@@ -13,9 +13,10 @@
namespace libcamera {
class Message;
-class SignalBase;
template<typename... Args>
class Signal;
+class SignalBase;
+class SlotBase;
class Thread;
class Object
@@ -33,6 +34,7 @@ public:
private:
template<typename... Args>
friend class Signal;
+ friend class SlotBase;
friend class Thread;
void connect(SignalBase *signal);
@@ -18,23 +18,28 @@ namespace libcamera {
template<typename... Args>
class Signal;
+class SignalBase;
class SlotBase
{
public:
- SlotBase(void *obj, bool isObject)
- : obj_(obj), isObject_(isObject) {}
+ SlotBase(void *obj, Object *object)
+ : obj_(obj), object_(object) {}
virtual ~SlotBase() {}
- void *obj() { return obj_; }
- bool isObject() const { return isObject_; }
+ template<typename T>
+ bool match(T *obj) { return obj == obj_; }
+ template<>
+ bool match(Object *object) { return object == object_; }
+
+ void disconnect(SignalBase *signal);
void activatePack(void *pack);
virtual void invokePack(void *pack) = 0;
protected:
void *obj_;
- bool isObject_;
+ Object *object_;
};
template<typename... Args>
@@ -71,8 +76,8 @@ private:
}
public:
- SlotArgs(void *obj, bool isObject)
- : SlotBase(obj, isObject) {}
+ SlotArgs(void *obj, Object *object)
+ : SlotBase(obj, object) {}
void invokePack(void *pack) override
{
@@ -89,12 +94,12 @@ class SlotMember : public SlotArgs<Args...>
public:
using PackType = std::tuple<typename std::remove_reference<Args>::type...>;
- SlotMember(T *obj, bool isObject, void (T::*func)(Args...))
- : SlotArgs<Args...>(obj, isObject), func_(func) {}
+ SlotMember(T *obj, Object *object, void (T::*func)(Args...))
+ : SlotArgs<Args...>(obj, object), func_(func) {}
void activate(Args... args)
{
- if (this->isObject_)
+ if (this->object_)
SlotBase::activatePack(new PackType{ args... });
else
(static_cast<T *>(this->obj_)->*func_)(args...);
@@ -115,7 +120,7 @@ class SlotStatic : public SlotArgs<Args...>
{
public:
SlotStatic(void (*func)(Args...))
- : SlotArgs<Args...>(nullptr, false), func_(func) {}
+ : SlotArgs<Args...>(nullptr, nullptr), func_(func) {}
void activate(Args... args) { (*func_)(args...); }
void invoke(Args... args) {}
@@ -129,11 +134,11 @@ class SignalBase
{
public:
template<typename T>
- void disconnect(T *object)
+ void disconnect(T *obj)
{
for (auto iter = slots_.begin(); iter != slots_.end(); ) {
SlotBase *slot = *iter;
- if (slot->obj() == object) {
+ if (slot->match(obj)) {
iter = slots_.erase(iter);
delete slot;
} else {
@@ -155,27 +160,27 @@ public:
~Signal()
{
for (SlotBase *slot : slots_) {
- if (slot->isObject())
- static_cast<Object *>(slot->obj())->disconnect(this);
+ slot->disconnect(this);
delete slot;
}
}
#ifndef __DOXYGEN__
template<typename T, typename std::enable_if<std::is_base_of<Object, T>::value>::type * = nullptr>
- void connect(T *object, void (T::*func)(Args...))
+ void connect(T *obj, void (T::*func)(Args...))
{
+ Object *object = static_cast<Object *>(obj);
object->connect(this);
- slots_.push_back(new SlotMember<T, Args...>(object, true, func));
+ slots_.push_back(new SlotMember<T, Args...>(obj, object, func));
}
template<typename T, typename std::enable_if<!std::is_base_of<Object, T>::value>::type * = nullptr>
#else
template<typename T>
#endif
- void connect(T *object, void (T::*func)(Args...))
+ void connect(T *obj, void (T::*func)(Args...))
{
- slots_.push_back(new SlotMember<T, Args...>(object, false, func));
+ slots_.push_back(new SlotMember<T, Args...>(obj, nullptr, func));
}
void connect(void (*func)(Args...))
@@ -191,23 +196,23 @@ public:
}
template<typename T>
- void disconnect(T *object)
+ void disconnect(T *obj)
{
- SignalBase::disconnect(object);
+ SignalBase::disconnect(obj);
}
template<typename T>
- void disconnect(T *object, void (T::*func)(Args...))
+ void disconnect(T *obj, void (T::*func)(Args...))
{
for (auto iter = slots_.begin(); iter != slots_.end(); ) {
SlotArgs<Args...> *slot = static_cast<SlotArgs<Args...> *>(*iter);
/*
- * If the obj() pointer matches the object, the slot is
+ * If the object matches the slot, the slot is
* guaranteed to be a member slot, so we can safely
* cast it to SlotMember<T, Args...> and access its
* func_ member.
*/
- if (slot->obj() == object &&
+ if (slot->match(obj) &&
static_cast<SlotMember<T, Args...> *>(slot)->func_ == func) {
iter = slots_.erase(iter);
delete slot;
@@ -221,7 +226,7 @@ public:
{
for (auto iter = slots_.begin(); iter != slots_.end(); ) {
SlotArgs<Args...> *slot = *iter;
- if (slot->obj() == nullptr &&
+ if (slot->match(nullptr) &&
static_cast<SlotStatic<Args...> *>(slot)->func_ == func) {
iter = slots_.erase(iter);
delete slot;
@@ -57,9 +57,15 @@ namespace libcamera {
* passed through the signal will remain valid after the signal is emitted.
*/
+void SlotBase::disconnect(SignalBase *signal)
+{
+ if (object_)
+ object_->disconnect(signal);
+}
+
void SlotBase::activatePack(void *pack)
{
- Object *obj = static_cast<Object *>(obj_);
+ Object *obj = static_cast<Object *>(object_);
if (Thread::current() == obj->thread()) {
invokePack(pack);
The SlotBase implementation stores the receiver object pointer as a void pointer internally. The pointer is then cast back to an Object pointer when the receiver object class derives from Object. When the receiver is an object that inherits from both the Object class and other classes, the Object data members may not be stored at the beginning of the object memory. The cast back to an Object pointer is thus incorrect. Fix this by casting the receiver object pointer to an Object pointer where the type of the receiver object is known, and pass it along with the receiver void pointer to the SlotBase class. The SlotBase class stores both pointers internally, and doesn't need the isObject_ field anymore as the same information is obtained from checking if the Object pointer is null. To avoid confusing the two pointers, use the same naming scheme through the whole implementation: "obj" points to a receiver object as an unknown type, and "object" to the receiver object cast to an Object. The latter is null when the receiver object doesn't inherit from the Object class. To further clarify the code, remove direct access to the SlotBase "obj" and "object" fields as much as possible. They are replaced by two new methods : - SlotBase::disconnect() to disconnect a signal from the slot's receiver object - SlotBase::match() to test if an object pointer matches the slot The match() method is a template method with a specialisation for the Object type, to compare either the obj or the object pointer depending on the type of the parameter. This is required as the Object destructor calls the SignalBase::disconnect() method for signal connected to the object, and passes a pointer to Object to that method, while the actual object may have a different address due to the issue explained above. The pointer must thus be compared with the stored Object pointer in that case, not to the pointer to the receiver object. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> --- include/libcamera/object.h | 4 ++- include/libcamera/signal.h | 55 +++++++++++++++++++++----------------- src/libcamera/signal.cpp | 8 +++++- 3 files changed, 40 insertions(+), 27 deletions(-)