libpyside: Reimplement signal connections for Python callables not targeting a QMetaMethod

The code previously used a instances of class GlobalReceiverV2 inheriting QObject in a hash in
SignalManager per slot tracking the list of senders to be able to use standard signal/slot
connections in Qt. This was a complicated data structure and had issues with cleanups.

This has been replaced by using an invoker object based on QtPrivate::QSlotObjectBase which
can be passed to
QObjectPrivate::connect(const QObject *, int signal, QtPrivate::QSlotObjectBase *, ...).

The connections (identified by ConnectionKey) are now stored in a hash with QMetaObject::Connection
as value, which can be used to disconnect using QObject::disconnect(QMetaObject::Connection).

Deletion tracking is done by using signal QObject::destroyed(QObject*) which requires
adapting some tests checking on the connection count and weak ref notification on receivers
as was the case before.

[ChangeLog][PySide6] Signal connections for Python callables not targeting a QMetaMethod
has be reimplemented to simplify code and prepare for removal of the GIL.

Task-number: PYSIDE-2810
Task-number: PYSIDE-2221
Change-Id: Ib55e73d4d7bfe6d7a8b7adc3ce3734eac5789bea
Reviewed-by: Shyamnath Premnadh <Shyamnath.Premnadh@qt.io>
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>

1 files changed, 0 insertions, 180 deletions

diff --git a/sources/pyside6/libpyside/globalreceiverv2.cpp b/sources/pyside6/libpyside/globalreceiverv2.cpp
deleted file mode 100644
index 41ed35263..000000000
--- a/sources/pyside6/libpyside/globalreceiverv2.cpp
+++ /dev/null
@@ -1,180 +0,0 @@
-// Copyright (C) 2016 The Qt Company Ltd.
-// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
-
-#include "globalreceiverv2.h"
-#include "dynamicslot_p.h"
-#include "pysideweakref.h"
-#include "pysidestaticstrings.h"
-#include "pysideutils.h"
-#include "signalmanager.h"
-
-#include <autodecref.h>
-#include <gilstate.h>
-#include <pep384ext.h>
-
-#include <QtCore/QMetaMethod>
-#include <QtCore/QSet>
-#include <QtCore/QDebug>
-
-#include <cstring>
-#include <utility>
-
-namespace PySide
-{
-
-GlobalReceiverKey GlobalReceiverV2::key(PyObject *callback)
-{
-    Shiboken::GilState gil;
-    switch (DynamicSlot::slotType(callback)) {
-    case DynamicSlot::SlotType::Method:
-        // PYSIDE-1422: Avoid hash on self which might be unhashable.
-        return {PyMethod_GET_SELF(callback), PyMethod_GET_FUNCTION(callback)};
-    case DynamicSlot::SlotType::CompiledMethod: {
-        // PYSIDE-1589: Fix for slots in compiled functions
-        Shiboken::AutoDecRef self(PyObject_GetAttr(callback, PySide::PySideName::im_self()));
-        Shiboken::AutoDecRef func(PyObject_GetAttr(callback, PySide::PySideName::im_func()));
-        return {self, func};
-    }
-    case DynamicSlot::SlotType::Callable:
-        break;
-    }
-    return {nullptr, callback};
-}
-
-const char *GlobalReceiverV2::senderDynamicProperty = "_q_pyside_sender";
-
-GlobalReceiverV2::GlobalReceiverV2(PyObject *callback, QObject *receiver) :
-    QObject(nullptr),
-    m_metaObject("__GlobalReceiver__", &QObject::staticMetaObject),
-    m_data(DynamicSlot::create(callback, this)),
-    m_receiver(receiver)
-{
-}
-
-GlobalReceiverV2::~GlobalReceiverV2()
-{
-    m_refs.clear();
-    // Remove itself from map.
-    // Suppress handling of destroyed() for objects whose last reference is contained inside
-    // the callback object that will now be deleted. The reference could be a default argument,
-    // a callback local variable, etc.
-    // The signal has to be suppressed because it would lead to the following situation:
-    // Callback is deleted, hence the last reference is decremented,
-    // leading to the object being deleted, which emits destroyed(), which would try to invoke
-    // the already deleted callback, and also try to delete the object again.
-    delete std::exchange(m_data, nullptr);
-}
-
-int GlobalReceiverV2::addSlot(const QByteArray &signature)
-{
-    auto it = m_signatures.find(signature);
-    if (it == m_signatures.end()) {
-        const int index = metaObjectBuilder().addSlot(signature);
-        it = m_signatures.insert(signature, index);
-    }
-    return it.value();
-}
-
-void GlobalReceiverV2::incRef(const QObject *link)
-{
-    Q_ASSERT(link);
-    m_refs.append(link);
-}
-
-void GlobalReceiverV2::decRef(const QObject *link)
-{
-    Q_ASSERT(link);
-    m_refs.removeOne(link);
-}
-
-void GlobalReceiverV2::notify()
-{
-    purgeDeletedSenders();
-}
-
-static bool isNull(const QPointer<const QObject> &p)
-{
-    return p.isNull();
-}
-
-void GlobalReceiverV2::purgeDeletedSenders()
-{
-    m_refs.erase(std::remove_if(m_refs.begin(), m_refs.end(), isNull), m_refs.end());
-}
-
-bool GlobalReceiverV2::isEmpty() const
-{
-    return std::all_of(m_refs.cbegin(), m_refs.cend(), isNull);
-}
-
-const QMetaObject *GlobalReceiverV2::metaObject() const
-{
-    return const_cast<GlobalReceiverV2 *>(this)->m_metaObject.update();
-}
-
-int GlobalReceiverV2::qt_metacall(QMetaObject::Call call, int id, void **args)
-{
-    Shiboken::GilState gil;
-    Q_ASSERT(call == QMetaObject::InvokeMetaMethod);
-    Q_ASSERT(id >= QObject::staticMetaObject.methodCount());
-
-    QMetaMethod slot = metaObject()->method(id);
-    Q_ASSERT(slot.methodType() == QMetaMethod::Slot);
-
-    if (!m_data) {
-        const QByteArray message = "PySide6 Warning: Skipping callback call "
-            + slot.methodSignature() + " because the callback object is being destructed.";
-        PyErr_WarnEx(PyExc_RuntimeWarning, message.constData(), 0);
-        return -1;
-    }
-
-    const bool setSenderDynamicProperty = !m_receiver.isNull();
-    if (setSenderDynamicProperty)
-        m_receiver->setProperty(senderDynamicProperty, QVariant::fromValue(sender()));
-
-    m_data->call(slot.parameterTypes(), slot.typeName(), args);
-
-    if (setSenderDynamicProperty)
-        m_receiver->setProperty(senderDynamicProperty, QVariant{});
-
-    // SignalManager::callPythonMetaMethod might have failed, in that case we have to print the
-    // error so it considered "handled".
-    if (PyErr_Occurred()) {
-        int reclimit = Py_GetRecursionLimit();
-        // Inspired by Python's errors.c: PyErr_GivenExceptionMatches() function.
-        // Temporarily bump the recursion limit, so that PyErr_Print will not raise a recursion
-        // error again. Don't do it when the limit is already insanely high, to avoid overflow.
-        if (reclimit < (1 << 30))
-            Py_SetRecursionLimit(reclimit + 5);
-        PyErr_Print();
-        Py_SetRecursionLimit(reclimit);
-    }
-
-    return -1;
-}
-
-void GlobalReceiverV2::formatDebug(QDebug &debug) const
-{
-    debug << "receiver=" << m_receiver
-        << ", signatures=" << m_signatures.keys() << ", slot=" << m_data;
-    if (isEmpty())
-        debug << ", empty";
-    else
-        debug << ", refs=" << m_refs;
-};
-
-QDebug operator<<(QDebug debug, const GlobalReceiverV2 *g)
-{
-    QDebugStateSaver saver(debug);
-    debug.noquote();
-    debug.nospace();
-    debug << "GlobalReceiverV2(";
-    if (g)
-        g->formatDebug(debug);
-    else
-        debug << '0';
-    debug << ')';
-    return debug;
-}
-
-} // namespace PySide