Method clear

async_simple/Signal.h:239–260

Clear the signal handler. If return false, it indicates that the signal handler has been executed or handler is empty

    // Clear the signal handler. If return false, it indicates
    // that the signal handler has been executed or handler is empty
    bool clear(SignalType type) {
        logicAssert(std::popcount(static_cast<uint64_t>(type)) == 1,
                    "It's not allow to emplace for multiple signals");
        auto oldHandlerPtr = loadHandler<false>(type);
        if (oldHandlerPtr == nullptr) {
            return false;
        }
        auto oldHandler = oldHandlerPtr->load(std::memory_order_acquire);
        if (oldHandler ==
                &detail::SignalSlotSharedState::HandlerManager::emittedTag ||
            oldHandler == nullptr) {
            return false;
        }
        if (!oldHandlerPtr->compare_exchange_strong(
                oldHandler, nullptr, std::memory_order_release)) {
            assert(oldHandler ==
                   &detail::SignalSlotSharedState::HandlerManager::emittedTag);
            return false;
        }
        delete oldHandler;
        return true;
    }

    class FilterGuard {
        friend class Slot;