You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
350 lines
11 KiB
350 lines
11 KiB
/****************************************************************************
|
|
**
|
|
** ...
|
|
**
|
|
** Copyright (C) 2005-2008 Trolltech ASA. All rights reserved.
|
|
**
|
|
** This file is part of the tools module of the Qt GUI Toolkit.
|
|
**
|
|
** This file may be used under the terms of the GNU General
|
|
** Public License versions 2.0 or 3.0 as published by the Free
|
|
** Software Foundation and appearing in the files LICENSE.GPL2
|
|
** and LICENSE.GPL3 included in the packaging of this file.
|
|
** Alternatively you may (at your option) use any later version
|
|
** of the GNU General Public License if such license has been
|
|
** publicly approved by Trolltech ASA (or its successors, if any)
|
|
** and the KDE Free Qt Foundation.
|
|
**
|
|
** Please review the following information to ensure GNU General
|
|
** Public Licensing requirements will be met:
|
|
** http://trolltech.com/products/qt/licenses/licensing/opensource/.
|
|
** If you are unsure which license is appropriate for your use, please
|
|
** review the following information:
|
|
** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
|
|
** or contact the sales department at sales@trolltech.com.
|
|
**
|
|
** This file may be used under the terms of the Q Public License as
|
|
** defined by Trolltech ASA and appearing in the file LICENSE.QPL
|
|
** included in the packaging of this file. Licensees holding valid Qt
|
|
** Commercial licenses may use this file in accordance with the Qt
|
|
** Commercial License Agreement provided with the Software.
|
|
**
|
|
** This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
|
|
** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
|
|
** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted
|
|
** herein.
|
|
**
|
|
**********************************************************************/
|
|
|
|
#ifdef QT_THREAD_SUPPORT
|
|
|
|
#include "qplatformdefs.h"
|
|
|
|
#include "qthreadstorage.h"
|
|
#include <private/qthreadinstance_p.h>
|
|
|
|
#include <string.h>
|
|
|
|
// #define QTHREADSTORAGE_DEBUG
|
|
|
|
|
|
// keep this in sync with the implementation in qthreadstorage.cpp
|
|
static const int MAX_THREAD_STORAGE = 257; // 256 maximum + 1 used in QRegExp
|
|
|
|
static pthread_mutex_t thread_storage_mutex = PTHREAD_MUTEX_INITIALIZER;
|
|
|
|
static bool thread_storage_init = FALSE;
|
|
static struct {
|
|
bool used;
|
|
void (*func)( void * );
|
|
} thread_storage_usage[MAX_THREAD_STORAGE];
|
|
|
|
|
|
QThreadStorageData::QThreadStorageData( void (*func)( void * ) )
|
|
: id( 0 )
|
|
{
|
|
pthread_mutex_lock( &thread_storage_mutex );
|
|
|
|
// make sure things are initialized
|
|
if ( ! thread_storage_init )
|
|
memset( thread_storage_usage, 0, sizeof( thread_storage_usage ) );
|
|
thread_storage_init = TRUE;
|
|
|
|
for ( ; id < MAX_THREAD_STORAGE; ++id ) {
|
|
if ( !thread_storage_usage[id].used )
|
|
break;
|
|
}
|
|
|
|
Q_ASSERT( id >= 0 && id < MAX_THREAD_STORAGE );
|
|
thread_storage_usage[id].used = TRUE;
|
|
thread_storage_usage[id].func = func;
|
|
|
|
#ifdef QTHREADSTORAGE_DEBUG
|
|
qDebug( "QThreadStorageData: allocated id %d", id );
|
|
#endif // QTHREADSTORAGE_DEBUG
|
|
|
|
pthread_mutex_unlock( &thread_storage_mutex );
|
|
}
|
|
|
|
QThreadStorageData::~QThreadStorageData()
|
|
{
|
|
pthread_mutex_lock( &thread_storage_mutex );
|
|
thread_storage_usage[id].used = FALSE;
|
|
thread_storage_usage[id].func = 0;
|
|
|
|
#ifdef QTHREADSTORAGE_DEBUG
|
|
qDebug( "QThreadStorageData: released id %d", id );
|
|
#endif // QTHREADSTORAGE_DEBUG
|
|
|
|
pthread_mutex_unlock( &thread_storage_mutex );
|
|
}
|
|
|
|
void **QThreadStorageData::get() const
|
|
{
|
|
QThreadInstance *d = QThreadInstance::current();
|
|
if (!d) {
|
|
qWarning("QThreadStorage can only be used with threads started with QThread");
|
|
return 0;
|
|
}
|
|
QMutexLocker locker( d->mutex() );
|
|
return d->thread_storage && d->thread_storage[id] ? &d->thread_storage[id] : 0;
|
|
}
|
|
|
|
void **QThreadStorageData::set( void *p )
|
|
{
|
|
QThreadInstance *d = QThreadInstance::current();
|
|
if (!d) {
|
|
qWarning("QThreadStorage can only be used with threads started with QThread");
|
|
return 0;
|
|
}
|
|
QMutexLocker locker( d->mutex() );
|
|
if ( !d->thread_storage ) {
|
|
#ifdef QTHREADSTORAGE_DEBUG
|
|
qDebug( "QThreadStorageData: allocating storage for thread %lx",
|
|
(unsigned long) pthread_self() );
|
|
#endif // QTHREADSTORAGE_DEBUG
|
|
|
|
d->thread_storage = new void*[MAX_THREAD_STORAGE];
|
|
memset( d->thread_storage, 0, sizeof( void* ) * MAX_THREAD_STORAGE );
|
|
}
|
|
|
|
// delete any previous data
|
|
if ( d->thread_storage[id] )
|
|
thread_storage_usage[id].func( d->thread_storage[id] );
|
|
|
|
// store new data
|
|
d->thread_storage[id] = p;
|
|
return &d->thread_storage[id];
|
|
}
|
|
|
|
void QThreadStorageData::finish( void **thread_storage )
|
|
{
|
|
if ( ! thread_storage ) return; // nothing to do
|
|
|
|
#ifdef QTHREADSTORAGE_DEBUG
|
|
qDebug( "QThreadStorageData: destroying storage for thread %lx",
|
|
(unsigned long) pthread_self() );
|
|
#endif // QTHREADSTORAGE_DEBUG
|
|
|
|
for ( int i = 0; i < MAX_THREAD_STORAGE; ++i ) {
|
|
if ( ! thread_storage[i] ) continue;
|
|
if ( ! thread_storage_usage[i].used ) {
|
|
#ifdef QT_CHECK_STATE
|
|
qWarning( "QThreadStorage: thread %lx exited after QThreadStorage destroyed",
|
|
(unsigned long) pthread_self() );
|
|
#endif // QT_CHECK_STATE
|
|
continue;
|
|
}
|
|
|
|
thread_storage_usage[i].func( thread_storage[i] );
|
|
}
|
|
|
|
delete [] thread_storage;
|
|
}
|
|
|
|
|
|
/*!
|
|
\class QThreadStorage
|
|
\brief The QThreadStorage class provides per-thread data storage.
|
|
|
|
\threadsafe
|
|
\ingroup thread
|
|
\ingroup environment
|
|
|
|
QThreadStorage is a template class that provides per-thread data
|
|
storage.
|
|
|
|
\e{Note that due to compiler limitations, QThreadStorage can only
|
|
store pointers.}
|
|
|
|
The setLocalData() function stores a single thread-specific value
|
|
for the calling thread. The data can be accessed later using the
|
|
localData() functions. QThreadStorage takes ownership of the
|
|
data (which must be created on the heap with \e new) and deletes
|
|
it when the thread exits (either normally or via termination).
|
|
|
|
The hasLocalData() function allows the programmer to determine if
|
|
data has previously been set using the setLocalData() function.
|
|
This is useful for lazy initializiation.
|
|
|
|
For example, the following code uses QThreadStorage to store a
|
|
single cache for each thread that calls the \e cacheObject() and
|
|
\e removeFromCache() functions. The cache is automatically
|
|
deleted when the calling thread exits (either normally or via
|
|
termination).
|
|
|
|
\code
|
|
QThreadStorage<QCache<SomeClass> *> caches;
|
|
|
|
void cacheObject( const QString &key, SomeClass *object )
|
|
{
|
|
if ( ! caches.hasLocalData() )
|
|
caches.setLocalData( new QCache<SomeClass> );
|
|
|
|
caches.localData()->insert( key, object );
|
|
}
|
|
|
|
void removeFromCache( const QString &key )
|
|
{
|
|
if ( ! caches.hasLocalData() )
|
|
return; // nothing to do
|
|
|
|
caches.localData()->remove( key );
|
|
}
|
|
\endcode
|
|
|
|
\section1 Caveats
|
|
|
|
\list
|
|
|
|
\i As noted above, QThreadStorage can only store pointers due to
|
|
compiler limitations. Support for value-based objects will be
|
|
added when the majority of compilers are able to support partial
|
|
template specialization.
|
|
|
|
\i The \link ~QThreadStorage() destructor\endlink does \e not
|
|
delete per-thread data. QThreadStorage only deletes per-thread
|
|
data when the thread exits or when setLocalData() is called
|
|
multiple times.
|
|
|
|
\i QThreadStorage can only be used with threads started with
|
|
QThread. It \e cannot be used with threads started with
|
|
platform-specific APIs.
|
|
|
|
\i As a corollary to the above, platform-specific APIs cannot be
|
|
used to exit or terminate a QThread using QThreadStorage. Doing so
|
|
will cause all per-thread data to be leaked. See QThread::exit()
|
|
and QThread::terminate().
|
|
|
|
\i QThreadStorage \e can be used to store data for the \e main()
|
|
thread \e after QApplication has been constructed. QThreadStorage
|
|
deletes all data set for the \e main() thread when QApplication is
|
|
destroyed, regardless of whether or not the \e main() thread has
|
|
actually finished.
|
|
|
|
\i The implementation of QThreadStorage limits the total number of
|
|
QThreadStorage objects to 256. An unlimited number of threads
|
|
can store per-thread data in each QThreadStorage object.
|
|
|
|
\endlist
|
|
*/
|
|
|
|
/*!
|
|
\fn QThreadStorage::QThreadStorage()
|
|
|
|
Constructs a new per-thread data storage object.
|
|
*/
|
|
|
|
/*!
|
|
\fn QThreadStorage::~QThreadStorage()
|
|
|
|
Destroys the per-thread data storage object.
|
|
|
|
Note: The per-thread data stored is \e not deleted. Any data left
|
|
in QThreadStorage is leaked. Make sure that all threads using
|
|
QThreadStorage have exited before deleting the QThreadStorage.
|
|
|
|
\sa hasLocalData()
|
|
*/
|
|
|
|
/*!
|
|
\fn bool QThreadStorage::hasLocalData() const
|
|
|
|
Returns TRUE if the calling thread has non-zero data available;
|
|
otherwise returns FALSE.
|
|
|
|
\sa localData()
|
|
*/
|
|
|
|
/*!
|
|
\fn T& QThreadStorage::localData()
|
|
|
|
Returns a reference to the data that was set by the calling
|
|
thread.
|
|
|
|
Note: QThreadStorage can only store pointers. This function
|
|
returns a \e reference to the pointer that was set by the calling
|
|
thread. The value of this reference is 0 if no data was set by
|
|
the calling thread,
|
|
|
|
\sa hasLocalData()
|
|
*/
|
|
/*
|
|
### addition to the above documentation when we start supporting
|
|
### partial template specialization, and QThreadStorage can store
|
|
### values *and* pointers
|
|
|
|
When using QThreadStorage to store values (not pointers), this
|
|
function stores an object of type \e T (created with its default
|
|
constructor) and returns a reference to that object.
|
|
*/
|
|
|
|
/*!
|
|
\fn const T QThreadStorage::localData() const
|
|
\overload
|
|
|
|
Returns a copy of the data that was set by the calling thread.
|
|
|
|
Note: QThreadStorage can only store pointers. This function
|
|
returns a pointer to the data that was set by the calling thread.
|
|
If no data was set by the calling thread, this function returns 0.
|
|
|
|
\sa hasLocalData()
|
|
*/
|
|
/*
|
|
### addition to the above documentation when we start supporting
|
|
### partial template specialization, and QThreadStorage can store
|
|
### values *and* pointers
|
|
|
|
When using QThreadStorage to store values (not pointers), this
|
|
function returns an object of type \e T (created with its default
|
|
constructor). Unlike the above function, this object is \e not
|
|
stored automatically. You will need to call setLocalData() to store
|
|
the object.
|
|
*/
|
|
|
|
/*!
|
|
\fn void QThreadStorage::setLocalData( T data )
|
|
|
|
Sets the local data for the calling thread to \a data. It can be
|
|
accessed later using the localData() functions.
|
|
|
|
If \a data is 0, this function deletes the previous data (if
|
|
any) and returns immediately.
|
|
|
|
If \a data is non-zero, QThreadStorage takes ownership of the \a
|
|
data and deletes it automatically either when the thread exits
|
|
(either normally or via termination) or when setLocalData() is
|
|
called again.
|
|
|
|
Note: QThreadStorage can only store pointers. The \a data
|
|
argument must be either a pointer to an object created on the heap
|
|
(i.e. using \e new) or 0. You should not delete \a data
|
|
yourself; QThreadStorage takes ownership and will delete the \a
|
|
data itself.
|
|
|
|
\sa localData() hasLocalData()
|
|
*/
|
|
|
|
#endif // QT_THREAD_SUPPORT
|