iokit/IOKit/IOConditionLock.h

   1 /*
   2  * Copyright (c) 1998-2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_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. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /* Copyright (c) 1999 Apple Computer, Inc.  All rights reserved.
  24  * Copyright (c) 1994-1996 NeXT Software, Inc.  All rights reserved.
  25  */
  26
  27 #ifndef _IOKIT_IOCONDITIONLOCK_H
  28 #define _IOKIT_IOCONDITIONLOCK_H
  29
  30 #include <libkern/c++/OSObject.h>
  31 #include <IOKit/IOLib.h>
  32 #include <IOKit/system.h>
  33
  34 #include <IOKit/IOLocks.h>
  35
  36 class IOConditionLock : public OSObject
  37 {
  38     OSDeclareDefaultStructors(IOConditionLock)
  39
  40 private:
  41     IOLock *            cond_interlock;         // condition var Simple lock
  42     volatile int        condition;
  43
  44     IOLock *            sleep_interlock;        // sleep lock Simple lock
  45     unsigned char       interruptible;
  46     volatile bool       want_lock;
  47     volatile bool       waiting;
  48
  49 public:
  50     static IOConditionLock *withCondition(int condition, bool inIntr = true);
  51     virtual bool initWithCondition(int condition, bool inIntr = true);
  52     virtual void free();
  53
  54     virtual bool tryLock();     // acquire lock, no waiting
  55     virtual int  lock();        // acquire lock (enter critical section)
  56     virtual void unlock();      // release lock (leave critical section)
  57
  58     virtual bool getInterruptible() const;
  59     virtual int  getCondition() const;
  60     virtual int  setCondition(int condition);
  61
  62     virtual int  lockWhen(int condition); // acquire lock when condition
  63     virtual void unlockWith(int condition); // set condition & release lock
  64 };
  65
  66 #endif /* _IOKIT_IOCONDITIONLOCK_H */