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QReadWriteLock: remove the private function from the symbol table

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Just move it to the private class. This also allows this function to get
inlined in QWaitCondition::wait().

Change-Id: I6f518d59e63249ddbf43fffd1759fc99c28c7ca8
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
(cherry picked from commit 0c0778fb36641efe73caa8776ee0a2ffdc98f4ea)
Reviewed-by: Ahmad Samir <a.samirh78@gmail.com>
This commit is contained in:
Thiago Macieira 2023-04-27 20:47:53 -07:00
parent e885a06390
commit ac111209f8
5 changed files with 56 additions and 41 deletions
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28
src/corelib/thread/qreadwritelock.cpp
View File

@ -6,9 +6,7 @@
#include "qplatformdefs.h"
#include "qreadwritelock.h"
#include "qmutex.h"
#include "qthread.h"
#include "qwaitcondition.h"
#include "qreadwritelock_p.h"
#include "qelapsedtimer.h"
#include "private/qfreelist_p.h"
@ -30,15 +28,11 @@ QT_BEGIN_NAMESPACE
* - In any other case, d_ptr points to an actual QReadWriteLockPrivate.
*/
using namespace QReadWriteLockStates;
namespace {
using ms = std::chrono::milliseconds;
enum {
StateMask = 0x3,
StateLockedForRead = 0x1,
StateLockedForWrite = 0x2,
};
const auto dummyLockedForRead = reinterpret_cast<QReadWriteLockPrivate *>(quintptr(StateLockedForRead));
const auto dummyLockedForWrite = reinterpret_cast<QReadWriteLockPrivate *>(quintptr(StateLockedForWrite));
inline bool isUncontendedLocked(const QReadWriteLockPrivate *d)
@ -411,26 +405,6 @@ void QReadWriteLock::unlock()
}
}
/*! \internal Helper for QWaitCondition::wait */
QReadWriteLock::StateForWaitCondition QReadWriteLock::stateForWaitCondition() const
{
QReadWriteLockPrivate *d = d_ptr.loadAcquire();
switch (quintptr(d) & StateMask) {
case StateLockedForRead: return LockedForRead;
case StateLockedForWrite: return LockedForWrite;
}
if (!d)
return Unlocked;
const auto lock = qt_scoped_lock(d->mutex);
if (d->writerCount > 1)
return RecursivelyLocked;
else if (d->writerCount == 1)
return LockedForWrite;
return LockedForRead;
}
bool QReadWriteLockPrivate::lockForRead(std::unique_lock<QtPrivate::mutex> &lock, int timeout)
{
Q_ASSERT(!mutex.try_lock()); // mutex must be locked when entering this function

5
src/corelib/thread/qreadwritelock.h
View File

@ -34,10 +34,7 @@ public:
private:
Q_DISABLE_COPY(QReadWriteLock)
QAtomicPointer<QReadWriteLockPrivate> d_ptr;
enum StateForWaitCondition { LockedForRead, LockedForWrite, Unlocked, RecursivelyLocked };
StateForWaitCondition stateForWaitCondition() const;
friend class QWaitCondition;
friend class QReadWriteLockPrivate;
};
#if defined(Q_CC_MSVC)

44
src/corelib/thread/qreadwritelock_p.h
View File

@ -16,14 +16,29 @@
// We mean it.
//
#include <QtCore/private/qglobal_p.h>
#include <QtCore/private/qlocking_p.h>
#include <QtCore/private/qwaitcondition_p.h>
#include <QtCore/qreadwritelock.h>
#include <QtCore/qvarlengtharray.h>
QT_REQUIRE_CONFIG(thread);
QT_BEGIN_NAMESPACE
namespace QReadWriteLockStates {
enum {
StateMask = 0x3,
StateLockedForRead = 0x1,
StateLockedForWrite = 0x2,
};
enum StateForWaitCondition {
LockedForRead,
LockedForWrite,
Unlocked,
RecursivelyLocked
};
}
class QReadWriteLockPrivate
{
public:
@ -63,8 +78,33 @@ public:
bool recursiveLockForWrite(int timeout);
bool recursiveLockForRead(int timeout);
void recursiveUnlock();
static QReadWriteLockStates::StateForWaitCondition
stateForWaitCondition(const QReadWriteLock *lock);
};
Q_DECLARE_TYPEINFO(QReadWriteLockPrivate::Reader, Q_PRIMITIVE_TYPE);
Q_DECLARE_TYPEINFO(QReadWriteLockPrivate::Reader, Q_PRIMITIVE_TYPE);\
/*! \internal Helper for QWaitCondition::wait */
inline QReadWriteLockStates::StateForWaitCondition
QReadWriteLockPrivate::stateForWaitCondition(const QReadWriteLock *q)
{
using namespace QReadWriteLockStates;
QReadWriteLockPrivate *d = q->d_ptr.loadAcquire();
switch (quintptr(d) & StateMask) {
case StateLockedForRead: return LockedForRead;
case StateLockedForWrite: return LockedForWrite;
}
if (!d)
return Unlocked;
const auto lock = qt_scoped_lock(d->mutex);
if (d->writerCount > 1)
return RecursivelyLocked;
else if (d->writerCount == 1)
return LockedForWrite;
return LockedForRead;
}
QT_END_NAMESPACE

10
src/corelib/thread/qwaitcondition_unix.cpp
View File

@ -173,12 +173,14 @@ bool QWaitCondition::wait(QReadWriteLock *readWriteLock, unsigned long time)
bool QWaitCondition::wait(QReadWriteLock *readWriteLock, QDeadlineTimer deadline)
{
using namespace QReadWriteLockStates;
if (!readWriteLock)
return false;
auto previousState = readWriteLock->stateForWaitCondition();
if (previousState == QReadWriteLock::Unlocked)
auto previousState = QReadWriteLockPrivate::stateForWaitCondition(readWriteLock);
if (previousState == Unlocked)
return false;
if (previousState == QReadWriteLock::RecursivelyLocked) {
if (previousState == RecursivelyLocked) {
qWarning("QWaitCondition: cannot wait on QReadWriteLocks with recursive lockForWrite()");
return false;
}
@ -190,7 +192,7 @@ bool QWaitCondition::wait(QReadWriteLock *readWriteLock, QDeadlineTimer deadline
bool returnValue = d->wait(deadline);
if (previousState == QReadWriteLock::LockedForWrite)
if (previousState == LockedForWrite)
readWriteLock->lockForWrite();
else
readWriteLock->lockForRead();

10
src/corelib/thread/qwaitcondition_win.cpp
View File

@ -145,12 +145,14 @@ bool QWaitCondition::wait(QMutex *mutex, QDeadlineTimer deadline)
bool QWaitCondition::wait(QReadWriteLock *readWriteLock, unsigned long time)
{
using namespace QReadWriteLockStates;
if (!readWriteLock)
return false;
auto previousState = readWriteLock->stateForWaitCondition();
if (previousState == QReadWriteLock::Unlocked)
auto previousState = QReadWriteLockPrivate::stateForWaitCondition(readWriteLock);
if (previousState == Unlocked)
return false;
if (previousState == QReadWriteLock::RecursivelyLocked) {
if (previousState == RecursivelyLocked) {
qWarning("QWaitCondition: cannot wait on QReadWriteLocks with recursive lockForWrite()");
return false;
}
@ -160,7 +162,7 @@ bool QWaitCondition::wait(QReadWriteLock *readWriteLock, unsigned long time)
bool returnValue = d->wait(wce, time);
if (previousState == QReadWriteLock::LockedForWrite)
if (previousState == LockedForWrite)
readWriteLock->lockForWrite();
else
readWriteLock->lockForRead();