qf_actq.cpp

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//============================================================================
// QP/C++ Real-Time Event Framework (RTEF)
//
// Copyright (C) 2005 Quantum Leaps, LLC. All rights reserved.
//
//                    Q u a n t u m  L e a P s
//                    ------------------------
//                    Modern Embedded Software
//
// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-QL-commercial
//
// This software is dual-licensed under the terms of the open-source GNU
// General Public License (GPL) or under the terms of one of the closed-
// source Quantum Leaps commercial licenses.
//
// Redistributions in source code must retain this top-level comment block.
// Plagiarizing this software to sidestep the license obligations is illegal.
//
// NOTE:
// The GPL does NOT permit the incorporation of this code into proprietary
// programs. Please contact Quantum Leaps for commercial licensing options,
// which expressly supersede the GPL and are designed explicitly for
// closed-source distribution.
//
// Quantum Leaps contact information:
// <www.state-machine.com/licensing>
// <info@state-machine.com>
//============================================================================
#define QP_IMPL             // this is QP implementation
#include "qp_port.hpp"      // QP port
#include "qp_pkg.hpp"       // QP package-scope interface
#include "qsafe.h"          // QP Functional Safety (FuSa) Subsystem
#ifdef Q_SPY                // QS software tracing enabled?
    #include "qs_port.hpp"  // QS port
    #include "qs_pkg.hpp"   // QS facilities for pre-defined trace records
#else
    #include "qs_dummy.hpp" // disable the QS software tracing
#endif // Q_SPY
 
//============================================================================
// unnamed namespace for local definitions with internal linkage
namespace {
Q_DEFINE_THIS_MODULE("qf_actq")
} // unnamed namespace
 
namespace QP {
 
//............................................................................
bool QActive::post_(
    QEvt const * const e,
    std::uint_fast16_t const margin,
    void const * const sender) noexcept
{
#ifndef Q_SPY
    Q_UNUSED_PAR(sender);
#endif
 
#ifdef Q_UTEST // test?
#if (Q_UTEST != 0) // testing QP-stub?
    if (m_temp.fun == Q_STATE_CAST(0)) { // QActiveDummy?
        return static_cast<QActiveDummy *>(this)->fakePost(e, margin, sender);
    }
#endif // (Q_UTEST != 0)
#endif // def Q_UTEST
 
    QF_CRIT_STAT
    QF_CRIT_ENTRY();
 
    Q_REQUIRE_INCRIT(200, e != nullptr);
 
    QEQueueCtr const nFree = m_eQueue.m_nFree; // get volatile into temporary
 
    // required margin available?
    bool status = false; // assume that event cannot be posted
    if (margin == QF::NO_MARGIN) {
        if (nFree > 0U) { // free entries available in the queue?
            status = true; // can post
        }
        else { // no free entries available
            // The queue overflows, but QF_NO_MARGIN indicates that
            // the "event delivery guarantee" is required.
            Q_ERROR_INCRIT(210); // must be able to post the event
        }
    }
    else if (nFree > static_cast<QEQueueCtr>(margin)) { // enough free?
        status = true; // can post
    }
    else {
        // empty
    }
 
#if (QF_MAX_EPOOL > 0U)
    if (e->poolNum_ != 0U) { // is it a mutable event?
        Q_ASSERT_INCRIT(205, e->refCtr_ < (2U * QF_MAX_ACTIVE));
        QEvt_refCtr_inc_(e); // increment the reference counter
    }
#endif // (QF_MAX_EPOOL > 0U)
 
    if (status) { // can post the event?
        postFIFO_(e, sender);
        QF_CRIT_EXIT();
    }
    else { // event cannot be posted
        QS_BEGIN_PRE(QS_QF_ACTIVE_POST_ATTEMPT, m_prio)
            QS_TIME_PRE();       // timestamp
            QS_OBJ_PRE(sender);  // the sender object
            QS_SIG_PRE(e->sig);  // the signal of the event
            QS_OBJ_PRE(this);    // this active object (recipient)
            QS_2U8_PRE(e->poolNum_, e->refCtr_);
            QS_EQC_PRE(nFree);   // # free entries
            QS_EQC_PRE(margin);  // margin requested
        QS_END_PRE()
 
#ifdef Q_UTEST
        if (QS_LOC_CHECK_(m_prio)) {
            QF_CRIT_EXIT();
            QS::onTestPost(sender, this, e, status);
            QF_CRIT_ENTRY();
        }
#endif // def Q_USTEST
 
        QF_CRIT_EXIT();
 
#if (QF_MAX_EPOOL > 0U)
        QF::gc(e); // recycle the event to avoid a leak
#endif // (QF_MAX_EPOOL > 0U)
    }
 
    return status;
}
 
//............................................................................
void QActive::postLIFO(QEvt const * const e) noexcept {
#ifdef Q_UTEST // test?
#if (Q_UTEST != 0) // testing QP-stub?
    if (m_temp.fun == Q_STATE_CAST(0)) { // QActiveDummy?
        static_cast<QActiveDummy *>(this)->QActiveDummy::fakePostLIFO(e);
        return;
    }
#endif // (Q_UTEST != 0)
#endif // def Q_UTEST
 
    QF_CRIT_STAT
    QF_CRIT_ENTRY();
 
    // the posted event must be be valid (which includes not NULL)
    Q_REQUIRE_INCRIT(300, e != nullptr);
 
    QEQueueCtr tmp = m_eQueue.m_nFree; // get volatile into temporary
 
    // The queue must NOT overflow for the LIFO posting policy.
    Q_REQUIRE_INCRIT(310, tmp != 0U);
 
    if (e->poolNum_ != 0U) { // is it a mutable event?
        Q_ASSERT_INCRIT(305, e->refCtr_ < (2U * QF_MAX_ACTIVE));
        QEvt_refCtr_inc_(e); // increment the reference counter
    }
 
    --tmp; // one free entry just used up
 
    m_eQueue.m_nFree = tmp; // update the original
    if (m_eQueue.m_nMin > tmp) {
        m_eQueue.m_nMin = tmp; // update minimum so far
    }
 
    QS_BEGIN_PRE(QS_QF_ACTIVE_POST_LIFO, m_prio)
        QS_TIME_PRE();       // timestamp
        QS_SIG_PRE(e->sig);  // the signal of this event
        QS_OBJ_PRE(this);    // this active object
        QS_2U8_PRE(e->poolNum_, e->refCtr_);
        QS_EQC_PRE(tmp);     // # free entries
        QS_EQC_PRE(m_eQueue.m_nMin); // min # free entries
    QS_END_PRE()
 
#ifdef Q_UTEST
    // callback to examine the posted event under the same conditions
    // as producing the #QS_QF_ACTIVE_POST trace record, which are:
    // the local filter for this AO ('m_prio') is set
    if (QS_LOC_CHECK_(m_prio)) {
        QF_CRIT_EXIT();
 
        QS::onTestPost(nullptr, this, e, true);
 
        QF_CRIT_ENTRY();
    }
#endif // def Q_UTEST
 
    QEvt const * const frontEvt = m_eQueue.m_frontEvt;
    m_eQueue.m_frontEvt = e; // deliver the event directly to the front
 
    if (frontEvt != nullptr) { // was the queue NOT empty?
        tmp = m_eQueue.m_tail; // get volatile into temporary;
        ++tmp;
        if (tmp == m_eQueue.m_end) { // need to wrap the tail?
            tmp = 0U; // wrap around
        }
        m_eQueue.m_tail = tmp;
        m_eQueue.m_ring[tmp] = frontEvt;
    }
    else { // queue was empty
        QACTIVE_EQUEUE_SIGNAL_(this); // signal the event queue
    }
 
    QF_CRIT_EXIT();
}
 
//............................................................................
QEvt const * QActive::get_() noexcept {
    QF_CRIT_STAT
    QF_CRIT_ENTRY();
 
    // wait for event to arrive directly (depends on QP port)
    // NOTE: might use assertion-IDs 400-409
    QACTIVE_EQUEUE_WAIT_(this); // wait for event to arrive directly
 
    // always remove event from the front
    QEvt const * const e = m_eQueue.m_frontEvt;
    QEQueueCtr tmp = m_eQueue.m_nFree; // get volatile into temporary
 
    Q_REQUIRE_INCRIT(410, e != nullptr); // queue must NOT be empty
 
    ++tmp; // one more free event in the queue
 
    m_eQueue.m_nFree = tmp; // update the # free
 
    if (tmp <= m_eQueue.m_end) { // any events in the ring buffer?
 
        QS_BEGIN_PRE(QS_QF_ACTIVE_GET, m_prio)
            QS_TIME_PRE();       // timestamp
            QS_SIG_PRE(e->sig);  // the signal of this event
            QS_OBJ_PRE(this);    // this active object
            QS_2U8_PRE(e->poolNum_, e->refCtr_);
            QS_EQC_PRE(tmp);     // # free entries
        QS_END_PRE()
 
        // remove event from the tail
        tmp = m_eQueue.m_tail; // get volatile into temporary
        QEvt const * const frontEvt = m_eQueue.m_ring[tmp];
 
        Q_ASSERT_INCRIT(430, frontEvt != nullptr);
        m_eQueue.m_frontEvt = frontEvt; // update the original
 
        if (tmp == 0U) { // need to wrap the tail?
            tmp = m_eQueue.m_end;
        }
        --tmp; // advance the tail (counter-clockwise)
 
        m_eQueue.m_tail = tmp; // update the original
    }
    else {
        m_eQueue.m_frontEvt = nullptr; // the queue becomes empty
 
        // all entries in the queue must be free (+1 for fronEvt)
        Q_ASSERT_INCRIT(440, tmp == (m_eQueue.m_end + 1U));
 
        QS_BEGIN_PRE(QS_QF_ACTIVE_GET_LAST, m_prio)
            QS_TIME_PRE();       // timestamp
            QS_SIG_PRE(e->sig);  // the signal of this event
            QS_OBJ_PRE(this);    // this active object
            QS_2U8_PRE(e->poolNum_, e->refCtr_);
        QS_END_PRE()
    }
 
    QF_CRIT_EXIT();
 
    return e;
}
 
//............................................................................
void QActive::postFIFO_(
    QEvt const * const e,
    void const * const sender)
{
    // NOTE: this helper function is called *inside* critical section
#ifndef Q_SPY
    Q_UNUSED_PAR(sender);
#endif
 
    QEQueueCtr tmp = m_eQueue.m_nFree; // get volatile into temporary
    --tmp; // one free entry just used up
 
    m_eQueue.m_nFree = tmp; // update the original
    if (m_eQueue.m_nMin > tmp) {
        m_eQueue.m_nMin = tmp; // update minimum so far
    }
 
    QS_BEGIN_PRE(QS_QF_ACTIVE_POST, m_prio)
        QS_TIME_PRE();        // timestamp
        QS_OBJ_PRE(sender);   // the sender object
        QS_SIG_PRE(e->sig);   // the signal of the event
        QS_OBJ_PRE(this);     // this active object (recipient)
        QS_2U8_PRE(e->poolNum_, e->refCtr_);
        QS_EQC_PRE(tmp);      // # free entries
        QS_EQC_PRE(m_eQueue.m_nMin); // min # free entries
    QS_END_PRE()
 
#ifdef Q_UTEST
    if (QS_LOC_CHECK_(m_prio)) {
        QF_CRIT_EXIT();
        QS::onTestPost(sender, this, e, true); // QUTEst callback
        QF_CRIT_ENTRY();
    }
#endif // def Q_UTEST
 
    if (m_eQueue.m_frontEvt == nullptr) { // is the queue empty?
        m_eQueue.m_frontEvt = e; // deliver event directly
 
#ifdef QXK_HPP_
        if (m_state.act == nullptr) { // eXtended thread?
            QXTHREAD_EQUEUE_SIGNAL_(this); // signal eXtended Thread
        }
        else {
            QACTIVE_EQUEUE_SIGNAL_(this); // signal the Active Object
        }
#else
        QACTIVE_EQUEUE_SIGNAL_(this); // signal the Active Object
#endif // def QXK_HPP_
    }
    else { // queue was not empty, insert event into the ring-buffer
        tmp = m_eQueue.m_head; // get volatile into temporary
        m_eQueue.m_ring[tmp] = e; // insert e into buffer
 
        if (tmp == 0U) { // need to wrap the head?
            tmp = m_eQueue.m_end;
        }
        --tmp; // advance the head (counter-clockwise)
 
        m_eQueue.m_head = tmp; // update the original
    }
}
 
//............................................................................
std::uint_fast16_t QActive::getQueueMin(std::uint_fast8_t const prio) noexcept {
    QF_CRIT_STAT
    QF_CRIT_ENTRY();
    Q_REQUIRE_INCRIT(600, (prio <= QF_MAX_ACTIVE)
                      && (registry_[prio] != nullptr));
    std::uint_fast16_t const min =
         static_cast<std::uint_fast16_t>(registry_[prio]->m_eQueue.m_nMin);
    QF_CRIT_EXIT();
 
    return min;
}
 
//============================================================================
 
QTicker::QTicker(std::uint_fast8_t const tickRate) noexcept
: QActive(nullptr)
{
    // reuse m_head for tick-rate
    m_eQueue.m_head = static_cast<QEQueueCtr>(tickRate);
}
 
//............................................................................
void QTicker::init(
    void const * const e,
    std::uint_fast8_t const qsId)
{
    Q_UNUSED_PAR(e);
    Q_UNUSED_PAR(qsId);
 
    QF_CRIT_STAT
    QF_CRIT_ENTRY();
    m_eQueue.m_tail = 0U;
    QF_CRIT_EXIT();
}
 
//............................................................................
void QTicker::dispatch(
    QEvt const * const e,
    std::uint_fast8_t const qsId)
{
    Q_UNUSED_PAR(e);
    Q_UNUSED_PAR(qsId);
 
    QF_CRIT_STAT
    QF_CRIT_ENTRY();
 
    // get volatile into temporaries
    QEQueueCtr nTicks = m_eQueue.m_tail;
    QEQueueCtr const tickRate = m_eQueue.m_head;
 
    Q_REQUIRE_INCRIT(800, nTicks > 0U);
    m_eQueue.m_tail = 0U; // clear # ticks
    QF_CRIT_EXIT();
 
    for (; nTicks > 0U; --nTicks) {
        QTimeEvt::tick(static_cast<std::uint_fast8_t>(tickRate),
                       this);
    }
}
 
//............................................................................
void QTicker::trig_(void const * const sender) noexcept {
#ifndef Q_SPY
    Q_UNUSED_PAR(sender);
#endif
 
    static QEvt const tickEvt(0U); // immutable event
 
    QF_CRIT_STAT
    QF_CRIT_ENTRY();
 
    QEQueueCtr nTicks = m_eQueue.m_tail; // get volatile into temporary
 
    if (m_eQueue.m_frontEvt == nullptr) {
        Q_REQUIRE_INCRIT(900,
            (m_eQueue.m_nFree == 1U)
            && (nTicks == 0U));
 
        m_eQueue.m_frontEvt = &tickEvt; // deliver event directly
        m_eQueue.m_nFree = 0U;
 
        QACTIVE_EQUEUE_SIGNAL_(this); // signal the event queue
    }
    else {
        Q_REQUIRE_INCRIT(910, (nTicks > 0U) && (nTicks < 0xFFU));
        Q_REQUIRE_INCRIT(920, m_eQueue.m_nFree == 0U);
    }
 
    ++nTicks; // account for one more tick event
 
    m_eQueue.m_tail = nTicks; // update the original
 
    QS_BEGIN_PRE(QS_QF_ACTIVE_POST, m_prio)
        QS_TIME_PRE();      // timestamp
        QS_OBJ_PRE(sender); // the sender object
        QS_SIG_PRE(0U);     // the signal of the event
        QS_OBJ_PRE(this);   // this active object
        QS_2U8_PRE(0U, 0U); // poolNum & refCtr
        QS_EQC_PRE(0U);     // # free entries
        QS_EQC_PRE(0U);     // min # free entries
    QS_END_PRE()
 
    QF_CRIT_EXIT();
}
 
} // namespace QP