qpcpp/ports/posix-qv/qf_port.hpp

//============================================================================
// Copyright (C) 2005 Quantum Leaps, LLC <state-machine.com>.
//
// 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 version 3 (or any later version), or alternatively,
// under the terms of one of the closed source Quantum Leaps commercial
// licenses.
//
// The terms of the open source GNU General Public License version 3
// can be found at: <www.gnu.org/licenses/gpl-3.0>
//
// The terms of the closed source Quantum Leaps commercial licenses
// can be found at: <www.state-machine.com/licensing>
//
// Redistributions in source code must retain this top-level comment block.
// Plagiarizing this software to sidestep the license obligations is illegal.
//
// Contact information:
// <www.state-machine.com/licensing>
// <info@state-machine.com>
//============================================================================
//! @date Last updated on: 2022-06-30
//! @version Last updated for: @ref qpcpp_7_0_1
//!
//! @file
//! @brief QF/C++ port to POSIX API with cooperative QV scheduler (posix-qv)

#ifndef QF_PORT_HPP
#define QF_PORT_HPP

// event queue and thread types
#define QF_EQUEUE_TYPE       QEQueue
// QF_OS_OBJECT_TYPE not used
// QF_THREAD_TYPE    not used

// The maximum number of active objects in the application
#define QF_MAX_ACTIVE        64U

// The number of system clock tick rates
#define QF_MAX_TICK_RATE     2U

// Activate the QF QActive::stop() API
#define QF_ACTIVE_STOP       1

// various QF object sizes configuration for this port
#define QF_EVENT_SIZ_SIZE    4U
#define QF_EQUEUE_CTR_SIZE   4U
#define QF_MPOOL_SIZ_SIZE    4U
#define QF_MPOOL_CTR_SIZE    4U
#define QF_TIMEEVT_CTR_SIZE  4U

// QF critical section, see NOTE1
// QF_CRIT_STAT_TYPE not defined
#define QF_CRIT_ENTRY(dummy) QP::QF::enterCriticalSection_()
#define QF_CRIT_EXIT(dummy)  QP::QF::leaveCriticalSection_()

// QF_LOG2 not defined -- use the internal LOG2() implementation

#include "qep_port.hpp"  // QEP port
#include "qequeue.hpp"   // POSIX-QV needs event-queue
#include "qmpool.hpp"    // POSIX-QV needs memory-pool
#include "qf.hpp"        // QF platform-independent public interface

namespace QP {
namespace QF {

void enterCriticalSection_(void);
void leaveCriticalSection_(void);

// set clock tick rate and p-thread priority
// (NOTE: ticksPerSec==0 disables the "ticker thread"
void setTickRate(uint32_t ticksPerSec, int_t tickPrio);

// clock tick callback (NOTE not called when "ticker thread" is not running)
void onClockTick(void);

// abstractions for console access...
void consoleSetup(void);
void consoleCleanup(void);
int consoleGetKey(void);
int consoleWaitForKey(void);

} // namespace QF
} // namespace QP

//============================================================================
// interface used only inside QF, but not in applications

#ifdef QP_IMPL

    // scheduler locking (not needed in single-thread port)
    #define QF_SCHED_STAT_
    #define QF_SCHED_LOCK_(dummy) (static_cast<void>(0))
    #define QF_SCHED_UNLOCK_()    (static_cast<void>(0))

    // native event queue operations...
    #define QACTIVE_EQUEUE_WAIT_(me_) \
        Q_ASSERT((me_)->m_eQueue.m_frontEvt != nullptr)

    #define QACTIVE_EQUEUE_SIGNAL_(me_) \
        QF::readySet_.insert((me_)->m_prio); \
        pthread_cond_signal(&QV_condVar_)

    // native QF event pool operations
    #define QF_EPOOL_TYPE_  QMPool
    #define QF_EPOOL_INIT_(p_, poolSto_, poolSize_, evtSize_) \
        (p_).init((poolSto_), (poolSize_), (evtSize_))
    #define QF_EPOOL_EVENT_SIZE_(p_)  ((p_).getBlockSize())
    #define QF_EPOOL_GET_(p_, e_, m_, qs_id_) \
        ((e_) = static_cast<QEvt *>((p_).get((m_), (qs_id_))))
    #define QF_EPOOL_PUT_(p_, e_, qs_id_)  ((p_).put((e_), (qs_id_)))

    #include <pthread.h>   // POSIX-thread API

    namespace QP {
        extern pthread_cond_t QV_condVar_; // Cond.var. to signal events
    } // namespace QP

#endif // QP_IMPL

// NOTES: ====================================================================
//
// NOTE1:
// QF, like all real-time frameworks, needs to execute certain sections of
// code exclusively, meaning that only one thread can execute the code at
// the time. Such sections of code are called "critical sections"
//
// This port uses a pair of functions QF::enterCriticalSection_() /
// QF::leaveCriticalSection_() to enter/leave the cirtical section,
// respectively.
//
// These functions are implemented in the qf_port.cpp module, where they
// manipulate the file-scope POSIX mutex object l_pThreadMutex_
// to protect all critical sections. Using the single mutex for all crtical
// section guarantees that only one thread at a time can execute inside a
// critical section. This prevents race conditions and data corruption.
//
// Please note, however, that the POSIX mutex implementation behaves
// differently than interrupt disabling. A common POSIX mutex ensures
// that only one thread at a time can execute a critical section, but it
// does not guarantee that a context switch cannot occur within the
// critical section. In fact, such context switches probably will happen,
// but they should not cause concurrency hazards because the critical
// section eliminates all race conditionis.
//
// Unlinke simply disabling and enabling interrupts, the mutex approach is
// also subject to priority inversions. However, the p-thread mutex
// implementation, such as POSIX threads, should support the priority-
// inheritance protocol.
//

#endif // QF_PORT_HPP