* Copyright (c) 1998-2000, 2009-2010 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
* 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,
* 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@
*/
#include <libkern/OSDebug.h>
#endif /* IOKITSTATS */
-bool IOCommandGate::init(OSObject *inOwner, Action inAction)
+bool
+IOCommandGate::init(OSObject *inOwner, Action inAction)
{
- bool res = super::init(inOwner, (IOEventSource::Action) inAction);
- if (res) {
- IOStatisticsInitializeCounter();
- }
+ bool res = super::init(inOwner, (IOEventSource::Action) inAction);
+ if (res) {
+ IOStatisticsInitializeCounter();
+ }
- return res;
+ return res;
}
IOCommandGate *
IOCommandGate::commandGate(OSObject *inOwner, Action inAction)
{
- IOCommandGate *me = new IOCommandGate;
+ IOCommandGate *me = new IOCommandGate;
- if (me && !me->init(inOwner, inAction)) {
- me->release();
- return 0;
- }
+ if (me && !me->init(inOwner, inAction)) {
+ me->release();
+ return 0;
+ }
- return me;
+ return me;
}
-/* virtual */ void IOCommandGate::disable()
+/* virtual */ void
+IOCommandGate::disable()
{
- if (workLoop && !workLoop->inGate())
- OSReportWithBacktrace("IOCommandGate::disable() called when not gated");
+ if (workLoop && !workLoop->inGate()) {
+ OSReportWithBacktrace("IOCommandGate::disable() called when not gated");
+ }
- super::disable();
+ super::disable();
}
-/* virtual */ void IOCommandGate::enable()
+/* virtual */ void
+IOCommandGate::enable()
{
- if (workLoop) {
- closeGate();
- super::enable();
- wakeupGate(&enabled, /* oneThread */ false); // Unblock sleeping threads
- openGate();
- }
+ if (workLoop) {
+ closeGate();
+ super::enable();
+ wakeupGate(&enabled, /* oneThread */ false); // Unblock sleeping threads
+ openGate();
+ }
}
-/* virtual */ void IOCommandGate::free()
+/* virtual */ void
+IOCommandGate::free()
{
- setWorkLoop(0);
- super::free();
+ if (workLoop) {
+ setWorkLoop(0);
+ }
+ super::free();
}
-/* virtual */ void IOCommandGate::setWorkLoop(IOWorkLoop *inWorkLoop)
+enum{
+ kSleepersRemoved = 0x00000001,
+ kSleepersWaitEnabled = 0x00000002,
+ kSleepersActions = 0x00000100,
+ kSleepersActionsMask = 0xffffff00,
+};
+
+/* virtual */ void
+IOCommandGate::setWorkLoop(IOWorkLoop *inWorkLoop)
{
- uintptr_t *sleepersP = (uintptr_t *) &reserved;
- if (!inWorkLoop && workLoop) { // tearing down
- closeGate();
- *sleepersP |= 1;
- while (*sleepersP >> 1) {
- thread_wakeup_with_result(&enabled, THREAD_INTERRUPTED);
- sleepGate(sleepersP, THREAD_UNINT);
+ IOWorkLoop * wl;
+ uintptr_t * sleepersP = (uintptr_t *) &reserved;
+ bool defer;
+
+ 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(0);
+ *sleepersP &= ~kSleepersRemoved;
+ }
+ wl->openGate();
+ return;
}
- *sleepersP = 0;
- openGate();
- }
- else
- super::setWorkLoop(inWorkLoop);
+ super::setWorkLoop(inWorkLoop);
}
-IOReturn IOCommandGate::runCommand(void *arg0, void *arg1,
- void *arg2, void *arg3)
+IOReturn
+IOCommandGate::runCommand(void *arg0, void *arg1,
+ void *arg2, void *arg3)
{
- return runAction((Action) action, arg0, arg1, arg2, arg3);
+ return runAction((Action) action, arg0, arg1, arg2, arg3);
}
-IOReturn IOCommandGate::attemptCommand(void *arg0, void *arg1,
- void *arg2, void *arg3)
+IOReturn
+IOCommandGate::attemptCommand(void *arg0, void *arg1,
+ void *arg2, void *arg3)
{
- return attemptAction((Action) action, arg0, arg1, arg2, arg3);
+ return attemptAction((Action) action, arg0, arg1, arg2, arg3);
}
-IOReturn IOCommandGate::runAction(Action inAction,
- void *arg0, void *arg1,
- void *arg2, void *arg3)
+
+static IOReturn
+IOCommandGateActionToBlock(OSObject *owner,
+ void *arg0, void *arg1,
+ void *arg2, void *arg3)
{
- if (!inAction)
- return kIOReturnBadArgument;
+ return ((IOEventSource::ActionBlock) arg0)();
+}
- // closeGate is recursive needn't worry if we already hold the lock.
- closeGate();
+IOReturn
+IOCommandGate::runActionBlock(ActionBlock action)
+{
+ return runAction(&IOCommandGateActionToBlock, action);
+}
- // If the command gate is disabled and we aren't on the workloop thread
- // itself then sleep until we get enabled.
- IOReturn res;
- if (!workLoop->onThread()) {
- while (!enabled) {
- uintptr_t *sleepersP = (uintptr_t *) &reserved;
+IOReturn
+IOCommandGate::runAction(Action inAction,
+ void *arg0, void *arg1,
+ void *arg2, void *arg3)
+{
+ IOWorkLoop * wl;
+ uintptr_t * sleepersP;
- *sleepersP += 2;
- IOReturn res = sleepGate(&enabled, THREAD_ABORTSAFE);
- *sleepersP -= 2;
+ if (!inAction) {
+ return kIOReturnBadArgument;
+ }
+ if (!(wl = workLoop)) {
+ return kIOReturnNotReady;
+ }
- bool wakeupTearDown = (*sleepersP & 1);
- if (res || wakeupTearDown) {
- openGate();
+ // 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;
+ }
+ }
+ }
- if (wakeupTearDown)
- commandWakeup(sleepersP); // No further resources used
+ bool trace = (gIOKitTrace & kIOTraceCommandGates) ? true : false;
- return kIOReturnAborted;
- }
+ if (trace) {
+ IOTimeStampStartConstant(IODBG_CMDQ(IOCMDQ_ACTION),
+ VM_KERNEL_ADDRHIDE(inAction), VM_KERNEL_ADDRHIDE(owner));
}
- }
- bool trace = ( gIOKitTrace & kIOTraceCommandGates ) ? true : false;
-
- if (trace)
- IOTimeStampStartConstant(IODBG_CMDQ(IOCMDQ_ACTION),
- VM_KERNEL_UNSLIDE(inAction), (uintptr_t) owner);
-
- IOStatisticsActionCall();
-
- // Must be gated and on the work loop or enabled
- res = (*inAction)(owner, arg0, arg1, arg2, arg3);
-
- if (trace)
+ 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_UNSLIDE(inAction), (uintptr_t) owner);
-
- openGate();
-
- return res;
+ VM_KERNEL_ADDRHIDE(inAction), VM_KERNEL_ADDRHIDE(owner));
+ }
+
+ if (kSleepersRemoved == ((kSleepersActionsMask | kSleepersRemoved) & *sleepersP)) {
+ // no actions outstanding
+ *sleepersP &= ~kSleepersRemoved;
+ super::setWorkLoop(0);
+ }
+
+ wl->openGate();
+
+ return res;
}
-IOReturn IOCommandGate::attemptAction(Action inAction,
- void *arg0, void *arg1,
- void *arg2, void *arg3)
+IOReturn
+IOCommandGate::attemptAction(Action inAction,
+ void *arg0, void *arg1,
+ void *arg2, void *arg3)
{
- IOReturn res;
-
- if (!inAction)
- return kIOReturnBadArgument;
-
- // Try to close the gate if can't get return immediately.
- if (!tryCloseGate())
- return kIOReturnCannotLock;
-
- // If the command gate is disabled then sleep until we get a wakeup
- if (!workLoop->onThread() && !enabled)
- res = kIOReturnNotPermitted;
- else {
-
- bool trace = ( gIOKitTrace & kIOTraceCommandGates ) ? true : false;
-
- if (trace)
- IOTimeStampStartConstant(IODBG_CMDQ(IOCMDQ_ACTION),
- VM_KERNEL_UNSLIDE(inAction), (uintptr_t) owner);
-
- IOStatisticsActionCall();
-
- res = (*inAction)(owner, arg0, arg1, arg2, arg3);
-
- if (trace)
- IOTimeStampEndConstant(IODBG_CMDQ(IOCMDQ_ACTION),
- VM_KERNEL_UNSLIDE(inAction), (uintptr_t) owner);
- }
-
- openGate();
-
- return res;
+ 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)
+IOReturn
+IOCommandGate::commandSleep(void *event, UInt32 interruptible)
{
- if (!workLoop->inGate())
- return kIOReturnNotPermitted;
+ 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);
+ return sleepGate(event, interruptible);
}
-IOReturn IOCommandGate::commandSleep(void *event, AbsoluteTime deadline, UInt32 interruptible)
+IOReturn
+IOCommandGate::commandSleep(void *event, AbsoluteTime deadline, UInt32 interruptible)
{
- if (!workLoop->inGate())
- return kIOReturnNotPermitted;
+ 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);
+ return sleepGate(event, deadline, interruptible);
}
-void IOCommandGate::commandWakeup(void *event, bool oneThread)
+void
+IOCommandGate::commandWakeup(void *event, bool oneThread)
{
- wakeupGate(event, oneThread);
+ wakeupGate(event, oneThread);
}
projects / apple / xnu.git / blobdiff