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iokit/Kernel/IOCommandGate.cpp xnu-12377.121.6 xnu-344
--- xnu/xnu-12377.121.6/iokit/Kernel/IOCommandGate.cpp
+++ xnu/xnu-344/iokit/Kernel/IOCommandGate.cpp
@@ -1,50 +1,33 @@
 /*
- * Copyright (c) 1998-2000, 2009-2010 Apple Inc. All rights reserved.
+ * Copyright (c) 1998-2000 Apple Computer, 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
+ * @APPLE_LICENSE_HEADER_START@
+ * 
+ * The contents of this file constitute Original Code as defined in and
+ * are subject to the Apple Public Source License Version 1.1 (the
+ * "License").  You may not use this file except in compliance with the
+ * License.  Please obtain a copy of the License at
+ * http://www.apple.com/publicsource and read it before using this file.
+ * 
+ * This 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_OSREFERENCE_LICENSE_HEADER_END@
+ * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
+ * License for the specific language governing rights and limitations
+ * under the License.
+ * 
+ * @APPLE_LICENSE_HEADER_END@
  */
-
-#define IOKIT_ENABLE_SHARED_PTR
-
-#include <libkern/OSDebug.h>
-#include <libkern/c++/OSSharedPtr.h>
-
 #include <IOKit/IOCommandGate.h>
 #include <IOKit/IOWorkLoop.h>
 #include <IOKit/IOReturn.h>
 #include <IOKit/IOTimeStamp.h>
-#include <IOKit/IOKitDebug.h>
 
 #define super IOEventSource
 
-OSDefineMetaClassAndStructorsWithZone(IOCommandGate, IOEventSource, ZC_NONE)
-#if __LP64__
+OSDefineMetaClassAndStructors(IOCommandGate, IOEventSource)
 OSMetaClassDefineReservedUnused(IOCommandGate, 0);
-#else
-OSMetaClassDefineReservedUsedX86(IOCommandGate, 0);
-#endif
 OSMetaClassDefineReservedUnused(IOCommandGate, 1);
 OSMetaClassDefineReservedUnused(IOCommandGate, 2);
 OSMetaClassDefineReservedUnused(IOCommandGate, 3);
@@ -53,288 +36,132 @@
 OSMetaClassDefineReservedUnused(IOCommandGate, 6);
 OSMetaClassDefineReservedUnused(IOCommandGate, 7);
 
-#if IOKITSTATS
+bool IOCommandGate::checkForWork() { return false; }
 
-#define IOStatisticsInitializeCounter() \
-do { \
-	IOStatistics::setCounterType(IOEventSource::reserved->counter, kIOStatisticsCommandGateCounter); \
-} while (0)
-
-#define IOStatisticsActionCall() \
-do { \
-	IOStatistics::countCommandGateActionCall(IOEventSource::reserved->counter); \
-} while (0)
-
-#else
-
-#define IOStatisticsInitializeCounter()
-#define IOStatisticsActionCall()
-
-#endif /* IOKITSTATS */
-
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wcast-function-type"
-
-bool
-IOCommandGate::init(OSObject *inOwner, Action inAction)
+bool IOCommandGate::init(OSObject *inOwner, Action inAction = 0)
 {
-	bool res = super::init(inOwner, (IOEventSource::Action) inAction);
-	if (res) {
-		IOStatisticsInitializeCounter();
-	}
-
-	return res;
+    return super::init(inOwner, (IOEventSource::Action) inAction);
 }
 
-OSSharedPtr<IOCommandGate>
-IOCommandGate::commandGate(OSObject *inOwner, Action inAction)
+IOCommandGate *
+IOCommandGate::commandGate(OSObject *inOwner, Action inAction = 0)
 {
-	OSSharedPtr<IOCommandGate> me = OSMakeShared<IOCommandGate>();
+    IOCommandGate *me = new IOCommandGate;
 
-	if (me && !me->init(inOwner, inAction)) {
-		return nullptr;
-	}
+    if (me && !me->init(inOwner, inAction)) {
+        me->free();
+        return 0;
+    }
 
-	return me;
+    return me;
 }
 
-/* virtual */ void
-IOCommandGate::disable()
+IOReturn IOCommandGate::runCommand(void *arg0 = 0, void *arg1 = 0,
+                                   void *arg2 = 0, void *arg3 = 0)
 {
-	if (workLoop && !workLoop->inGate()) {
-		OSReportWithBacktrace("IOCommandGate::disable() called when not gated");
-	}
+    IOReturn res;
 
-	super::disable();
+    if (!enabled)
+        return kIOReturnNotPermitted;
+
+    if (!action)
+        return kIOReturnNoResources;
+
+    // closeGate is recursive so don't worry if we already hold the lock.
+    IOTimeStampConstant(IODBG_CMDQ(IOCMDQ_ACTION),
+			(unsigned int) action, (unsigned int) owner);
+
+    closeGate();
+    res = (*(Action) action)(owner, arg0, arg1, arg2, arg3);
+    openGate();
+
+    return res;
 }
 
-/* virtual */ void
-IOCommandGate::enable()
+IOReturn IOCommandGate::runAction(Action inAction,
+                                  void *arg0 = 0, void *arg1 = 0,
+                                  void *arg2 = 0, void *arg3 = 0)
 {
-	if (workLoop) {
-		closeGate();
-		super::enable();
-		wakeupGate(&enabled, /* oneThread */ false); // Unblock sleeping threads
-		openGate();
-	}
+    IOReturn res;
+
+    if (!enabled)
+        return kIOReturnNotPermitted;
+
+    if (!inAction)
+        return kIOReturnBadArgument;
+
+    IOTimeStampConstant(IODBG_CMDQ(IOCMDQ_ACTION),
+			(unsigned int) inAction, (unsigned int) owner);
+
+    // closeGate is recursive so don't worry if we already hold the lock.
+    closeGate();
+    res = (*inAction)(owner, arg0, arg1, arg2, arg3);
+    openGate();
+
+    return res;
 }
 
-/* virtual */ void
-IOCommandGate::free()
+IOReturn IOCommandGate::attemptCommand(void *arg0 = 0, void *arg1 = 0,
+                                       void *arg2 = 0, void *arg3 = 0)
 {
-	if (workLoop) {
-		setWorkLoop(NULL);
-	}
-	super::free();
+    IOReturn res;
+
+    if (!enabled)
+        return kIOReturnNotPermitted;
+
+    if (!action)
+        return kIOReturnNoResources;
+
+    // Try to hold the lock if can't get return immediately.
+    if (!tryCloseGate())
+        return kIOReturnCannotLock;
+
+    // closeGate is recursive so don't worry if we already hold the lock.
+    IOTimeStampConstant(IODBG_CMDQ(IOCMDQ_ACTION),
+			(unsigned int) action, (unsigned int) owner);
+
+    res = (*(Action) action)(owner, arg0, arg1, arg2, arg3);
+    openGate();
+
+    return res;
 }
 
-enum{
-	kSleepersRemoved     = 0x00000001,
-	kSleepersWaitEnabled = 0x00000002,
-	kSleepersActions     = 0x00000100,
-	kSleepersActionsMask = 0xffffff00,
-};
+IOReturn IOCommandGate::attemptAction(Action inAction,
+                                      void *arg0 = 0, void *arg1 = 0,
+                                      void *arg2 = 0, void *arg3 = 0)
+{
+    IOReturn res;
 
-/* virtual */ void
-IOCommandGate::setWorkLoop(IOWorkLoop *inWorkLoop)
-{
-	IOWorkLoop * wl;
-	uintptr_t  * sleepersP = (uintptr_t *) &reserved;
-	bool         defer;
+    if (!enabled)
+        return kIOReturnNotPermitted;
 
-	if (!inWorkLoop && (wl = workLoop)) {           // tearing down
-		wl->closeGate();
-		*sleepersP |= kSleepersRemoved;
-		while (*sleepersP & kSleepersWaitEnabled) {
-			thread_wakeup_with_result(&enabled, THREAD_INTERRUPTED);
-			sleepGate(sleepersP, THREAD_UNINT);
-		}
-		*sleepersP &= ~kSleepersWaitEnabled;
-		defer = (0 != (kSleepersActionsMask & *sleepersP));
-		if (!defer) {
-			super::setWorkLoop(NULL);
-			*sleepersP &= ~kSleepersRemoved;
-		}
-		wl->openGate();
-		return;
-	}
+    if (!inAction)
+        return kIOReturnBadArgument;
 
-	super::setWorkLoop(inWorkLoop);
+    // Try to close the gate if can't get return immediately.
+    if (!tryCloseGate())
+        return kIOReturnCannotLock;
+
+    IOTimeStampConstant(IODBG_CMDQ(IOCMDQ_ACTION),
+			(unsigned int) inAction, (unsigned int) owner);
+
+    res = (*inAction)(owner, arg0, arg1, arg2, arg3);
+    openGate();
+
+    return res;
 }
 
-IOReturn
-IOCommandGate::runCommand(void *arg0, void *arg1,
-    void *arg2, void *arg3)
+IOReturn IOCommandGate::commandSleep(void *event, UInt32 interruptible)
 {
-	return runAction((Action) action, arg0, arg1, arg2, arg3);
+    IOReturn ret;
+
+    if (!workLoop->inGate())
+        return kIOReturnNotPermitted;
+
+    return sleepGate(event, interruptible);
 }
 
-IOReturn
-IOCommandGate::attemptCommand(void *arg0, void *arg1,
-    void *arg2, void *arg3)
+void IOCommandGate::commandWakeup(void *event, bool oneThread)
 {
-	return attemptAction((Action) action, arg0, arg1, arg2, arg3);
+    wakeupGate(event, oneThread);
 }
-
-#pragma clang diagnostic pop
-
-static IOReturn
-IOCommandGateActionToBlock(OSObject *owner,
-    void *arg0, void *arg1,
-    void *arg2, void *arg3)
-{
-	return ((IOEventSource::ActionBlock) arg0)();
-}
-
-IOReturn
-IOCommandGate::runActionBlock(ActionBlock _action)
-{
-	return runAction(&IOCommandGateActionToBlock, _action);
-}
-
-IOReturn
-IOCommandGate::runAction(Action inAction,
-    void *arg0, void *arg1,
-    void *arg2, void *arg3)
-{
-	IOWorkLoop * wl;
-	uintptr_t  * sleepersP;
-
-	if (!inAction) {
-		return kIOReturnBadArgument;
-	}
-	if (!(wl = workLoop)) {
-		return kIOReturnNotReady;
-	}
-
-	// closeGate is recursive needn't worry if we already hold the lock.
-	wl->closeGate();
-	sleepersP = (uintptr_t *) &reserved;
-
-	// If the command gate is disabled and we aren't on the workloop thread
-	// itself then sleep until we get enabled.
-	IOReturn res;
-	if (!wl->onThread()) {
-		while (!enabled) {
-			IOReturn sleepResult = kIOReturnSuccess;
-			if (workLoop) {
-				*sleepersP |= kSleepersWaitEnabled;
-				sleepResult = wl->sleepGate(&enabled, THREAD_INTERRUPTIBLE);
-				*sleepersP &= ~kSleepersWaitEnabled;
-			}
-			bool wakeupTearDown = (!workLoop || (0 != (*sleepersP & kSleepersRemoved)));
-			if ((kIOReturnSuccess != sleepResult) || wakeupTearDown) {
-				wl->openGate();
-
-				if (wakeupTearDown) {
-					wl->wakeupGate(sleepersP, false); // No further resources used
-				}
-				return kIOReturnAborted;
-			}
-		}
-	}
-
-	bool trace = (gIOKitTrace & kIOTraceCommandGates) ? true : false;
-
-	if (trace) {
-		IOTimeStampStartConstant(IODBG_CMDQ(IOCMDQ_ACTION),
-		    VM_KERNEL_ADDRHIDE(inAction), VM_KERNEL_ADDRHIDE(owner));
-	}
-
-	IOStatisticsActionCall();
-
-	// Must be gated and on the work loop or enabled
-
-	*sleepersP += kSleepersActions;
-	res = (*inAction)(owner, arg0, arg1, arg2, arg3);
-	*sleepersP -= kSleepersActions;
-
-	if (trace) {
-		IOTimeStampEndConstant(IODBG_CMDQ(IOCMDQ_ACTION),
-		    VM_KERNEL_ADDRHIDE(inAction), VM_KERNEL_ADDRHIDE(owner));
-	}
-
-	if (kSleepersRemoved == ((kSleepersActionsMask | kSleepersRemoved) & *sleepersP)) {
-		// no actions outstanding
-		*sleepersP &= ~kSleepersRemoved;
-		super::setWorkLoop(NULL);
-	}
-
-	wl->openGate();
-
-	return res;
-}
-
-IOReturn
-IOCommandGate::attemptAction(Action inAction,
-    void *arg0, void *arg1,
-    void *arg2, void *arg3)
-{
-	IOReturn res;
-	IOWorkLoop * wl;
-
-	if (!inAction) {
-		return kIOReturnBadArgument;
-	}
-	if (!(wl = workLoop)) {
-		return kIOReturnNotReady;
-	}
-
-	// Try to close the gate if can't get return immediately.
-	if (!wl->tryCloseGate()) {
-		return kIOReturnCannotLock;
-	}
-
-	// If the command gate is disabled then sleep until we get a wakeup
-	if (!wl->onThread() && !enabled) {
-		res = kIOReturnNotPermitted;
-	} else {
-		bool trace = (gIOKitTrace & kIOTraceCommandGates) ? true : false;
-
-		if (trace) {
-			IOTimeStampStartConstant(IODBG_CMDQ(IOCMDQ_ACTION),
-			    VM_KERNEL_ADDRHIDE(inAction), VM_KERNEL_ADDRHIDE(owner));
-		}
-
-		IOStatisticsActionCall();
-
-		res = (*inAction)(owner, arg0, arg1, arg2, arg3);
-
-		if (trace) {
-			IOTimeStampEndConstant(IODBG_CMDQ(IOCMDQ_ACTION),
-			    VM_KERNEL_ADDRHIDE(inAction), VM_KERNEL_ADDRHIDE(owner));
-		}
-	}
-
-	wl->openGate();
-
-	return res;
-}
-
-IOReturn
-IOCommandGate::commandSleep(void *event, UInt32 interruptible)
-{
-	if (!workLoop->inGate()) {
-		/* The equivalent of 'msleep' while not holding the mutex is invalid */
-		panic("invalid commandSleep while not holding the gate");
-	}
-
-	return sleepGate(event, interruptible);
-}
-
-IOReturn
-IOCommandGate::commandSleep(void *event, AbsoluteTime deadline, UInt32 interruptible)
-{
-	if (!workLoop->inGate()) {
-		/* The equivalent of 'msleep' while not holding the mutex is invalid */
-		panic("invalid commandSleep while not holding the gate");
-	}
-
-	return sleepGate(event, deadline, interruptible);
-}
-
-void
-IOCommandGate::commandWakeup(void *event, bool oneThread)
-{
-	wakeupGate(event, oneThread);
-}