1 /* 2 * Copyright (c) 1998-2019 Apple Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28 /* Copyright (c) 1999 Apple Computer, Inc. All rights reserved. 29 * Copyright (c) 1994-1996 NeXT Software, Inc. All rights reserved. 30 */ 31 32 #ifndef _IOKIT_IOCONDITIONLOCK_H 33 #define _IOKIT_IOCONDITIONLOCK_H 34 35 #include <libkern/c++/OSPtr.h> 36 #include <libkern/c++/OSObject.h> 37 #include <IOKit/IOLib.h> 38 #include <IOKit/system.h> 39 40 #include <IOKit/IOLocks.h> 41 42 class IOConditionLock : public OSObject 43 { 44 OSDeclareDefaultStructors(IOConditionLock); 45 46 private: 47 IOLock * cond_interlock; // condition var Simple lock 48 volatile int condition; 49 50 IOLock * sleep_interlock; // sleep lock Simple lock 51 unsigned char interruptible; 52 volatile bool want_lock; 53 volatile bool waiting; 54 55 public: 56 static OSPtr<IOConditionLock> withCondition(int condition, bool inIntr = true); 57 virtual bool initWithCondition(int condition, bool inIntr = true); 58 virtual void free() APPLE_KEXT_OVERRIDE; 59 60 virtual bool tryLock(); // acquire lock, no waiting 61 virtual int lock(); // acquire lock (enter critical section) 62 virtual void unlock(); // release lock (leave critical section) 63 64 virtual bool getInterruptible() const; 65 virtual int getCondition() const; 66 virtual int setCondition(int condition); 67 68 virtual int lockWhen(int condition);// acquire lock when condition 69 virtual void unlockWith(int condition); // set condition & release lock 70 }; 71 72 #endif /* _IOKIT_IOCONDITIONLOCK_H */ 73