/*
- * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 1998-2009 Apple Inc. All rights reserved.
*
- * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
+ * @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
+ * 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@
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/*[
1999-8-10 Godfrey van der Linden(gvdl)
actually a lie but the work-loop single threaded semantic is maintained for this
event source. Using the work-loop gate rather than execution by the workloop.
The command gate tests for a potential self dead lock by checking if the
-runCommand request is made from the work-loop's thread, it doens't check for a
+runCommand request is made from the work-loop's thread, it doesn't check for a
mutual dead lock though where a pair of work loop's dead lock each other.
<br><br>
The IOCommandGate is a lighter weight version of the IOCommandQueue and
queue internal to the device or the device's family. Otherwise if the hardware
is inactive then this request can be acted upon immediately.
<br><br>
- CAUTION: The runAction and runCommand functions can not be called from an interrupt context.
+ CAUTION: The runAction, runCommand, and attemptCommand functions cannot be called from an interrupt context.
*/
class IOCommandGate : public IOEventSource
void *arg2, void *arg3);
protected:
-/*!
- @function checkForWork
- @abstract Not used, $link IOEventSource::checkForWork(). */
- virtual bool checkForWork();
/*! @struct ExpansionData
@discussion This structure will be used to expand the capablilties of the IOWorkLoop in the future.
@result True if inherited classes initialise successfully. */
virtual bool init(OSObject *owner, Action action = 0);
+ // Superclass overrides
+ virtual void free();
+ virtual void setWorkLoop(IOWorkLoop *inWorkLoop);
+
/*! @function runCommand
@abstract Single thread a command with the target work-loop.
@discussion Client function that causes the current action to be called in
gates can cause direct or indirect re-entrancy. When the executing on a
client's thread runCommand will sleep until the work-loop's gate opens for
execution of client actions, the action is single threaded against all other
-work-loop event sources.
+work-loop event sources. If the command is disabled the attempt to run a command will be stalled until enable is called.
@param arg0 Parameter for action of command gate, defaults to 0.
@param arg1 Parameter for action of command gate, defaults to 0.
@param arg2 Parameter for action of command gate, defaults to 0.
@param arg3 Parameter for action of command gate, defaults to 0.
- @result kIOReturnSuccess if successful. kIOReturnNotPermitted if this
-event source is currently disabled, kIOReturnNoResources if no action available.
+ @result kIOReturnSuccess if successful. kIOReturnAborted if a disabled command gate is free()ed before being reenabled, kIOReturnNoResources if no action available.
*/
virtual IOReturn runCommand(void *arg0 = 0, void *arg1 = 0,
void *arg2 = 0, void *arg3 = 0);
gates can cause direct or indirect re-entrancy. When the executing on a
client's thread runAction will sleep until the work-loop's gate opens for
execution of client actions, the action is single threaded against all other
-work-loop event sources.
+work-loop event sources. If the command is disabled the attempt to run a command will be stalled until enable is called.
@param action Pointer to function to be executed in work-loop context.
@param arg0 Parameter for action parameter, defaults to 0.
@param arg1 Parameter for action parameter, defaults to 0.
@param arg2 Parameter for action parameter, defaults to 0.
@param arg3 Parameter for action parameter, defaults to 0.
- @result kIOReturnSuccess if successful. kIOReturnBadArgument if action is not defined, kIOReturnNotPermitted if this event source is currently disabled.
+ @result kIOReturnSuccess if successful. kIOReturnBadArgument if action is not defined, kIOReturnAborted if a disabled command gate is free()ed before being reenabled.
*/
virtual IOReturn runAction(Action action,
void *arg0 = 0, void *arg1 = 0,
/*! @function attemptCommand
@abstract Single thread a command with the target work-loop.
@discussion Client function that causes the current action to be called in
-a single threaded manner. Beware the work-loop's gate is recursive and command
-gates can cause direct or indirect re-entrancy. When the executing on a
-client's thread attemptCommand will fail if the work-loop's gate is open.
+a single threaded manner. When the executing on a client's thread attemptCommand will fail if the work-loop's gate is closed.
@param arg0 Parameter for action of command gate, defaults to 0.
@param arg1 Parameter for action of command gate, defaults to 0.
@param arg2 Parameter for action of command gate, defaults to 0.
@discussion Client function that causes the given action to be called in
a single threaded manner. Beware the work-loop's gate is recursive and command
gates can cause direct or indirect re-entrancy. When the executing on a
-client's thread attemptCommand will fail if the work-loop's gate is open.
+client's thread attemptCommand will fail if the work-loop's gate is closed.
@param action Pointer to function to be executed in work-loop context.
@param arg0 Parameter for action parameter, defaults to 0.
@param arg1 Parameter for action parameter, defaults to 0.
/*! @function commandSleep
@abstract Put a thread that is currently holding the command gate to sleep.
- @discussion Put a thread to sleep waiting for an event but release the gate first. If the event occurs then the commandGate is closed before the returns.
+ @discussion Put a thread to sleep waiting for an event but release the gate first. If the event occurs then the commandGate is closed before the function returns.
@param event Pointer to an address.
- @param interruptible THREAD_UNINT, THREAD_INTERRUPTIBLE or THREAD_ABORTSAFE, defaults to THREAD_ABORTSAFE.
- @result THREAD_AWAKENED - normal wakeup, THREAD_TIMED_OUT - timeout expired, THREAD_INTERRUPTED - interrupted by clear_wait, THREAD_RESTART - restart operation entirely, kIOReturnNotPermitted if the calling thread does not hold the command gate. */
+ @param interruptible THREAD_UNINT, THREAD_INTERRUPTIBLE or THREAD_ABORTSAFE. THREAD_UNINT specifies that the sleep cannot be interrupted by a signal. THREAD_INTERRUPTIBLE specifies that the sleep may be interrupted by a "kill -9" signal. THREAD_ABORTSAFE (the default value) specifies that the sleep may be interrupted by any user signal.
+ @result THREAD_AWAKENED - normal wakeup, THREAD_TIMED_OUT - timeout expired, THREAD_INTERRUPTED - interrupted, THREAD_RESTART - restart operation entirely, kIOReturnNotPermitted if the calling thread does not hold the command gate. */
virtual IOReturn commandSleep(void *event,
UInt32 interruptible = THREAD_ABORTSAFE);
@param onlyOneThread true to only wake up at most one thread, false otherwise. */
virtual void commandWakeup(void *event, bool oneThread = false);
+/*! @function disable
+ @abstract Disable the command gate
+ @discussion When a command gate is disabled all future calls to runAction and runCommand will stall until the gate is enable()d later. This can be used to block client threads when a system sleep is requested. The IOWorkLoop thread itself will never stall, even when making runAction/runCommand calls. This call must be made from a gated context, to clear potential race conditions. */
+ virtual void disable();
+
+/*! @function enable
+ @abstract Enable command gate, this will unblock any blocked Commands and Actions.
+ @discussion Enable the command gate. The attemptAction/attemptCommand calls will now be enabled and can succeeed. Stalled runCommand/runAction calls will be woken up. */
+ virtual void enable();
+
+/*! @function commandSleep
+ @abstract Put a thread that is currently holding the command gate to sleep.
+ @discussion Put a thread to sleep waiting for an event but release the gate first. If the event occurs or timeout occurs then the commandGate is closed before the function returns.
+ @param event Pointer to an address.
+ @param deadline Clock deadline to timeout the sleep.
+ @param interruptible THREAD_UNINT, THREAD_INTERRUPTIBLE or THREAD_ABORTSAFE. THREAD_UNINT specifies that the sleep cannot be interrupted by a signal. THREAD_INTERRUPTIBLE specifies that the sleep may be interrupted by a "kill -9" signal. THREAD_ABORTSAFE specifies that the sleep may be interrupted by any user signal.
+ @result THREAD_AWAKENED - normal wakeup, THREAD_TIMED_OUT - timeout expired, THREAD_INTERRUPTED - interrupted, THREAD_RESTART - restart operation entirely, kIOReturnNotPermitted if the calling thread does not hold the command gate. */
+ virtual IOReturn commandSleep(void *event,
+ AbsoluteTime deadline,
+ UInt32 interruptible);
+
private:
+#if __LP64__
OSMetaClassDeclareReservedUnused(IOCommandGate, 0);
+#else
+ OSMetaClassDeclareReservedUsed(IOCommandGate, 0);
+#endif
OSMetaClassDeclareReservedUnused(IOCommandGate, 1);
OSMetaClassDeclareReservedUnused(IOCommandGate, 2);
OSMetaClassDeclareReservedUnused(IOCommandGate, 3);
projects / apple / xnu.git / blobdiff