headers/os/support/Autolock.h

   1 /*
   2  * Copyright 2001-2009, Haiku, Inc. All Rights Reserved.
   3  * Distributed under the terms of the MIT License.
   4  */
   5 #ifndef _AUTOLOCK_H
   6 #define _AUTOLOCK_H
   7
   8
   9 #include <Locker.h>
  10 #include <Looper.h>
  11
  12
  13 class BAutolock {
  14 public:
  15         inline                                          BAutolock(BLooper* looper);
  16         inline                                          BAutolock(BLocker* locker);
  17         inline                                          BAutolock(BLocker& locker);
  18         inline                                          ~BAutolock();
  19
  20         inline  bool                            IsLocked();
  21
  22         inline  bool                            Lock();
  23         inline  void                            Unlock();
  24
  25 private:
  26                         BLocker*                        fLocker;
  27                         BLooper*                        fLooper;
  28                         bool                            fIsLocked;
  29 };
  30
  31
  32 inline
  33 BAutolock::BAutolock(BLooper *looper)
  34         :
  35         fLocker(NULL),
  36         fLooper(looper),
  37         fIsLocked(looper->Lock())
  38 {
  39 }
  40
  41
  42 inline
  43 BAutolock::BAutolock(BLocker *locker)
  44         :
  45         fLocker(locker),
  46         fLooper(NULL),
  47         fIsLocked(locker->Lock())
  48 {
  49 }
  50
  51
  52 inline
  53 BAutolock::BAutolock(BLocker &locker)
  54         :
  55         fLocker(&locker),
  56         fLooper(NULL),
  57         fIsLocked(locker.Lock())
  58 {
  59 }
  60
  61
  62 inline
  63 BAutolock::~BAutolock()
  64 {
  65         Unlock();
  66 }
  67
  68
  69 inline bool
  70 BAutolock::IsLocked()
  71 {
  72         return fIsLocked;
  73 }
  74
  75
  76 inline bool
  77 BAutolock::Lock()
  78 {
  79         if (fIsLocked)
  80                 return true;
  81
  82         if (fLooper != NULL)
  83                 fIsLocked = fLooper->Lock();
  84         else
  85                 fIsLocked = fLocker->Lock();
  86
  87         return fIsLocked;
  88 }
  89
  90
  91 inline void
  92 BAutolock::Unlock()
  93 {
  94         if (!fIsLocked)
  95                 return;
  96
  97         fIsLocked = false;
  98         if (fLooper != NULL)
  99                 fLooper->Unlock();
 100         else
 101                 fLocker->Unlock();
 102 }
 103
 104
 105 #endif  // _AUTOLOCK_H