/*
* Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
*
- * @APPLE_LICENSE_HEADER_START@
- *
- * Copyright (c) 1999-2003 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. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
- *
+ * 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,
* 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_HEADER_END@
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/* Copyright (c) 1997 Apple Computer, Inc. All rights reserved.
- * Copyright (c) 1994-1996 NeXT Software, Inc. All rights reserved.
+ * Copyright (c) 1994-1996 NeXT Software, Inc. All rights reserved.
*
- * AppleIOPSSafeCondLock.m. Lock object with exported condition variable,
+ * AppleIOPSSafeCondLock.m. Lock object with exported condition variable,
* kernel version.
*
* HISTORY
* 1997-11-
* 01-Aug-91 Doug Mitchell at NeXT
- * Created.
+ * Created.
*/
#include <IOKit/IOConditionLock.h>
#define super OSObject
OSDefineMetaClassAndStructors(IOConditionLock, OSObject)
-bool IOConditionLock::initWithCondition(int inCondition, bool inIntr = true)
+bool
+IOConditionLock::initWithCondition(int inCondition, bool inIntr)
{
- if (!super::init())
- return false;
+ if (!super::init()) {
+ return false;
+ }
- cond_interlock = IOLockAlloc();
- sleep_interlock = IOLockAlloc();
+ cond_interlock = IOLockAlloc();
+ sleep_interlock = IOLockAlloc();
- condition = inCondition;
- want_lock = false;
- waiting = false;
- interruptible = (inIntr) ? THREAD_INTERRUPTIBLE : THREAD_UNINT;
+ condition = inCondition;
+ want_lock = false;
+ waiting = false;
+ interruptible = (inIntr) ? THREAD_INTERRUPTIBLE : THREAD_UNINT;
- return cond_interlock && sleep_interlock;
+ return cond_interlock && sleep_interlock;
}
-IOConditionLock *IOConditionLock::withCondition(int condition, bool intr = true)
+IOConditionLock *
+IOConditionLock::withCondition(int condition, bool intr)
{
- IOConditionLock *me = new IOConditionLock;
+ IOConditionLock *me = new IOConditionLock;
- if (me && !me->initWithCondition(condition, intr)) {
- me->free();
- return 0;
- }
+ if (me && !me->initWithCondition(condition, intr)) {
+ me->release();
+ return NULL;
+ }
- return me;
+ return me;
}
-void IOConditionLock::free()
+void
+IOConditionLock::free()
{
- if (cond_interlock)
- IOLockFree(cond_interlock);
- if (sleep_interlock)
- IOLockFree(sleep_interlock);
- super::free();
+ if (cond_interlock) {
+ IOLockFree(cond_interlock);
+ }
+ if (sleep_interlock) {
+ IOLockFree(sleep_interlock);
+ }
+ super::free();
}
-bool IOConditionLock::getInterruptible() const
+bool
+IOConditionLock::getInterruptible() const
{
- return interruptible;
+ return interruptible;
}
-int IOConditionLock:: getCondition() const
+int
+IOConditionLock:: getCondition() const
{
- return condition;
+ return condition;
}
-int IOConditionLock:: setCondition(int inCondition)
+int
+IOConditionLock:: setCondition(int inCondition)
{
- int old = condition;
+ int old = condition;
- condition = inCondition;
- thread_wakeup_one((void *) &condition);
+ condition = inCondition;
+ thread_wakeup_one((void *) &condition);
- return old;
+ return old;
}
-void IOConditionLock::unlock()
+void
+IOConditionLock::unlock()
{
- IOTakeLock(sleep_interlock);
+ IOTakeLock(sleep_interlock);
- thread_wakeup_one((void *) &condition);
+ thread_wakeup_one((void *) &condition);
- want_lock = false;
- if (waiting) {
- waiting = false;
- IOLockWakeup(sleep_interlock, this, /* one-thread */ false); // Wakeup everybody
- }
+ want_lock = false;
+ if (waiting) {
+ waiting = false;
+ IOLockWakeup(sleep_interlock, this, /* one-thread */ false); // Wakeup everybody
+ }
- IOUnlock(sleep_interlock);
+ IOUnlock(sleep_interlock);
}
-void IOConditionLock::unlockWith(int inCondition)
+void
+IOConditionLock::unlockWith(int inCondition)
{
- IOTakeLock(sleep_interlock);
- IOTakeLock(cond_interlock);
-
- condition = inCondition;
+ IOTakeLock(sleep_interlock);
+ IOTakeLock(cond_interlock);
+
+ condition = inCondition;
- IOUnlock(cond_interlock);
- IOUnlock(sleep_interlock);
+ IOUnlock(cond_interlock);
+ IOUnlock(sleep_interlock);
- unlock();
+ unlock();
}
-bool IOConditionLock::tryLock()
+bool
+IOConditionLock::tryLock()
{
- bool result;
+ bool result;
- IOTakeLock(sleep_interlock);
+ IOTakeLock(sleep_interlock);
- result = !want_lock;
- if (result)
- want_lock = true;
+ result = !want_lock;
+ if (result) {
+ want_lock = true;
+ }
- IOUnlock(sleep_interlock);
+ IOUnlock(sleep_interlock);
- return result;
+ return result;
}
-int IOConditionLock::lock()
+int
+IOConditionLock::lock()
{
- int thread_res = THREAD_AWAKENED;
-
- IOTakeLock(sleep_interlock);
-
- /* Try to acquire the want_lock bit. */
- while (want_lock && thread_res == THREAD_AWAKENED)
- {
- waiting = true;
- thread_res = IOLockSleep(sleep_interlock, (void *) this, interruptible);
- }
- if (thread_res == THREAD_AWAKENED)
- want_lock = true;
-
- IOUnlock(sleep_interlock);
-
- return thread_res;
+ int thread_res = THREAD_AWAKENED;
+
+ IOTakeLock(sleep_interlock);
+
+ /* Try to acquire the want_lock bit. */
+ while (want_lock && thread_res == THREAD_AWAKENED) {
+ waiting = true;
+ thread_res = IOLockSleep(sleep_interlock, (void *) this, interruptible);
+ }
+ if (thread_res == THREAD_AWAKENED) {
+ want_lock = true;
+ }
+
+ IOUnlock(sleep_interlock);
+
+ return thread_res;
}
-int IOConditionLock::lockWhen(int inCondition)
+int
+IOConditionLock::lockWhen(int inCondition)
{
- int thread_res;
-
- do
- {
- /* First get the actual lock */
- thread_res = lock();
- if (thread_res != THREAD_AWAKENED)
- break; // Failed to acquire lock
-
- if (inCondition == condition)
- break; // Hold lock and condition is expected value
-
- /*
- * Need to hold a IOTakeLock when we call thread_sleep().
- * Both _cond_interlock and want_lock must be held to
- * change _condition.
- */
- IOTakeLock(cond_interlock);
- unlock(); // Release lock and sleep
-
- /*
- * this is the critical section on a multi in which
- * another thread could hold _sleep_interlock, but they
- * can't change _condition. Holding _cond_interlock here
- * (until after assert_wait() is called from
- * thread_sleep()) ensures that we'll be notified
- * of changes in _condition.
- */
- assert_wait((void *) &condition, interruptible); /* assert event */
- IOUnlock(cond_interlock); /* release the lock */
- thread_res = thread_block(THREAD_CONTINUE_NULL); /* block ourselves */
- } while (thread_res == THREAD_AWAKENED);
-
- return thread_res;
+ int thread_res;
+
+ do{
+ /* First get the actual lock */
+ thread_res = lock();
+ if (thread_res != THREAD_AWAKENED) {
+ break; // Failed to acquire lock
+ }
+ if (inCondition == condition) {
+ break; // Hold lock and condition is expected value
+ }
+ /*
+ * Need to hold a IOTakeLock when we call thread_sleep().
+ * Both _cond_interlock and want_lock must be held to
+ * change _condition.
+ */
+ IOTakeLock(cond_interlock);
+ unlock(); // Release lock and sleep
+
+ /*
+ * this is the critical section on a multi in which
+ * another thread could hold _sleep_interlock, but they
+ * can't change _condition. Holding _cond_interlock here
+ * (until after assert_wait() is called from
+ * thread_sleep()) ensures that we'll be notified
+ * of changes in _condition.
+ */
+ assert_wait((void *) &condition, interruptible); /* assert event */
+ IOUnlock(cond_interlock); /* release the lock */
+ thread_res = thread_block(THREAD_CONTINUE_NULL); /* block ourselves */
+ } while (thread_res == THREAD_AWAKENED);
+
+ return thread_res;
}
projects / apple / xnu.git / blobdiff