1*b5088357SAndrew Rist /************************************************************** 2cdf0e10cSrcweir * 3*b5088357SAndrew Rist * Licensed to the Apache Software Foundation (ASF) under one 4*b5088357SAndrew Rist * or more contributor license agreements. See the NOTICE file 5*b5088357SAndrew Rist * distributed with this work for additional information 6*b5088357SAndrew Rist * regarding copyright ownership. The ASF licenses this file 7*b5088357SAndrew Rist * to you under the Apache License, Version 2.0 (the 8*b5088357SAndrew Rist * "License"); you may not use this file except in compliance 9*b5088357SAndrew Rist * with the License. You may obtain a copy of the License at 10*b5088357SAndrew Rist * 11*b5088357SAndrew Rist * http://www.apache.org/licenses/LICENSE-2.0 12*b5088357SAndrew Rist * 13*b5088357SAndrew Rist * Unless required by applicable law or agreed to in writing, 14*b5088357SAndrew Rist * software distributed under the License is distributed on an 15*b5088357SAndrew Rist * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16*b5088357SAndrew Rist * KIND, either express or implied. See the License for the 17*b5088357SAndrew Rist * specific language governing permissions and limitations 18*b5088357SAndrew Rist * under the License. 19*b5088357SAndrew Rist * 20*b5088357SAndrew Rist *************************************************************/ 21*b5088357SAndrew Rist 22*b5088357SAndrew Rist 23cdf0e10cSrcweir 24cdf0e10cSrcweir // MARKER(update_precomp.py): autogen include statement, do not remove 25cdf0e10cSrcweir #include "precompiled_unotools.hxx" 26cdf0e10cSrcweir #include "unotools/readwritemutexguard.hxx" 27cdf0e10cSrcweir #include <tools/debug.hxx> 28cdf0e10cSrcweir 29cdf0e10cSrcweir 30cdf0e10cSrcweir namespace utl { 31cdf0e10cSrcweir ReadWriteGuard(ReadWriteMutex & rMutexP,sal_Int32 nRequestMode)32cdf0e10cSrcweirReadWriteGuard::ReadWriteGuard( ReadWriteMutex& rMutexP, 33cdf0e10cSrcweir sal_Int32 nRequestMode ) 34cdf0e10cSrcweir : rMutex( rMutexP ) 35cdf0e10cSrcweir { 36cdf0e10cSrcweir // don't do anything until a pending write completed (or another 37cdf0e10cSrcweir // ReadWriteGuard leaves the ctor phase) 38cdf0e10cSrcweir ::osl::MutexGuard aGuard( rMutex.pWriteMutex ); 39cdf0e10cSrcweir nMode = nRequestMode; 40cdf0e10cSrcweir if ( nMode & ReadWriteGuardMode::nWrite ) 41cdf0e10cSrcweir { 42cdf0e10cSrcweir rMutex.pWriteMutex->acquire(); 43cdf0e10cSrcweir // wait for any read to complete 44cdf0e10cSrcweir // TODO: set up a waiting thread instead of a loop 45cdf0e10cSrcweir sal_Bool bWait = sal_True; 46cdf0e10cSrcweir do 47cdf0e10cSrcweir { 48cdf0e10cSrcweir rMutex.pMutex->acquire(); 49cdf0e10cSrcweir bWait = (rMutex.nReadCount != 0); 50cdf0e10cSrcweir if ( nMode & ReadWriteGuardMode::nCriticalChange ) 51cdf0e10cSrcweir bWait |= (rMutex.nBlockCriticalCount != 0); 52cdf0e10cSrcweir rMutex.pMutex->release(); 53cdf0e10cSrcweir } while ( bWait ); 54cdf0e10cSrcweir } 55cdf0e10cSrcweir else if ( nMode & ReadWriteGuardMode::nBlockCritical ) 56cdf0e10cSrcweir { 57cdf0e10cSrcweir rMutex.pMutex->acquire(); 58cdf0e10cSrcweir ++rMutex.nBlockCriticalCount; 59cdf0e10cSrcweir rMutex.pMutex->release(); 60cdf0e10cSrcweir } 61cdf0e10cSrcweir else 62cdf0e10cSrcweir { 63cdf0e10cSrcweir rMutex.pMutex->acquire(); 64cdf0e10cSrcweir ++rMutex.nReadCount; 65cdf0e10cSrcweir rMutex.pMutex->release(); 66cdf0e10cSrcweir } 67cdf0e10cSrcweir } 68cdf0e10cSrcweir 69cdf0e10cSrcweir ~ReadWriteGuard()70cdf0e10cSrcweirReadWriteGuard::~ReadWriteGuard() 71cdf0e10cSrcweir { 72cdf0e10cSrcweir if ( nMode & ReadWriteGuardMode::nWrite ) 73cdf0e10cSrcweir rMutex.pWriteMutex->release(); 74cdf0e10cSrcweir else if ( nMode & ReadWriteGuardMode::nBlockCritical ) 75cdf0e10cSrcweir { 76cdf0e10cSrcweir rMutex.pMutex->acquire(); 77cdf0e10cSrcweir --rMutex.nBlockCriticalCount; 78cdf0e10cSrcweir rMutex.pMutex->release(); 79cdf0e10cSrcweir } 80cdf0e10cSrcweir else 81cdf0e10cSrcweir { 82cdf0e10cSrcweir rMutex.pMutex->acquire(); 83cdf0e10cSrcweir --rMutex.nReadCount; 84cdf0e10cSrcweir rMutex.pMutex->release(); 85cdf0e10cSrcweir } 86cdf0e10cSrcweir } 87cdf0e10cSrcweir 88cdf0e10cSrcweir changeReadToWrite()89cdf0e10cSrcweirvoid ReadWriteGuard::changeReadToWrite() 90cdf0e10cSrcweir { 91cdf0e10cSrcweir sal_Bool bOk = !(nMode & (ReadWriteGuardMode::nWrite | ReadWriteGuardMode::nBlockCritical)); 92cdf0e10cSrcweir DBG_ASSERT( bOk, "ReadWriteGuard::changeReadToWrite: can't" ); 93cdf0e10cSrcweir if ( bOk ) 94cdf0e10cSrcweir { 95cdf0e10cSrcweir // MUST release read before acquiring write mutex or dead lock would 96cdf0e10cSrcweir // occur if there was a write in another thread waiting for this read 97cdf0e10cSrcweir // to complete. 98cdf0e10cSrcweir rMutex.pMutex->acquire(); 99cdf0e10cSrcweir --rMutex.nReadCount; 100cdf0e10cSrcweir rMutex.pMutex->release(); 101cdf0e10cSrcweir 102cdf0e10cSrcweir rMutex.pWriteMutex->acquire(); 103cdf0e10cSrcweir nMode |= ReadWriteGuardMode::nWrite; 104cdf0e10cSrcweir // wait for any other read to complete 105cdf0e10cSrcweir // TODO: set up a waiting thread instead of a loop 106cdf0e10cSrcweir sal_Bool bWait = sal_True; 107cdf0e10cSrcweir do 108cdf0e10cSrcweir { 109cdf0e10cSrcweir rMutex.pMutex->acquire(); 110cdf0e10cSrcweir bWait = (rMutex.nReadCount != 0); 111cdf0e10cSrcweir rMutex.pMutex->release(); 112cdf0e10cSrcweir } while ( bWait ); 113cdf0e10cSrcweir } 114cdf0e10cSrcweir } 115cdf0e10cSrcweir 116cdf0e10cSrcweir } // namespace utl 117