOL_H_
#define _IOKIT_IO_COMMAND_POOL_H_

/*
 * Kernel
 */

#if defined(KERNEL) && defined(__cplusplus)

#include <kern/kern_types.h>
#include <kern/queue.h>
#include <IOKit/IOCommand.h>
#include <IOKit/IOCommandGate.h>
#include <IOKit/IOService.h>
#include <IOKit/IOWorkLoop.h>

/*!
 * @class IOCommandPool
 * @abstract Manipulates a pool of commands which inherit from IOCommand.
 * @discussion
 * The IOCommandPool class is used to manipulate a pool of commands which
 * inherit from IOCommand. It includes a factory method to create a pool
 * of a certain size. Once the factory method is invoked, the semaphore
 * is set to zero. The caller must then put commands in the pool by creating
 * the command (via the controller's factory method or a memory allocation)
 * and calling the returnCommand method with the newly created command as its
 * argument.
 */

class IOCommandPool : public OSObject
{
	
    OSDeclareDefaultStructors(IOCommandPool)
    
    
protected:

    queue_head_t fQueueHead;	/* head of the queue of elements available */
    UInt32 fSleepers;		/* Count of threads sleeping on this pool */
    IOCommandGate *fSerializer;	/* command gate used for serializing pool access */

/*! @struct ExpansionData
    @discussion This structure will be used to expand the capablilties of the IOEventSource in the future.
    */    
    struct ExpansionData { };

/*! @var reserved
    Reserved for future use.  (Internal use only)  */
    ExpansionData *reserved;

    /*!
     * @const kIOCommandPoolDefaultSize
     * @abstract The default size of any command pool.
     * @discussion
     * kIOCommandPoolDefaultSize is the default size of any command pool.
     * The default size was determined to be the smallest size for which
     * a pool makes sense.
     */

    static const UInt32 kIOCommandPoolDefaultSize = 2;
    
    /*
     * Free all of this object's outstanding resources.
     */

    virtual void free(void);
    
    
public:

    /*!
     * @function initWithWorkLoop
     * @abstract Primary initializer for an IOCommandPool object.
     * @discussion Primary initializer for an IOCommandPool.
     * Should probably use IOCommandPool::withWorkLoop() as it is easier to use.
     * @param inWorkLoop
     * The workloop that this command pool should synchronize with.
     * @result Returns true if command pool was successfully initialized.
     */
    virtual bool initWithWorkLoop(IOWorkLoop *workLoop);

    /*!
     * @function withWorkLoop
     * @abstract Primary factory method for the IOCommandPool class
     * @discussion
     * The withWorkLoop method is what is known as a factory method. It creates
     * a new instance of an IOCommandPool and returns a pointer to that object.
     * @param inWorkLoop
     * The workloop that this command pool should synchronize with.
     * @result
     * Returns a pointer to an instance of IOCommandPool if successful,
     * otherwise NULL.
     */

    static IOCommandPool *withWorkLoop(IOWorkLoop *inWorkLoop);

    /*!
     * @function init
     * @abstract Should never be used, obsolete. See initWithWorkLoop.
     */
    virtual bool init(IOService *inOwner,
                      IOWorkLoop *inWorkLoop,
                      UInt32 inSize = kIOCommandPoolDefaultSize);

    /*!
     * @function withWorkLoop
     * @abstract Should never be used, obsolete. See IOCommandPool::withWorkLoop.
     */
    static IOCommandPool *commandPool(IOService *inOwner,
                                        IOWorkLoop *inWorkLoop,
                                        UInt32 inSize = kIOCommandPoolDefaultSize);
    
    
    /*!
     * @function getCommand
     * @discussion The getCommand method is used to get a pointer to an object of type IOCommand from the pool.
     * @param blockForCommand
     * If the caller would like to have its thread slept until a command is
     * available, it should pass true, else false.
     * @result
     * If the caller passes true in blockForCommand, getCommand guarantees that
     * the result will be a pointer to an IOCommand object from the pool. If
     * the caller passes false, s/he is responsible for checking whether a non-NULL
     * pointer was returned.
     */

    virtual IOCommand *getCommand(bool blockForCommand = true);
    
    /*!
     * @function returnCommand
     * @discussion
     * The returnCommand method is used to place an object of type IOCommand
     * into the pool, whether it be the first time, or the 1000th time.
     * @param commmand
     * The command to place in the pool.
     */
    
    virtual void returnCommand(IOCommand *command);
    
protected:
    
    /*!
     * @function gatedGetCommand
     * @discussion
     * The gatedGetCommand method is used to serialize the extraction of a 
     * command from the pool behind a command gate, runAction-ed by getCommand.
     * @param vCommand
     * A pointer to a pointer to an IOCommand object where the returned
     * command will be stored.
     * @param vBlock
     * A bool that indicates whether to block the request until a command
     * becomes available.
     * @result
     * Returns kIOReturnNoResources if no command is available and the client
     * doesn't wish to block until one does become available.
     * kIOReturnSuccess if the vCommand argument is valid.
     */
    virtual IOReturn gatedGetCommand(IOCommand **command, bool blockForCommand);
    
    /*!
     * @function gatedReturnCommand
     * @discussion
     * The gatedReturnCommand method is used to serialize the return of a 
     * command to the pool behind a command gate, runAction-ed by returnCommand.
     * @param vCommand
     * A pointer to the IOCommand object to be returned to the pool.
     * @result
     * Always returns kIOReturnSuccess if the vCommand argument is valid.
     */
    virtual IOReturn gatedReturnCommand(IOCommand *command);

private:
    OSMetaClassDeclareReservedUnused(IOCommandPool, 0);
    OSMetaClassDeclareReservedUnused(IOCommandPool, 1);
    OSMetaClassDeclareReservedUnused(IOCommandPool, 2);
    OSMetaClassDeclareReservedUnused(IOCommandPool, 3);
    OSMetaClassDeclareReservedUnused(IOCommandPool, 4);
    OSMetaClassDeclareReservedUnused(IOCommandPool, 5);
    OSMetaClassDeclareReservedUnused(IOCommandPool, 6);
    OSMetaClassDeclareReservedUnused(IOCommandPool, 7);
};

#endif	/* defined(KERNEL) && defined(__cplusplus) */

#endif	/* _IOKIT_IO_COMMAND_POOL_H_ */
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
	3	*
8ad349bb	4	* @APPLE_LICENSE_OSREFERENCE_HEADER_START@
1c79356b	5	*
8ad349bb A	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the
	10	* License may not be used to create, or enable the creation or
	11	* redistribution of, unlawful or unlicensed copies of an Apple operating
	12	* system, or to circumvent, violate, or enable the circumvention or
	13	* violation of, any terms of an Apple operating system software license
	14	* agreement.
	15	*
	16	* Please obtain a copy of the License at
	17	* http://www.opensource.apple.com/apsl/ and read it before using this
	18	* file.
	19	*
	20	* The Original Code and all software distributed under the License are
	21	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	22	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	23	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	24	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	25	* Please see the License for the specific language governing rights and
	26	* limitations under the License.
	27	*
	28	* @APPLE_LICENSE_OSREFERENCE_HEADER_END@
1c79356b A	29	*/
	30
	31	/*
	32	*
	33	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
	34	*
	35	* HISTORY
	36	*
	37	* 2001-01-17 gvdl Re-implement on IOCommandGate::commandSleep
	38	* 11/13/2000 CJS Created IOCommandPool class and implementation
	39	*
	40	*/
	41
	42	/*!
	43	* @header IOCommandPool
	44	* @abstract
	45	* This header contains the IOCommandPool class definition.
	46	*/
	47
	48	#ifndef _IOKIT_IO_COMMAND_POOL_H_
	49	#define _IOKIT_IO_COMMAND_POOL_H_
	50
	51	/*
	52	* Kernel
	53	*/
	54
	55	#if defined(KERNEL) && defined(__cplusplus)
	56
	57	#include <kern/kern_types.h>
	58	#include <kern/queue.h>
	59	#include <IOKit/IOCommand.h>
	60	#include <IOKit/IOCommandGate.h>
	61	#include <IOKit/IOService.h>
	62	#include <IOKit/IOWorkLoop.h>
	63
	64	/*!
	65	* @class IOCommandPool
91447636	66	* @abstract Manipulates a pool of commands which inherit from IOCommand.
1c79356b A	67	* @discussion
	68	* The IOCommandPool class is used to manipulate a pool of commands which
	69	* inherit from IOCommand. It includes a factory method to create a pool
	70	* of a certain size. Once the factory method is invoked, the semaphore
	71	* is set to zero. The caller must then put commands in the pool by creating
	72	* the command (via the controller's factory method or a memory allocation)
	73	* and calling the returnCommand method with the newly created command as its
	74	* argument.
	75	*/
	76
	77	class IOCommandPool : public OSObject
	78	{
	79
	80	OSDeclareDefaultStructors(IOCommandPool)
	81
	82
	83	protected:
	84
	85	queue_head_t fQueueHead; /* head of the queue of elements available */
	86	UInt32 fSleepers; /* Count of threads sleeping on this pool */
	87	IOCommandGate fSerializer; / command gate used for serializing pool access */
	88
	89	/*! @struct ExpansionData
	90	@discussion This structure will be used to expand the capablilties of the IOEventSource in the future.
	91	*/
	92	struct ExpansionData { };
	93
	94	/*! @var reserved
	95	Reserved for future use. (Internal use only) */
	96	ExpansionData *reserved;
	97
	98	/*!
91447636 A	99	* @const kIOCommandPoolDefaultSize
91447636 A	100	* @abstract The default size of any command pool.
1c79356b A	101	* @discussion
	102	* kIOCommandPoolDefaultSize is the default size of any command pool.
	103	* The default size was determined to be the smallest size for which
	104	* a pool makes sense.
	105	*/
	106
	107	static const UInt32 kIOCommandPoolDefaultSize = 2;
	108
	109	/*
	110	* Free all of this object's outstanding resources.
	111	*/
	112
	113	virtual void free(void);
	114
	115
	116	public:
	117
	118	/*!
	119	* @function initWithWorkLoop
91447636 A	120	* @abstract Primary initializer for an IOCommandPool object.
91447636 A	121	* @discussion Primary initializer for an IOCommandPool.
1c79356b A	122	* Should probably use IOCommandPool::withWorkLoop() as it is easier to use.
1c79356b A	123	* @param inWorkLoop
91447636 A	124	* The workloop that this command pool should synchronize with.
91447636 A	125	* @result Returns true if command pool was successfully initialized.
1c79356b A	126	*/
	127	virtual bool initWithWorkLoop(IOWorkLoop *workLoop);
	128
	129	/*!
	130	* @function withWorkLoop
	131	* @abstract Primary factory method for the IOCommandPool class
	132	* @discussion
	133	* The withWorkLoop method is what is known as a factory method. It creates
	134	* a new instance of an IOCommandPool and returns a pointer to that object.
	135	* @param inWorkLoop
91447636	136	* The workloop that this command pool should synchronize with.
1c79356b A	137	* @result
	138	* Returns a pointer to an instance of IOCommandPool if successful,
	139	* otherwise NULL.
	140	*/
	141
	142	static IOCommandPool withWorkLoop(IOWorkLoop inWorkLoop);
	143
	144	/*!
	145	* @function init
91447636	146	* @abstract Should never be used, obsolete. See initWithWorkLoop.
1c79356b A	147	*/
	148	virtual bool init(IOService *inOwner,
	149	IOWorkLoop *inWorkLoop,
	150	UInt32 inSize = kIOCommandPoolDefaultSize);
	151
	152	/*!
	153	* @function withWorkLoop
91447636	154	* @abstract Should never be used, obsolete. See IOCommandPool::withWorkLoop.
1c79356b A	155	*/
	156	static IOCommandPool commandPool(IOService inOwner,
	157	IOWorkLoop *inWorkLoop,
	158	UInt32 inSize = kIOCommandPoolDefaultSize);
	159
	160
	161	/*!
	162	* @function getCommand
91447636	163	* @discussion The getCommand method is used to get a pointer to an object of type IOCommand from the pool.
1c79356b A	164	* @param blockForCommand
1c79356b A	165	* If the caller would like to have its thread slept until a command is
91447636	166	* available, it should pass true, else false.
1c79356b A	167	* @result
	168	* If the caller passes true in blockForCommand, getCommand guarantees that
	169	* the result will be a pointer to an IOCommand object from the pool. If
	170	* the caller passes false, s/he is responsible for checking whether a non-NULL
	171	* pointer was returned.
	172	*/
	173
	174	virtual IOCommand *getCommand(bool blockForCommand = true);
	175
	176	/*!
	177	* @function returnCommand
	178	* @discussion
	179	* The returnCommand method is used to place an object of type IOCommand
	180	* into the pool, whether it be the first time, or the 1000th time.
	181	* @param commmand
	182	* The command to place in the pool.
	183	*/
	184
	185	virtual void returnCommand(IOCommand *command);
	186
	187	protected:
	188
	189	/*!
	190	* @function gatedGetCommand
	191	* @discussion
	192	* The gatedGetCommand method is used to serialize the extraction of a
91447636	193	* command from the pool behind a command gate, runAction-ed by getCommand.
1c79356b A	194	* @param vCommand
1c79356b A	195	* A pointer to a pointer to an IOCommand object where the returned
91447636	196	* command will be stored.
1c79356b A	197	* @param vBlock
	198	* A bool that indicates whether to block the request until a command
	199	* becomes available.
	200	* @result
	201	* Returns kIOReturnNoResources if no command is available and the client
91447636	202	* doesn't wish to block until one does become available.
1c79356b A	203	* kIOReturnSuccess if the vCommand argument is valid.
	204	*/
	205	virtual IOReturn gatedGetCommand(IOCommand **command, bool blockForCommand);
	206
	207	/*!
	208	* @function gatedReturnCommand
	209	* @discussion
	210	* The gatedReturnCommand method is used to serialize the return of a
91447636	211	* command to the pool behind a command gate, runAction-ed by returnCommand.
1c79356b A	212	* @param vCommand
	213	* A pointer to the IOCommand object to be returned to the pool.
	214	* @result
	215	* Always returns kIOReturnSuccess if the vCommand argument is valid.
	216	*/
	217	virtual IOReturn gatedReturnCommand(IOCommand *command);
	218
	219	private:
	220	OSMetaClassDeclareReservedUnused(IOCommandPool, 0);
	221	OSMetaClassDeclareReservedUnused(IOCommandPool, 1);
	222	OSMetaClassDeclareReservedUnused(IOCommandPool, 2);
	223	OSMetaClassDeclareReservedUnused(IOCommandPool, 3);
	224	OSMetaClassDeclareReservedUnused(IOCommandPool, 4);
	225	OSMetaClassDeclareReservedUnused(IOCommandPool, 5);
	226	OSMetaClassDeclareReservedUnused(IOCommandPool, 6);
	227	OSMetaClassDeclareReservedUnused(IOCommandPool, 7);
	228	};
	229
	230	#endif /* defined(KERNEL) && defined(__cplusplus) */
	231
	232	#endif /* _IOKIT_IO_COMMAND_POOL_H_ */