osconditionvariable.h

/******************************************************************************
 
    @file    IntrOS: osconditionvariable.h
    @author  Rajmund Szymanski
    @date    17.11.2025
    @brief   This file contains definitions for IntrOS.
 
 ******************************************************************************
 
   Copyright (c) 2018-2022 Rajmund Szymanski. All rights reserved.
 
   Permission is hereby granted, free of charge, to any person obtaining a copy
   of this software and associated documentation files (the "Software"), to
   deal in the Software without restriction, including without limitation the
   rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
   sell copies of the Software, and to permit persons to whom the Software is
   furnished to do so, subject to the following conditions:
 
   The above copyright notice and this permission notice shall be included
   in all copies or substantial portions of the Software.
 
   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
   THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
   IN THE SOFTWARE.
 
 ******************************************************************************/
 
#ifndef __INTROS_CND_H
#define __INTROS_CND_H
 
#include "oskernel.h"
#include "osclock.h"
#include "osmutex.h"

 
/* -------------------------------------------------------------------------- */
 
#define cndOne       ( false ) 
#define cndAll       ( true  ) 

 
typedef struct __cnd cnd_t;
 
struct __cnd
{
    obj_t    obj;   
};
 
typedef struct __cnd cnd_id [];
 
/******************************************************************************
 *
 * Name              : _CND_INIT
 *
 * Description       : create and initialize a condition variable object
 *
 * Parameters        : none
 *
 * Return            : condition variable object
 *
 * Note              : for internal use
 *
 ******************************************************************************/
 
#define               _CND_INIT() { _OBJ_INIT() }

 
#define             OS_CND( cnd ) \
                       cnd_t cnd[] = { _CND_INIT() }

/** static alias of OS_CND() */
#define         static_CND( cnd ) \
                static cnd_t cnd[] = { _CND_INIT() }

 
#ifndef __cplusplus
#define                CND_INIT() \
                      _CND_INIT()
#endif

 
#ifndef __cplusplus
#define                CND_CREATE() \
                     { CND_INIT  () }
/** alias of CND_CREATE() */
#define                CND_NEW \
                       CND_CREATE
#endif
 
#ifdef __cplusplus
extern "C" {
#endif

 
void cnd_init( cnd_t *cnd );

 
void cnd_reset( cnd_t *cnd );

__STATIC_INLINE
void cnd_kill( cnd_t *cnd ) { cnd_reset(cnd); }

 
int cnd_waitFor( cnd_t *cnd, mtx_t *mtx, cnt_t delay );

 
int cnd_waitUntil( cnd_t *cnd, mtx_t *mtx, cnt_t time );

 
__STATIC_INLINE
int cnd_wait( cnd_t *cnd, mtx_t *mtx ) { return cnd_waitFor(cnd, mtx, INFINITE); }

 
void cnd_give( cnd_t *cnd, bool all );

 
__STATIC_INLINE
void cnd_notifyOne( cnd_t *cnd ) { cnd_give(cnd, cndOne); }

 
__STATIC_INLINE
void cnd_notifyAll( cnd_t *cnd ) { cnd_give(cnd, cndAll); }
 
#ifdef __cplusplus
}
#endif
 
/* -------------------------------------------------------------------------- */
 
#if defined(__cplusplus)
namespace intros {

 
struct ConditionVariable : public __cnd
{
    constexpr
    ConditionVariable(): __cnd _CND_INIT() {}
 
    ~ConditionVariable() { assert(__cnd::obj.queue == nullptr); }

    /// move constructor
    ConditionVariable( ConditionVariable&& _src ): __cnd(_src)
    {
        assert(_src.obj.queue == nullptr);
    }
 
    ConditionVariable( const ConditionVariable& ) = delete;
    ConditionVariable& operator=( ConditionVariable&& ) = delete;
    ConditionVariable& operator=( const ConditionVariable& ) = delete;
 
    void reset    ()                               {        cnd_reset    (this); }                              
    void kill     ()                               {        cnd_kill     (this); }                              
    template<typename T>
    int  waitFor  ( mtx_t& _mtx, const T& _delay ) { return cnd_waitFor  (this, &_mtx, Clock::count(_delay)); } 
    template<typename T>
    int  waitUntil( mtx_t& _mtx, const T& _time )  { return cnd_waitUntil(this, &_mtx, Clock::until(_time)); }  
    int  wait     ( mtx_t& _mtx )                  { return cnd_wait     (this, &_mtx); }                       
    void give     ( bool   _all = cndAll )         {        cnd_give     (this,  _all); }                       
    void notifyOne()                               {        cnd_notifyOne(this); }                              
    void notifyAll()                               {        cnd_notifyAll(this); }                              
    template<typename T, typename F>
    int  waitFor  ( mtx_t& _mtx, const T& _delay, F _stopWaiting )
    {
        auto _time = Clock::count(_delay);
        return (_time == INFINITE) ? wait(_mtx, _stopWaiting)
                                   : waitUntil(_mtx, sys_time() + _time, _stopWaiting);
    }
    template<typename T, typename F>
    int  waitUntil( mtx_t& _mtx, const T& _time, F _stopWaiting )
    {
        int result = E_SUCCESS;
        while (!_stopWaiting() && (result = waitUntil(_mtx, _time)) == E_SUCCESS);
        if (result == E_TIMEOUT && _stopWaiting())  // the mutex is held again, the condition may have been satisfied during the timeout
            result = E_SUCCESS;
        return result;
    }
    template<typename F>
    int  wait     ( mtx_t& _mtx, F _stopWaiting )
    {
        int result = E_SUCCESS;
        while (!_stopWaiting() && (result = wait(_mtx)) == E_SUCCESS);
        return result;
    }
};
 
}     //  namespace
#endif//__cplusplus
 
/* -------------------------------------------------------------------------- */

 
#endif//__INTROS_CND_H