fixed SF# 1896482: tryReadLock intermittent error

This commit is contained in:
Guenter Obiltschnig
2008-09-17 19:13:50 +00:00
parent cf1d1fa952
commit c83f8e2434
3 changed files with 31 additions and 9 deletions

View File

@@ -1,7 +1,7 @@
//
// RWLock_WIN32.cpp
//
// $Id: //poco/svn/Foundation/src/RWLock_WIN32.cpp#2 $
// $Id: //poco/1.3/Foundation/src/RWLock_WIN32.cpp#3 $
//
// Library: Foundation
// Package: Threading
@@ -40,7 +40,7 @@
namespace Poco {
RWLockImpl::RWLockImpl(): _readers(0), _writers(0)
RWLockImpl::RWLockImpl(): _readers(0), _writersWaiting(0), _writers(0)
{
_mutex = CreateMutexW(NULL, FALSE, NULL);
if (_mutex == NULL)
@@ -69,7 +69,7 @@ inline void RWLockImpl::addWriter()
switch (WaitForSingleObject(_mutex, INFINITE))
{
case WAIT_OBJECT_0:
if (++_writers == 1) ResetEvent(_readEvent);
if (++_writersWaiting == 1) ResetEvent(_readEvent);
ReleaseMutex(_mutex);
break;
default:
@@ -83,7 +83,7 @@ inline void RWLockImpl::removeWriter()
switch (WaitForSingleObject(_mutex, INFINITE))
{
case WAIT_OBJECT_0:
if (--_writers == 0) SetEvent(_readEvent);
if (--_writersWaiting == 0 && _writers == 0) SetEvent(_readEvent);
ReleaseMutex(_mutex);
break;
default:
@@ -104,6 +104,7 @@ void RWLockImpl::readLockImpl()
++_readers;
ResetEvent(_writeEvent);
ReleaseMutex(_mutex);
poco_assert_dbg(_writers == 0);
break;
default:
throw SystemException("cannot lock reader/writer lock");
@@ -123,6 +124,7 @@ bool RWLockImpl::tryReadLockImpl()
++_readers;
ResetEvent(_writeEvent);
ReleaseMutex(_mutex);
poco_assert_dbg(_writers == 0);
return true;
case WAIT_TIMEOUT:
return false;
@@ -142,11 +144,13 @@ void RWLockImpl::writeLockImpl()
{
case WAIT_OBJECT_0:
case WAIT_OBJECT_0 + 1:
--_writers;
--_writersWaiting;
++_readers;
++_writers;
ResetEvent(_readEvent);
ResetEvent(_writeEvent);
ReleaseMutex(_mutex);
poco_assert_dbg(_writers == 1);
break;
default:
removeWriter();
@@ -165,11 +169,13 @@ bool RWLockImpl::tryWriteLockImpl()
{
case WAIT_OBJECT_0:
case WAIT_OBJECT_0 + 1:
--_writers;
--_writersWaiting;
++_readers;
++_writers;
ResetEvent(_readEvent);
ResetEvent(_writeEvent);
ReleaseMutex(_mutex);
poco_assert_dbg(_writers == 1);
return true;
case WAIT_TIMEOUT:
removeWriter();
@@ -186,7 +192,8 @@ void RWLockImpl::unlockImpl()
switch (WaitForSingleObject(_mutex, INFINITE))
{
case WAIT_OBJECT_0:
if (_writers == 0) SetEvent(_readEvent);
_writers = 0;
if (_writersWaiting == 0) SetEvent(_readEvent);
if (--_readers == 0) SetEvent(_writeEvent);
ReleaseMutex(_mutex);
break;