ActiveComponentBase.cpp

Go to the documentation of this file.

#include <Fw/Comp/ActiveComponentBase.hpp>
#include <Fw/FPrimeBasicTypes.hpp>
#include <Fw/Types/Assert.hpp>
#include <Os/TaskString.hpp>

namespace Fw {

class ActiveComponentExitSerializableBuffer : public Fw::LinearBufferBase {
  public:
    ActiveComponentExitSerializableBuffer() : Fw::LinearBufferBase(m_buff, sizeof(m_buff)) {}

  private:
    U8 m_buff[sizeof(ActiveComponentBase::ACTIVE_COMPONENT_EXIT)];
};

ActiveComponentBase::ActiveComponentBase(const char* name) : QueuedComponentBase(name), m_stage(Lifecycle::CREATED) {}

ActiveComponentBase::~ActiveComponentBase() {}

void ActiveComponentBase::init(FwEnumStoreType instance) {
    QueuedComponentBase::init(instance);
}

#if FW_OBJECT_TO_STRING == 1
const char* ActiveComponentBase::getToStringFormatString() {
    return "ActComp: %s";
}
#endif

void ActiveComponentBase::start(FwTaskPriorityType priority,
                                FwSizeType stackSize,
                                FwSizeType cpuAffinity,
                                FwTaskIdType identifier) {
    Os::TaskString taskName;

#if FW_OBJECT_NAMES == 1
    taskName = this->getObjName();
#else
    (void)taskName.format("ActComp_%" PRI_FwSizeType, Os::Task::getNumTasks());
#endif
    // Cooperative threads tasks externalize the task loop, and as such use the state machine as their task function
    // Standard multithreading tasks use the task loop to respectively call the state machine
    Os::Task::taskRoutine routine = (m_task.isCooperative()) ? this->s_taskStateMachine : this->s_taskLoop;
    Os::Task::Arguments arguments(taskName, routine, this, priority, stackSize, cpuAffinity, identifier);
    Os::Task::Status status = this->m_task.start(arguments);
    FW_ASSERT(status == Os::Task::Status::OP_OK, static_cast<FwAssertArgType>(status));
}

void ActiveComponentBase::exit() {
    ActiveComponentExitSerializableBuffer exitBuff;
    SerializeStatus stat = exitBuff.serializeFrom(static_cast<I32>(ACTIVE_COMPONENT_EXIT));
    FW_ASSERT(FW_SERIALIZE_OK == stat, static_cast<FwAssertArgType>(stat));
    (void)this->m_queue.send(exitBuff, 0, Os::Queue::BlockingType::NONBLOCKING);
}

Os::Task::Status ActiveComponentBase::join() {
    return this->m_task.join();
}

Os::Task::Status ActiveComponentBase::join(void** pointer) {
    return this->m_task.join();
}

void ActiveComponentBase::s_taskStateMachine(void* component_pointer) {
    FW_ASSERT(component_pointer != nullptr);
    // cast void* back to active component
    ActiveComponentBase* component = static_cast<ActiveComponentBase*>(component_pointer);

    // Each invocation of this function runs a single stage of the thread lifecycle. This has moved the thread
    // while loop to the top level such that it can be replaced by something else (e.g. cooperative thread
    // dispatcher) and is not intrinsic to this code.
    switch (component->m_stage) {
        // The first stage the active component triggers the "preamble" call before moving into the dispatching
        // stage of the component thread.
        case Lifecycle::CREATED:
            component->preamble();
            component->m_stage = Lifecycle::DISPATCHING;
            break;
        // The second stage of the active component triggers the dispatching loop dispatching messages until an
        // exit message is received.
        case Lifecycle::DISPATCHING:
            if (component->dispatch() == MsgDispatchStatus::MSG_DISPATCH_EXIT) {
                component->m_stage = Lifecycle::FINALIZING;
            }
            break;
        // The second-to-last stage is where the finalizer is called. This will transition to the final stage
        // automatically after the finalizer is called
        case Lifecycle::FINALIZING:
            component->finalizer();
            component->m_stage = Lifecycle::DONE;
            break;
        // The last stage does nothing, cooperative tasks live here forever, threaded tasks exit on this condition
        case Lifecycle::DONE:
            break;
        default:
            FW_ASSERT(false);
            break;
    }
}

void ActiveComponentBase::s_taskLoop(void* component_pointer) {
    FW_ASSERT(component_pointer != nullptr);
    ActiveComponentBase* component = static_cast<ActiveComponentBase*>(component_pointer);
    // A non-cooperative task switching implementation is just a while-loop around the active component
    // state-machine. Here the while loop is at top-level.
    // @non-terminating@: component lifecycle loop runs until DONE
    while (component->m_stage != ActiveComponentBase::Lifecycle::DONE) {
        ActiveComponentBase::s_taskStateMachine(component);
    }
}

ActiveComponentBase::MsgDispatchStatus ActiveComponentBase::dispatch() {
    // Cooperative tasks should return rather than block when no messages are available
    if (this->m_task.isCooperative() and m_queue.getMessagesAvailable() == 0) {
        return MsgDispatchStatus::MSG_DISPATCH_EMPTY;
    }
    return this->doDispatch();
}

void ActiveComponentBase::preamble() {}

void ActiveComponentBase::finalizer() {}

}  // namespace Fw