osmutex.h

/******************************************************************************
 
    @file    IntrOS: osmutex.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_MTX_H
#define __INTROS_MTX_H
 
#include "oskernel.h"
#include "osclock.h"


 
struct __mtx
{
    obj_t    obj;   
 
    tsk_t  * owner; 
    mtx_t  * list;  
};
 
typedef struct __mtx mtx_id [];
 
/******************************************************************************
 *
 * Name              : _MTX_INIT
 *
 * Description       : create and initialize a mutex object
 *
 * Parameters        : none
 *
 * Return            : mutex object
 *
 * Note              : for internal use
 *
 ******************************************************************************/
 
#define               _MTX_INIT() { _OBJ_INIT(), NULL, NULL }

 
#define             OS_MTX( mtx ) \
                       mtx_t mtx[] = { _MTX_INIT() }

/** static alias of OS_MTX() */
#define         static_MTX( mtx ) \
                static mtx_t mtx[] = { _MTX_INIT() }

 
#ifndef __cplusplus
#define                MTX_INIT() \
                      _MTX_INIT()
#endif

 
#ifndef __cplusplus
#define                MTX_CREATE() \
                     { MTX_INIT  () }
/** alias of MTX_CREATE() */
#define                MTX_NEW \
                       MTX_CREATE
#endif
 
#ifdef __cplusplus
extern "C" {
#endif

 
void mtx_init( mtx_t *mtx );

 
void mtx_reset( mtx_t *mtx );

__STATIC_INLINE
void mtx_kill( mtx_t *mtx ) { mtx_reset(mtx); }

 
int mtx_take( mtx_t *mtx );

__STATIC_INLINE
int mtx_tryLock( mtx_t *mtx ) { return mtx_take(mtx); }

 
int mtx_waitFor( mtx_t *mtx, cnt_t delay );

 
int mtx_waitUntil( mtx_t *mtx, cnt_t time );

 
__STATIC_INLINE
int mtx_wait( mtx_t *mtx ) { return mtx_waitFor(mtx, INFINITE); }

__STATIC_INLINE
int mtx_lock( mtx_t *mtx ) { return mtx_wait(mtx); }

 
int mtx_give( mtx_t *mtx );

__STATIC_INLINE
int mtx_unlock( mtx_t *mtx ) { return mtx_give(mtx); }
 
#ifdef __cplusplus
}
#endif
 
/* -------------------------------------------------------------------------- */
 
#if defined(__cplusplus)
namespace intros {

 
struct Mutex : public __mtx
{
    constexpr
    Mutex(): __mtx _MTX_INIT() {}
 
    ~Mutex() { assert(__mtx::owner == nullptr); }

    /// move constructor
    Mutex( Mutex&& _src ): __mtx(_src)
    {
        assert(_src.owner == nullptr && _src.obj.queue == nullptr);
    }
 
    Mutex( const Mutex& ) = delete;
    Mutex& operator=( Mutex&& ) = delete;
    Mutex& operator=( const Mutex& ) = delete;
 
    void     reset    ()                  {        mtx_reset    (this); }                       
    void     kill     ()                  {        mtx_kill     (this); }                       
    int      take     ()                  { return mtx_take     (this); }                       
    int      tryLock  ()                  { return mtx_tryLock  (this); }                       
    template<typename T>
    int      waitFor  ( const T& _delay ) { return mtx_waitFor  (this, Clock::count(_delay)); } 
    template<typename T>
    int      waitUntil( const T& _time )  { return mtx_waitUntil(this, Clock::until(_time)); }  
    int      wait     ()                  { return mtx_wait     (this); }                       
    int      lock     ()                  { return mtx_lock     (this); }                       
    int      give     ()                  { return mtx_give     (this); }                       
    int      unlock   ()                  { return mtx_unlock   (this); }                       
};

 
struct LockGuard
{
    explicit
    LockGuard( Mutex& _mtx ): mtx_(&_mtx)
    {
        int result = mtx_->lock();
        assert(result == E_SUCCESS || result == E_STOPPED);
        if (result != E_SUCCESS)
            mtx_ = nullptr; // nothing to release
    }
 
    ~LockGuard()
    {
        if (mtx_ == nullptr)
            return;
 
        int result = mtx_->unlock();
        assert(result == E_SUCCESS);
        (void) result;
    }

    /// move constructor
    LockGuard( LockGuard&& _src ): mtx_(_src.mtx_)
    {
        _src.mtx_ = nullptr;
    }

    bool ownsLock() const { return mtx_ != nullptr; }
 
    explicit
    operator bool() const { return ownsLock(); } 
 
    LockGuard( const LockGuard& ) = delete;
    LockGuard& operator=( LockGuard&& ) = delete;
    LockGuard& operator=( const LockGuard& ) = delete;
 
    private:
    Mutex *mtx_;
};

 
struct UniqueLock
{
    explicit
    UniqueLock( Mutex& _mtx ): mtx_(&_mtx), locked_(false)
    {
        lock();
    }

    template<typename T>
    UniqueLock( Mutex& _mtx, const T& _delay ): mtx_(&_mtx), locked_(false)
    {
        waitFor(_delay);
    }

    /// move constructor
    UniqueLock( UniqueLock&& _src ): mtx_(_src.mtx_), locked_(_src.locked_)
    {
        _src.mtx_ = nullptr;
        _src.locked_ = false;
    }
 
    ~UniqueLock()
    {
        unlock();
    }

    UniqueLock() = default;
    UniqueLock( const UniqueLock& ) = delete;
    UniqueLock& operator=( const UniqueLock& ) = delete;

    /// unlock the held mutex and take over the mutex of _src
    UniqueLock& operator=( UniqueLock&& _src )
    {
        unlock();
 
        mtx_ = _src.mtx_;
        locked_ = _src.locked_;
 
        _src.mtx_ = nullptr;
        _src.locked_ = false;
 
        return *this;
    }

    /// try to lock the mutex, don't wait; true: the mutex is locked
    bool tryLock()
    {
        if (mtx_ == nullptr || locked_)
            return false;
 
        int result = mtx_->tryLock();
        assert(result == E_SUCCESS || result == E_TIMEOUT);
        locked_ = result == E_SUCCESS;
        return locked_;
    }

    template<typename T>
    bool waitFor( const T& _delay )
    {
        if (mtx_ == nullptr || locked_)
            return false;
 
        int result = mtx_->waitFor(_delay);
        assert(result == E_SUCCESS || result == E_TIMEOUT || result == E_STOPPED);
        locked_ = result == E_SUCCESS;
        return locked_;
    }

    template<typename T>
    bool waitUntil( const T& _time )
    {
        if (mtx_ == nullptr || locked_)
            return false;
 
        int result = mtx_->waitUntil(_time);
        assert(result == E_SUCCESS || result == E_TIMEOUT || result == E_STOPPED);
        locked_ = result == E_SUCCESS;
        return locked_;
    }

    /// lock the mutex, wait indefinitely; true: the mutex is locked
    bool lock()
    {
        if (mtx_ == nullptr || locked_)
            return false;
 
        int result = mtx_->lock();
        assert(result == E_SUCCESS || result == E_STOPPED);
        locked_ = result == E_SUCCESS;
        return locked_;
    }

    /// unlock the mutex; true: the mutex was unlocked
    bool unlock()
    {
        if (mtx_ == nullptr || !locked_)
            return false;
 
        int result = mtx_->unlock();
        assert(result == E_SUCCESS);
        locked_ = false;
        return result == E_SUCCESS;
    }

    /// true: the mutex is locked by the object
    bool ownsLock() const
    {
        return locked_;
    }

    explicit
    operator bool() const
    {
        return ownsLock();
    }

    /// release the mutex without unlocking it, return the mutex
    Mutex* release()
    {
        Mutex* result = mtx_;
 
        mtx_ = nullptr;
        locked_ = false;
 
        return result;
    }

    /// associated mutex
    Mutex* mutex() const
    {
        return mtx_;
    }
 
    private:
    Mutex *mtx_ = nullptr;
    bool locked_ = false;
};
 
}     //  namespace
#endif//__cplusplus
 
/* -------------------------------------------------------------------------- */

 
#endif//__INTROS_MTX_H