diff options
| -rw-r--r-- | src/libcamera/base/object.cpp | 14 | ||||
| -rw-r--r-- | src/libcamera/base/signal.cpp | 7 | ||||
| -rw-r--r-- | test/signal.cpp | 17 |
3 files changed, 29 insertions, 9 deletions
diff --git a/src/libcamera/base/object.cpp b/src/libcamera/base/object.cpp index 3f28768e..ec5b55d1 100644 --- a/src/libcamera/base/object.cpp +++ b/src/libcamera/base/object.cpp @@ -47,6 +47,14 @@ LOG_DEFINE_CATEGORY(Object) * object's thread, regardless of whether the signal is emitted in the same or * in another thread. * + * Objects can be connected to multiple signals, but they can only be connected + * to each signal once. Attempting to create multiple concurrent connections + * between the same signal and the same Object (to either the same or differents + * slots of the object) will cause an assertion failure. While it would be + * possible to allow the implementation to let objects connect to the same + * signal multiple times, there are no expected use cases for this in libcamera + * and this behaviour is restricted to favour defensive programming. + * * \sa Message, Signal, Thread */ @@ -284,6 +292,12 @@ void Object::notifyThreadMove() void Object::connect(SignalBase *signal) { + /* + * Connecting the same signal to an object multiple times is not + * supported. + */ + ASSERT(std::find(signals_.begin(), signals_.end(), signal) == signals_.end()); + signals_.push_back(signal); } diff --git a/src/libcamera/base/signal.cpp b/src/libcamera/base/signal.cpp index 9df45d07..a46386a0 100644 --- a/src/libcamera/base/signal.cpp +++ b/src/libcamera/base/signal.cpp @@ -93,9 +93,7 @@ SignalBase::SlotList SignalBase::slots() * Connecting a signal to a slot results in the slot being called with the * arguments passed to the emit() function when the signal is emitted. Multiple * slots can be connected to the same signal, and multiple signals can connected - * to the same slot. Duplicate connections between a signal and a slot are - * allowed and result in the slot being called multiple times for the same - * signal emission. + * to the same slot. * * When a slot belongs to an instance of the Object class, the slot is called * in the context of the thread that the object is bound to. If the signal is @@ -105,6 +103,9 @@ SignalBase::SlotList SignalBase::slots() * loop, after the Signal::emit() function returns, with a copy of the signal's * arguments. The emitter shall thus ensure that any pointer or reference * passed through the signal will remain valid after the signal is emitted. + * + * Duplicate connections between a signal and a slot are not expected and use of + * the Object class to manage signals will enforce this restriction. */ /** diff --git a/test/signal.cpp b/test/signal.cpp index fcf2def1..5c6b304d 100644 --- a/test/signal.cpp +++ b/test/signal.cpp @@ -212,17 +212,19 @@ protected: /* ----------------- Signal -> Object tests ----------------- */ /* - * Test automatic disconnection on object deletion. Connect the - * slot twice to ensure all instances are disconnected. + * Test automatic disconnection on object deletion. Connect two + * signals to ensure all instances are disconnected. */ signalVoid_.disconnect(); + signalVoid2_.disconnect(); SlotObject *slotObject = new SlotObject(); signalVoid_.connect(slotObject, &SlotObject::slot); - signalVoid_.connect(slotObject, &SlotObject::slot); + signalVoid2_.connect(slotObject, &SlotObject::slot); delete slotObject; valueStatic_ = 0; signalVoid_.emit(); + signalVoid2_.emit(); if (valueStatic_ != 0) { cout << "Signal disconnection on object deletion test failed" << endl; return TestFail; @@ -298,17 +300,19 @@ protected: /* --------- Signal -> Object (multiple inheritance) -------- */ /* - * Test automatic disconnection on object deletion. Connect the - * slot twice to ensure all instances are disconnected. + * Test automatic disconnection on object deletion. Connect two + * signals to ensure all instances are disconnected. */ signalVoid_.disconnect(); + signalVoid2_.disconnect(); SlotMulti *slotMulti = new SlotMulti(); signalVoid_.connect(slotMulti, &SlotMulti::slot); - signalVoid_.connect(slotMulti, &SlotMulti::slot); + signalVoid2_.connect(slotMulti, &SlotMulti::slot); delete slotMulti; valueStatic_ = 0; signalVoid_.emit(); + signalVoid2_.emit(); if (valueStatic_ != 0) { cout << "Signal disconnection on object deletion test failed" << endl; return TestFail; @@ -345,6 +349,7 @@ protected: private: Signal<> signalVoid_; + Signal<> signalVoid2_; Signal<int> signalInt_; Signal<int, const std::string &> signalMultiArgs_; |