persistentstorage/sqlite3api/OsLayer/os_symbian_mt.cpp
branchRCL_3
changeset 11 667e88a979d7
parent 10 fa9941cf3867
child 31 ba1c4f4a893f
equal deleted inserted replaced
10:fa9941cf3867 11:667e88a979d7
     1 // Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies).
     1 // Copyright (c) 2005-2010 Nokia Corporation and/or its subsidiary(-ies).
     2 // All rights reserved.
     2 // All rights reserved.
     3 // This component and the accompanying materials are made available
     3 // This component and the accompanying materials are made available
     4 // under the terms of "Eclipse Public License v1.0"
     4 // under the terms of "Eclipse Public License v1.0"
     5 // which accompanies this distribution, and is available
     5 // which accompanies this distribution, and is available
     6 // at the URL "http://www.eclipse.org/legal/epl-v10.html".
     6 // at the URL "http://www.eclipse.org/legal/epl-v10.html".
   152 /**
   152 /**
   153 Gives the calling thread an exclusive access to the SQLite resources (global variables, file handles, buffers, cache, etc.).
   153 Gives the calling thread an exclusive access to the SQLite resources (global variables, file handles, buffers, cache, etc.).
   154 The calling thread becomes a mutex owner.
   154 The calling thread becomes a mutex owner.
   155 If the mutex is already locked by another thread, the calling thread will block until the other thread releases the mutex.
   155 If the mutex is already locked by another thread, the calling thread will block until the other thread releases the mutex.
   156 The method can be called by the mutex owning thread more than once, even if the mutex is already entered.
   156 The method can be called by the mutex owning thread more than once, even if the mutex is already entered.
       
   157 
       
   158 @panic SqliteMt 23 Negative mutex lock counter (in debug builds only)
   157 */
   159 */
   158 void sqlite3_mutex::Enter()
   160 void sqlite3_mutex::Enter()
   159 	{
   161 	{
       
   162     __ASSERT_DEBUG(iRefCount >= 0, User::Panic(KPanicCategory, EPanicMutexLockCounter));
   160 	iMutex.Wait();
   163 	iMutex.Wait();
   161 	RThread currThread;
   164 	RThread currThread;
   162 	iOwnerThreadId = currThread.Id();
   165 	iOwnerThreadId = currThread.Id();
   163 	++iRefCount;
   166 	++iRefCount;
   164 	}
   167 	}
   189 @return True if the mutex is locked, false otherwise
   192 @return True if the mutex is locked, false otherwise
   190 */
   193 */
   191 TBool sqlite3_mutex::IsHeld() const
   194 TBool sqlite3_mutex::IsHeld() const
   192 	{
   195 	{
   193 	RThread currThread;
   196 	RThread currThread;
   194 	return iRefCount != 0 && iOwnerThreadId == currThread.Id();
   197 	return iRefCount > 0 && iOwnerThreadId == currThread.Id();
   195 	}
   198 	}
   196 
   199 
   197 /**
   200 /**
   198 Creates the mutex.
   201 Creates the mutex.
   199 
   202 
   272 		case SQLITE_MUTEX_FAST:
   275 		case SQLITE_MUTEX_FAST:
   273 		case SQLITE_MUTEX_RECURSIVE:
   276 		case SQLITE_MUTEX_RECURSIVE:
   274 			mutex = CRecursiveMutex::New();
   277 			mutex = CRecursiveMutex::New();
   275 			break;
   278 			break;
   276 		default:
   279 		default:
   277 			mutex = ::StaticMutex(aType - 2);
   280 			mutex = ::StaticMutex(aType - 2);//"aType - 2" because the first SQLITE_MUTEX_STATIC_<type> mutex definition 
       
   281 			//value is 2 (SQLITE_MUTEX_FAST is 0, SQLITE_MUTEX_RECURSIVE is 1). 
   278 			break;	
   282 			break;	
   279 		}
   283 		}
   280 	return mutex;
   284 	return mutex;
   281 	}
   285 	}
   282 	
   286 	
   415 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
   419 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
   416 //////////////////////////  TheMutexMethods  //////////////////////////////////////////////////////////////////////////////////
   420 //////////////////////////  TheMutexMethods  //////////////////////////////////////////////////////////////////////////////////
   417 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
   421 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
   418 
   422 
   419 /**
   423 /**
       
   424 sqlite3_mutex_methods is a structure declared in sqlite3.h header file. 
       
   425 sqlite3_mutex_methods defines the mutex interface used by SQLite and implemented by the OS porting layer.
   420 */
   426 */
   421 static sqlite3_mutex_methods TheMutexMethods =
   427 static sqlite3_mutex_methods TheMutexMethods =
   422 	{
   428 	{
   423 	&TMutexApi::Init,
   429 	&TMutexApi::Init,
   424 	&TMutexApi::End,
   430 	&TMutexApi::End,
  1025 SQLite OS porting layer API.
  1031 SQLite OS porting layer API.
  1026 
  1032 
  1027 Checks if the file lock type is SQLITE_LOCK_RESERVED or bigger.
  1033 Checks if the file lock type is SQLITE_LOCK_RESERVED or bigger.
  1028 
  1034 
  1029 @param aDbFile A pointer to a TDbFile instance, that contains the file handle.
  1035 @param aDbFile A pointer to a TDbFile instance, that contains the file handle.
  1030 @param aResOut Output parameter. It should be set to 1 if the stored lock type is bigger or equal 
  1036 @param aResOut Output parameter. It will be set to be non-zero if the stored lock type is bigger or equal 
  1031 							     than SQLITE_LOCK_RESERVED.
  1037 							     than SQLITE_LOCK_RESERVED.
  1032 
  1038 
  1033 @return SQLITE_IOERR_CHECKRESERVEDLOCK, The operation has failed,
  1039 @return SQLITE_IOERR_CHECKRESERVEDLOCK, The operation has failed,
  1034 	    SQLITE_OK 					    The operation has completed successfully.
  1040 	    SQLITE_OK 					    The operation has completed successfully.
  1035 
  1041