csutil/threading/win32_mutex.h Source File (Crystal Space 2.0 Public API Reference)

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csutil/threading/win32_mutex.h

    00001 /*
    00002   Copyright (C) 2006 by Marten Svanfeldt
    00003
    00004   This library is free software; you can redistribute it and/or
    00005   modify it under the terms of the GNU Lesser General Public
    00006   License as published by the Free Software Foundation; either
    00007   version 2 of the License, or (at your option) any later version.
    00008
    00009   This library is distributed in the hope that it will be useful,
    00010   but WITHOUT ANY WARRANTY; without even the implied warranty of
    00011   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    00012   Library General Public License for more details.
    00013
    00014   You should have received a copy of the GNU Library General Public
    00015   License along with this library; if not, write to the Free
    00016   Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
    00017 */
    00018
    00019 #ifndef __CS_CSUTIL_THREADING_WIN32_MUTEX_H__
    00020 #define __CS_CSUTIL_THREADING_WIN32_MUTEX_H__
    00021
    00022 #include "csutil/threading/atomicops.h"
    00023 #include "csutil/threading/win32_apifuncs.h"
    00024
    00025 #if !defined(CS_PLATFORM_WIN32)
    00026 #error "This file is only for Windows and requires you to include csysdefs.h before"
    00027 #else
    00028
    00029 #ifdef CS_THREAD_CHECKER
    00030 #include <libittnotify.h>
    00031 #endif
    00032
    00033 namespace CS
    00034 {
    00035 namespace Threading
    00036 {
    00037 namespace Implementation
    00038 {
    00039
    00043   class MutexBase
    00044   {
    00045   public:
    00046     void Initialize ()
    00047     {
    00048       activeFlag = 0;
    00049       semaphore = 0;
    00050     }
    00051
    00052     void Destroy ()
    00053     {
    00054       void* oldSemaphore = AtomicOperations::Set (&semaphore, (void*)0);
    00055       if (oldSemaphore)
    00056       {
    00057         Implementation::CloseHandle (semaphore);
    00058       }
    00059     }
    00060
    00061
    00062     bool Lock ()
    00063     {
    00064 #ifdef CS_THREAD_CHECKER
    00065       __itt_notify_sync_prepare((void *)this);
    00066 #endif
    00067       if (AtomicOperations::Increment (&activeFlag) != 1)
    00068       {
    00069         Implementation::WaitForSingleObject (GetSemaphore (), INFINITE);
    00070       }
    00071 #ifdef CS_THREAD_CHECKER
    00072       __itt_notify_sync_acquired((void *)this);
    00073 #endif
    00074       return IsLocked ();
    00075     }
    00076
    00077     bool TryLock ()
    00078     {
    00079 #ifdef CS_THREAD_CHECKER
    00080       __itt_notify_sync_prepare((void *)this);
    00081       bool locked = !AtomicOperations::CompareAndSet (&activeFlag, 1, 0);
    00082       if(locked)
    00083         __itt_notify_sync_acquired((void *)this);
    00084       else
    00085         __itt_notify_sync_cancel((void *)this);
    00086       return locked;
    00087 #else
    00088       return !AtomicOperations::CompareAndSet (&activeFlag, 1, 0);
    00089 #endif
    00090     }
    00091
    00092     void Unlock ()
    00093     {
    00094 #ifdef CS_THREAD_CHECKER
    00095       __itt_notify_sync_releasing((void *)this);
    00096 #endif
    00097       if (AtomicOperations::Decrement (&activeFlag) > 0)
    00098       {
    00099         Implementation::ReleaseSemaphore (GetSemaphore (), 1, 0);
    00100       }
    00101     }
    00102
    00103   protected:
    00104     friend class RecursiveMutexBase;
    00105     bool IsLocked ()
    00106     {
    00107       return AtomicOperations::Read (&activeFlag) > 0;
    00108     }
    00109
    00110     void* GetSemaphore ()
    00111     {
    00112       void* currentSem = AtomicOperations::Read (&semaphore);
    00113       if (!currentSem)
    00114       {
    00115         //Create a new semaphore and try to set it
    00116         void* const newSem = Implementation::CreateSemaphoreA (0,0,1,0);
    00117         void* const oldSem = AtomicOperations::CompareAndSet (&semaphore,
    00118           newSem, 0);
    00119
    00120         //We already have one, use it
    00121         if (oldSem != 0)
    00122         {
    00123           Implementation::CloseHandle (newSem);
    00124           return oldSem;
    00125         }
    00126         else
    00127         {
    00128           //We didn't have any before, so use our new semaphore
    00129           return newSem;
    00130         }
    00131       }
    00132       return currentSem;
    00133     }
    00134
    00135     int32 activeFlag; //Lock flag for mutex
    00136     void* semaphore; //Semaphore for being able to wait for
    00137   };
    00138
    00139
    00143   class RecursiveMutexBase
    00144   {
    00145   public:
    00146     void Initialize ()
    00147     {
    00148       recursionCount = 0;
    00149       lockingThreadID = 0;
    00150       mutex.Initialize ();
    00151     }
    00152
    00153     void Destroy ()
    00154     {
    00155       mutex.Destroy ();
    00156     }
    00157
    00158     bool IsLocked ()
    00159     {
    00160       return mutex.IsLocked ();
    00161     }
    00162
    00163     bool Lock ()
    00164     {
    00165       int32 currentThreadID = (int32)Implementation::GetCurrentThreadId ();
    00166       if (!TryRecursiveLock (currentThreadID))
    00167       {
    00168         mutex.Lock ();
    00169         AtomicOperations::Set (&lockingThreadID, currentThreadID);
    00170         recursionCount = 1;
    00171       }
    00172       return IsLocked ();
    00173     }
    00174
    00175     bool TryLock ()
    00176     {
    00177       int32 currentThreadID = (int32)Implementation::GetCurrentThreadId ();
    00178       return TryRecursiveLock (currentThreadID) ||
    00179              TryNormalLock (currentThreadID);
    00180     }
    00181
    00182     void Unlock ()
    00183     {
    00184       if(!--recursionCount)
    00185       {
    00186         AtomicOperations::Set (&lockingThreadID, 0);
    00187         mutex.Unlock ();
    00188       }
    00189     }
    00190
    00191   private:
    00192     bool TryRecursiveLock (int32 currentThreadID)
    00193     {
    00194       if (AtomicOperations::Read (&lockingThreadID) == currentThreadID)
    00195       {
    00196         ++recursionCount;
    00197         return true;
    00198       }
    00199       return false;
    00200     }
    00201
    00202     bool TryNormalLock (int32 currentThreadID)
    00203     {
    00204       if (mutex.TryLock ())
    00205       {
    00206         AtomicOperations::Set (&lockingThreadID, currentThreadID);
    00207         recursionCount = 1;
    00208         return true;
    00209       }
    00210       return false;
    00211     }
    00212
    00213     MutexBase mutex; //Non-recursive base-mutex
    00214     int32 recursionCount;
    00215     int32 lockingThreadID;
    00216   };
    00217
    00218 } // namespace Implementation
    00219 } // namespace Threading
    00220 } // namespace CS
    00221
    00222 #endif // !defined(CS_PLATFORM_WIN32)
    00223
    00224 #endif // __CS_CSUTIL_THREADING_WIN32_MUTEX_H__