core: correctly deregister QML incubators on destruction

Previously we'd try to cast the QObject* sender from
QObject::destroyed to a QQmlIncubationController*. This will always
return nullptr because C++ destructors change the type of the object
and the QQmlIncubationController destructor has already run at this
point. We now store controllers as QObject*s.

Fixes #108
This commit is contained in:
outfoxxed 2025-07-11 00:38:58 -07:00
parent 026aac3756
commit 49a3752b9d
Signed by untrusted user: outfoxxed
GPG key ID: 4C88A185FB89301E
2 changed files with 30 additions and 34 deletions

View file

@ -11,6 +11,7 @@
#include <qlist.h>
#include <qlogging.h>
#include <qloggingcategory.h>
#include <qnamespace.h>
#include <qobject.h>
#include <qqmlcontext.h>
#include <qqmlengine.h>
@ -238,23 +239,24 @@ void EngineGeneration::onDirectoryChanged() {
void EngineGeneration::registerIncubationController(QQmlIncubationController* controller) {
// We only want controllers that we can swap out if destroyed.
// This happens if the window owning the active controller dies.
if (auto* obj = dynamic_cast<QObject*>(controller)) {
QObject::connect(
obj,
&QObject::destroyed,
this,
&EngineGeneration::incubationControllerDestroyed
);
} else {
auto* obj = dynamic_cast<QObject*>(controller);
if (!obj) {
qCWarning(logIncubator) << "Could not register incubation controller as it is not a QObject"
<< controller;
return;
}
this->incubationControllers.push_back(controller);
qCDebug(logIncubator) << "Registered incubation controller" << controller << "to generation"
<< this;
QObject::connect(
obj,
&QObject::destroyed,
this,
&EngineGeneration::incubationControllerDestroyed,
Qt::UniqueConnection
);
this->incubationControllers.push_back(obj);
qCDebug(logIncubator) << "Registered incubation controller" << obj << "to generation" << this;
// This function can run during destruction.
if (this->engine == nullptr) return;
@ -264,21 +266,25 @@ void EngineGeneration::registerIncubationController(QQmlIncubationController* co
}
}
// Multiple controllers may be destroyed at once. Dynamic casts must be performed before working
// with any controllers. The QQmlIncubationController destructor will already have run by the
// point QObject::destroyed is called, so we can't cast to that.
void EngineGeneration::deregisterIncubationController(QQmlIncubationController* controller) {
if (auto* obj = dynamic_cast<QObject*>(controller)) {
QObject::disconnect(obj, nullptr, this, nullptr);
} else {
auto* obj = dynamic_cast<QObject*>(controller);
if (!obj) {
qCCritical(logIncubator) << "Deregistering incubation controller which is not a QObject, "
"however only QObject controllers should be registered.";
}
if (!this->incubationControllers.removeOne(controller)) {
qCCritical(logIncubator) << "Failed to deregister incubation controller" << controller << "from"
QObject::disconnect(obj, nullptr, this, nullptr);
if (this->incubationControllers.removeOne(obj)) {
qCDebug(logIncubator) << "Deregistered incubation controller" << obj << "from" << this;
} else {
qCCritical(logIncubator) << "Failed to deregister incubation controller" << obj << "from"
<< this << "as it was not registered to begin with";
qCCritical(logIncubator) << "Current registered incuabation controllers"
<< this->incubationControllers;
} else {
qCDebug(logIncubator) << "Deregistered incubation controller" << controller << "from" << this;
}
// This function can run during destruction.
@ -293,22 +299,12 @@ void EngineGeneration::deregisterIncubationController(QQmlIncubationController*
void EngineGeneration::incubationControllerDestroyed() {
auto* sender = this->sender();
auto* controller = dynamic_cast<QQmlIncubationController*>(sender);
if (controller == nullptr) {
qCCritical(logIncubator) << "Destroyed incubation controller" << sender << "is not known to"
<< this << ", this may cause memory corruption";
qCCritical(logIncubator) << "Current registered incuabation controllers"
<< this->incubationControllers;
return;
}
if (this->incubationControllers.removeOne(controller)) {
qCDebug(logIncubator) << "Destroyed incubation controller" << controller << "deregistered from"
if (this->incubationControllers.removeAll(sender) != 0) {
qCDebug(logIncubator) << "Destroyed incubation controller" << sender << "deregistered from"
<< this;
} else {
qCCritical(logIncubator) << "Destroyed incubation controller" << controller
qCCritical(logIncubator) << "Destroyed incubation controller" << sender
<< "was not registered, but its destruction was observed by" << this;
return;
@ -317,7 +313,7 @@ void EngineGeneration::incubationControllerDestroyed() {
// This function can run during destruction.
if (this->engine == nullptr) return;
if (this->engine->incubationController() == controller) {
if (dynamic_cast<QObject*>(this->engine->incubationController()) == sender) {
qCDebug(logIncubator
) << "Destroyed incubation controller was currently active, reassigning from pool";
this->assignIncubationController();
@ -371,7 +367,7 @@ void EngineGeneration::assignIncubationController() {
if (this->incubationControllersLocked || this->incubationControllers.isEmpty()) {
controller = &this->delayedIncubationController;
} else {
controller = this->incubationControllers.first();
controller = dynamic_cast<QQmlIncubationController*>(this->incubationControllers.first());
}
qCDebug(logIncubator) << "Assigning incubation controller" << controller << "to generation"

View file

@ -89,7 +89,7 @@ private slots:
private:
void postReload();
void assignIncubationController();
QVector<QQmlIncubationController*> incubationControllers;
QVector<QObject*> incubationControllers;
bool incubationControllersLocked = false;
QHash<const void*, EngineGenerationExt*> extensions;