qpcpp/ports/win32/qf_port.hpp

/// @file
/// @brief QF/C++ port to Win32 API (multi-threaded)
/// @ingroup ports
/// @cond
///***************************************************************************
/// Last updated for version 6.8.2
/// Last updated on  2020-06-23
///
///                    Q u a n t u m  L e a P s
///                    ------------------------
///                    Modern Embedded Software
///
/// Copyright (C) 2005-2020 Quantum Leaps. All rights reserved.
///
/// This program is open source software: you can redistribute it and/or
/// modify it under the terms of the GNU General Public License as published
/// by the Free Software Foundation, either version 3 of the License, or
/// (at your option) any later version.
///
/// Alternatively, this program may be distributed and modified under the
/// terms of Quantum Leaps commercial licenses, which expressly supersede
/// the GNU General Public License and are specifically designed for
/// licensees interested in retaining the proprietary status of their code.
///
/// This program is distributed in the hope that it will be useful,
/// but WITHOUT ANY WARRANTY; without even the implied warranty of
/// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
/// GNU General Public License for more details.
///
/// You should have received a copy of the GNU General Public License
/// along with this program. If not, see <www.gnu.org/licenses>.
///
/// Contact information:
/// <www.state-machine.com/licensing>
/// <info@state-machine.com>
///***************************************************************************
/// @endcond
///
#ifndef QF_PORT_HPP
#define QF_PORT_HPP

// Win32 event queue and thread types
#define QF_EQUEUE_TYPE       QEQueue
#define QF_OS_OBJECT_TYPE    void*
#define QF_THREAD_TYPE       void*

// 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

// Win32 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"   // Win32 needs event-queue
#include "qmpool.hpp"    // Win32 needs memory-pool
#include "qpset.hpp"     // Win32 needs priority-set
#include "qf.hpp"        // QF platform-independent public interface

namespace QP {

void QF_enterCriticalSection_(void);
void QF_leaveCriticalSection_(void);

// set Win32 thread priority for an active object;
// see: Microsoft documentation for SetThreadPriority()
// NOTE: must be called *after* QActive::START()
//
void QF_setWin32Prio(QActive *act, int_t win32Prio);

// set clock tick rate and priority
void QF_setTickRate(uint32_t ticksPerSec, int_t tickPrio);

// clock tick callback (provided in the app)
void QF_onClockTick(void);

// abstractions for console access...
void QF_consoleSetup(void);
void QF_consoleCleanup(void);
int QF_consoleGetKey(void);
int QF_consoleWaitForKey(void);

} // namespace QP


// special adaptations for QWIN GUI applications
#ifdef QWIN_GUI
    // replace main() with main_gui() as the entry point to a GUI app.
    #define main() main_gui()
    int_t main_gui(); // prototype of the GUI application entry point
#endif

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

#ifdef QP_IMPL

    // Win32-specific scheduler locking, see NOTE2
    #define QF_SCHED_STAT_
    #define QF_SCHED_LOCK_(dummy) QF_enterCriticalSection_()
    #define QF_SCHED_UNLOCK_()    QF_leaveCriticalSection_()

    // Win32-specific event queue customization
    #define QACTIVE_EQUEUE_WAIT_(me_) \
        while ((me_)->m_eQueue.m_frontEvt == nullptr) { \
            QF_CRIT_EXIT_(); \
            (void)WaitForSingleObject((me_)->m_osObject, (DWORD)INFINITE); \
            QF_CRIT_ENTRY_(); \
        }

    #define QACTIVE_EQUEUE_SIGNAL_(me_) \
        Q_ASSERT_ID(410, QF::active_[(me_)->m_prio] != nullptr); \
        (void)SetEvent((me_)->m_osObject)

    // Win32-specific 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_) \
        ((e_) = static_cast<QEvt *>((p_).get((m_))))
    #define QF_EPOOL_PUT_(p_, e_)     ((p_).put(e_))

    // Minimum required Windows version is Windows-XP or newer (0x0501)
    #ifdef WINVER
    #undef WINVER
    #endif
    #ifdef _WIN32_WINNT
    #undef _WIN32_WINNT
    #endif

    #define WINVER _WIN32_WINNT_WINXP
    #define _WIN32_WINNT _WIN32_WINNT_WINXP

    #define WIN32_LEAN_AND_MEAN
    #include <windows.h> // Win32 API

#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.c module, where they
// manipulate the file-scope Win32 critical section object l_win32CritSect
// to protect all critical sections. Using the single critical section
// object 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 Win32 critical section implementation
// behaves differently than interrupt disabling. A common Win32 critical
// section 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 critical section
// approach is also subject to priority inversions. Various versions of
// Windows handle priority inversions differently, but it seems that most of
// them recognize priority inversions and dynamically adjust the priorities of
// threads to prevent it. Please refer to the MSN articles for more
// information.
//
// NOTE2:
// Scheduler locking (used inside QF_publish_()) is implemented in this
// port with the main critical section. This means that event multicasting
// will appear atomic, in the sense that no thread will be able to post
// events during multicasting.
//

#endif // QF_PORT_HPP