/**
* @file
* @brief QF/C port to Win32 with cooperative QV kernel (win32-qv)
* @cond
******************************************************************************
* Last Updated for Version: 5.4.0
* Date of the Last Update:  2015-04-08
*
*                    Q u a n t u m     L e a P s
*                    ---------------------------
*                    innovating embedded systems
*
* Copyright (C) Quantum Leaps, LLC. state-machine.com.
*
* 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 <http://www.gnu.org/licenses/>.
*
* Contact information:
* Web:   www.state-machine.com
* Email: info@state-machine.com
******************************************************************************
* @endcond
*/
#ifndef qf_port_h
#define qf_port_h

/* 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        63

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

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

/* QF interrupt disable/enable, see NOTE1 */
#define QF_INT_DISABLE()     QF_enterCriticalSection_()
#define QF_INT_ENABLE()      QF_leaveCriticalSection_()

/* Win32 critical section */
/* QF_CRIT_STAT_TYPE not defined */
#define QF_CRIT_ENTRY(dummy) QF_INT_DISABLE()
#define QF_CRIT_EXIT(dummy)  QF_INT_ENABLE()

#include "qep_port.h"  /* QEP port */
#include "qequeue.h"   /* Win32-QV needs the native event-queue */
#include "qmpool.h"    /* Win32-QV needs the native memory-pool */
#include "qf.h"        /* QF platform-independent public interface */

void QF_enterCriticalSection_(void);
void QF_leaveCriticalSection_(void);
void QF_setTickRate(uint32_t ticksPerSec); /* set clock tick rate */

/* application-level clock tick callback */
void QF_onClockTick(void);

/****************************************************************************/
/* interface used only inside QF implementation, but not in applications */
#ifdef QP_IMPL

    /* Win32 OS object object implementation */
    #define QACTIVE_EQUEUE_WAIT_(me_) \
        Q_ASSERT_ID(0, (me_)->eQueue.frontEvt != (QEvt *)0)

    #define QACTIVE_EQUEUE_SIGNAL_(me_) \
        QPSet64_insert(&QV_readySet_, (me_)->prio); \
            (void)SetEvent(QV_win32Event_)

    #define QACTIVE_EQUEUE_ONEMPTY_(me_) \
        QPSet64_remove(&QV_readySet_, (me_)->prio)

    /* native QF event pool operations */
    #define QF_EPOOL_TYPE_  QMPool
    #define QF_EPOOL_INIT_(p_, poolSto_, poolSize_, evtSize_) do { \
        uint_fast32_t fudgedSize = (poolSize_) * QF_WIN32_FUDGE_FACTOR; \
        void *fudgedSto = malloc(fudgedSize); \
        Q_ASSERT_ID(210, fudgedSto != (void *)0); \
        (void)(poolSto_); \
        QMPool_init(&(p_), fudgedSto, fudgedSize, evtSize_); \
    } while (0)

    #define QF_EPOOL_EVENT_SIZE_(p_)  ((p_).blockSize)
    #define QF_EPOOL_GET_(p_, e_, m_) ((e_) = (QEvt *)QMPool_get(&(p_), (m_)))
    #define QF_EPOOL_PUT_(p_, e_)     (QMPool_put(&(p_), e_))

    #define WIN32_LEAN_AND_MEAN
    #include <windows.h> /* Win32 API */
    #include <stdlib.h>  /* for malloc() */
    #include "qpset.h"   /* Win32-QV needs the native QP priority set */

    extern QPSet64 QV_readySet_;   /* QV-ready set of active objects */
    extern HANDLE  QV_win32Event_; /* Win32 event to signal events */

    /* Windows "fudge factor" for oversizing the resources, see NOTE2 */
    #define QF_WIN32_FUDGE_FACTOR  100U

#endif /* QP_IMPL */

/* NOTES: ==================================================================*/
/*
* NOTE1:
* QF, like all real-time frameworks, needs to execute certain sections of
* code indivisibly to avoid data corruption. The most straightforward way of
* protecting such critical sections of code is disabling and enabling
* interrupts, which Win32 does not allow.
*
* This QF port uses therefore a single package-scope Win32 critical section
* object QF_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 locking. 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:
* Windows is not a deterministic real-time system, which means that the
* system can occasionally and unexpectedly "choke and freeze" for a number
* of seconds. The designers of Windows have dealt with these sort of issues
* by massively oversizing the resources available to the applications. For
* example, the default Windows GUI message queues size is 10,000 entries,
* which can dynamically grow to an even larger number. Also the stacks of
* Win32 threads can dynamically grow to several megabytes.
*
* In contrast, the event queues, event pools, and stack size inside the
* real-time embedded (RTE) systems can be (and must be) much smaller,
* because you typically can put an upper bound on the real-time behavior
* and the resulting delays.
*
* To be able to run the unmodified applications designed originally for
* RTE systems on Windows, and to reduce the odds of resource shortages in
* this case, the generous QF_WIN32_FUDGE_FACTOR is used to oversize the
* event queues and event pools.
*/

#endif /* qf_port_h */