qpcpp/ports/win32-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 Win32 API (single-threaded, like the QV kernel)

#ifndef QF_PORT_HPP
#define QF_PORT_HPP

// QF 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"   // Win32-QV needs event-queue
#include "qmpool.hpp"    // Win32-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 (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

// 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-QV specific scheduler locking, see NOTE2
    #define QF_SCHED_STAT_
    #define QF_SCHED_LOCK_(dummy) QF::enterCriticalSection_()
    #define QF_SCHED_UNLOCK_()    QF::leaveCriticalSection_()

    // 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); \
        (void)SetEvent(QV_win32Event_)

    // 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_)))

    // 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

    namespace QP {
        extern HANDLE QV_win32Event_; // Win32 event 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.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 conditions.
//
// 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 not needed in the single-
// threaded Win32-QV port, because event multicasting is already atomic.
//

#endif // QF_PORT_HPP