/*
* Copyright (c) 2019-2019 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_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. 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
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* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
#ifndef _IOKIT_OSACTION_H
#define _IOKIT_OSACTION_H
#include <DriverKit/OSObject.iig>
typedef void (^OSActionCancelHandler)(void);
typedef void (^OSActionAbortedHandler)(void);
struct OSActionWaitToken;
class OSString;
/*!
* @class OSAction
*
* @abstract
* OSAction is an object that represents a callback to be be invoked.
*
* @discussion
* The callback is specified as a method and object pair.
* State associated with the callback may be allocated and stored for the creator of the object.
* Methods to allocate an OSAction instance are generated for each method defined in a class with
* a TYPE attribute. The generated methods are named CreateAction{name of method with type attribute}
* and have the following declaration:
*
* kern_return_t CreateActionNameOfMethod(size_t referenceSize, OSAction **action);
*
* referenceSize refers to the size of additional state structure available to the creator of the OSAction
* with GetReference. If successful, the generated method returns kIOReturnSuccess and a created OSAction
* through the 'action' parameter with a +1 retain count to be released by the caller. See IOReturn.h for
* error codes.
*/
class NATIVE KERNEL OSAction : public OSObject
{
public:
#if DRIVERKIT_PRIVATE
/*!
* @brief Create an instance of OSAction.
* @discussion Methods to allocate an OSAction instance are generated for each method defined in a class with
* a TYPE attribute, so there should not be any need to directly call OSAction::Create().
* @param target OSObject to receive the callback. This object will be retained until the OSAction is
* canceled or freed.
* @param targetmsgid Generated message ID for the target method.
* @param msgid Generated message ID for the method invoked by the receiver of the OSAction
* to generate the callback.
* @param referenceSize Size of additional state structure available to the creator of the OSAction
* with GetReference.
* @param action Created OSAction with +1 retain count to be released by the caller.
* @return kIOReturnSuccess on success. See IOReturn.h for error codes.
*/
static kern_return_t
Create(
OSObject * target,
uint64_t targetmsgid,
uint64_t msgid,
size_t referenceSize,
OSAction ** action) LOCAL;
static kern_return_t
CreateWithTypeName(
OSObject * target,
uint64_t targetmsgid,
uint64_t msgid,
size_t referenceSize,
OSString * typeName,
OSAction ** action) LOCAL;
#endif
virtual void
free() override;
/*!
* @brief Return a pointer to any state allocated by the OSAction creator.
* @discussion Reference data is allocated with zero initialized content. It may be set and retrieved later
* with this method.
* @return A pointer to storage for the owner. It will be NULL if referenceSize was zero, and NULL
* when called in a process other than the owner that is receiving the OSAction as a parameter.
*/
void *
GetReference() LOCALONLY;
/*!
* @brief Cancel all callbacks from the action.
* @discussion After cancellation, the action can only be freed. It cannot be reactivated.
* @param handler Handler block to be invoked after any callbacks have completed.
* @return kIOReturnSuccess on success. See IOReturn.h for error codes.
*/
kern_return_t
Cancel(OSActionCancelHandler handler) LOCALONLY;
/*!
* @brief Install a handler to be invoked when no other processes reference the action.
* @discussion When all tasks other than the creator release their references to the action,
* invoke the handler in the owner. A task exiting will always remove its references.
* @param handler Handler block to be invoked on no more references.
* @return kIOReturnSuccess on success. See IOReturn.h for error codes.
*/
kern_return_t
SetAbortedHandler(OSActionAbortedHandler handler) LOCALONLY;
/*!
* @brief Mark this OSAction to be waited for later with Wait().
* @discussion This call should be made before any possible invocation of the action.
* An OSAction instance only supports one waiter and WillWait() will return an error if already called.
* @param token Opaque value to be passed to a later call to Wait() and EndWait().
* @return kIOReturnSuccess on success. See IOReturn.h for error codes.
*/
kern_return_t
WillWait(OSActionWaitToken ** token) LOCALONLY;
/*!
* @brief Discard the OSActionWaitToken for the action.
* @discussion Free any resources needed to wait for the action allocated by WillWait().
* There should be no outstanding invocations of the action when EndWait is called,
* if necessary the action should be canceled before calling EndWait().
* @param token Opaque value to be passed from an earlier call to WillWait().
* @return kIOReturnSuccess on success. kIOReturnAborted if aborted or canceled.
kIOReturnTimeout if the deadline was passed. See IOReturn.h for error codes.
*/
kern_return_t
EndWait(
OSActionWaitToken * token) LOCALONLY;
/*!
* @brief Wait for the action to be invoked.
* @discussion The current thread is blocked until the action invocation has completed, the action canceled
or aborted, or the deadline passed.
* @param token Opaque value to be passed from an earlier call to WillWait().
* @param options Pass one of the kIOTimerClock* options to specify the timebase for the
* deadline, or zero for no timeout.
* @param deadline Pass the time the wait should timeout, or zero for no timeout.
* @return kIOReturnSuccess on success. kIOReturnAborted if aborted or canceled.
kIOReturnTimeout if the deadline was passed. See IOReturn.h for error codes.
*/
kern_return_t
Wait(
OSActionWaitToken * token,
uint64_t options,
uint64_t deadline) LOCALONLY;
virtual void
Aborted(void) LOCALHOST;
};
#endif /* ! _IOKIT_OSACTION_H */