qpc/ports/win32/vc/qf_port.h

/*****************************************************************************
* Product: QF/C port to Win32
* Last Updated for Version: 5.0.0
* Date of the Last Update:  Sep 12, 2013
*
*                    Q u a n t u m     L e a P s
*                    ---------------------------
*                    innovating embedded systems
*
* Copyright (C) 2002-2013 Quantum Leaps, LLC. 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 <http://www.gnu.org/licenses/>.
*
* Contact information:
* Quantum Leaps Web sites: http://www.quantum-leaps.com
*                          http://www.state-machine.com
* e-mail:                  info@quantum-leaps.com
*****************************************************************************/
#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

                                      /* Win32 critical section, see NOTE01 */
/* QF_CRIT_STAT_TYPE not defined */
#define QF_CRIT_ENTRY(dummy)        QF_enterCriticalSection_()
#define QF_CRIT_EXIT(dummy)         QF_leaveCriticalSection_()

#include "qep_port.h"                                           /* QEP port */
#include "qequeue.h"                             /* Win32 needs event-queue */
#include "qmpool.h"                              /* Win32 needs 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 */
void QF_onClockTick(void);     /* clock tick callback (provided in the app) */

/*****************************************************************************
* interface used only inside QF, but not in applications
*/
#ifdef qf_pkg_h
                                   /* Win32 OS object object implementation */
    #define QACTIVE_EQUEUE_WAIT_(me_) \
        while ((me_)->eQueue.frontEvt == (QEvt *)0) { \
            QF_CRIT_EXIT_(); \
            (void)WaitForSingleObject((me_)->osObject, (DWORD)INFINITE); \
            QF_CRIT_ENTRY_(); \
        }

    #define QACTIVE_EQUEUE_SIGNAL_(me_) \
        (void)SetEvent((me_)->osObject)

    #define QACTIVE_EQUEUE_ONEMPTY_(me_) ((void)0)

                                         /* native QF event pool operations */
    #define QF_EPOOL_TYPE_            QMPool
    #define QF_EPOOL_INIT_(p_, poolSto_, poolSize_, evtSize_) \
        QMPool_init(&(p_), poolSto_, poolSize_, evtSize_)
    #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 */

#endif

/* NOTES: ********************************************************************
*
* NOTE01:
* 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.
*/

#endif                                                         /* qf_port_h */