Thread.h

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/*********************************************************\
 *  File: Thread.h                                       *
 *
 *  Copyright (C) 2002-2012 The PixelLight Team (http://www.pixellight.org/)
 *
 *  This file is part of PixelLight.
 *
 *  PixelLight is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  PixelLight 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 Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with PixelLight. If not, see <http://www.gnu.org/licenses/>.
\*********************************************************/


#ifndef __PLCORE_THREAD_H__
#define __PLCORE_THREAD_H__
#pragma once


//[-------------------------------------------------------]
//[ Includes                                              ]
//[-------------------------------------------------------]
#include "PLCore/String/String.h"
#include "PLCore/System/ThreadFunction.h"


//[-------------------------------------------------------]
//[ Namespace                                             ]
//[-------------------------------------------------------]
namespace PLCore {


//[-------------------------------------------------------]
//[ Forward declarations                                  ]
//[-------------------------------------------------------]
class ThreadImpl;


//[-------------------------------------------------------]
//[ Data types                                            ]
//[-------------------------------------------------------]
typedef int (*THREADFUNCTION)(void*);   /**< Static thread function */


//[-------------------------------------------------------]
//[ Classes                                               ]
//[-------------------------------------------------------]
/**
*  @brief
*    Thread class
*
*  @note
*    - Implementation of the bridge design pattern, this class is the abstraction
*/
class Thread : public ThreadFunction {


    //[-------------------------------------------------------]
    //[ Friends                                               ]
    //[-------------------------------------------------------]
    friend class System;
    friend class ThreadLinux;


    //[-------------------------------------------------------]
    //[ Public definitions                                    ]
    //[-------------------------------------------------------]
    public:
        /**
        *  @brief
        *    Thread priority class
        */
        enum EPriorityClass {
            IdlePriorityClass,          /**< Idle priority class */
            BelowNormalPriorityClass,   /**< Below normal priority class */
            NormalPriorityClass,        /**< Normal priority class (default) */
            AboveNormalPriorityClass,   /**< Above normal priority class */
            HighPriorityClass,          /**< High priority class */
            RealtimePriorityClass       /**< Realtime priority class (ONLY use this if you REALLY need it!) */
        };

        /**
        *  @brief
        *    Thread priority within the priority class it is in
        */
        enum EPriority {
            IdlePriority,           /**< Idle priority */
            LowestPriority,         /**< Lowest priority */
            BelowNormalPriority,    /**< Below normal priority */
            NormalPriority,         /**< Normal priority (default) */
            AboveNormalPriority,    /**< Above normal priority */
            HighestPriority,        /**< Highest priority */
            TimeCriticalPriority    /**< Time critical priority */
        };


    //[-------------------------------------------------------]
    //[ Public functions                                      ]
    //[-------------------------------------------------------]
    public:
        /**
        *  @brief
        *    Constructor
        */
        PLCORE_API Thread();

        /**
        *  @brief
        *    Constructor
        *
        *  @param[in] pThreadFunction
        *    Pointer to the thread function, can be a null pointer
        */
        PLCORE_API Thread(ThreadFunction *pThreadFunction);

        /**
        *  @brief
        *    Constructor
        *
        *  @param[in] pThreadFunction
        *    Pointer to a static thread function, can be a null pointer
        *  @param[in] pData
        *    Data to be passed to the thread function, can be a null pointer
        */
        PLCORE_API Thread(THREADFUNCTION pThreadFunction, void *pData);

        /**
        *  @brief
        *    Constructor
        *
        *  @param[in] nThreadID
        *    A system specific thread ID, NULL_HANDLE for current thread
        */
        PLCORE_API Thread(handle nThreadID);

        /**
        *  @brief
        *    Destructor
        */
        PLCORE_API virtual ~Thread();

        /**
        *  @brief
        *    Returns the name of the thread
        *
        *  @return
        *    Thread name
        *
        *  @remarks
        *    The thread name is not used internally, it's for user usage only and especially
        *    for debugging purposes quite useful. It's recommended to give threads unique
        *    names. By default, no thread name is set.
        */
        inline String GetName() const;

        /**
        *  @brief
        *    Sets the name of the thread
        *
        *  @param[in] sName
        *    Thread name
        *
        *  @see
        *    - GetName()
        */
        inline void SetName(const String &sName);

        /**
        *  @brief
        *    Returns the unique system ID of the thread
        *
        *  @return
        *    Thread ID
        */
        inline handle GetID() const;

        /**
        *  @brief
        *    Returns whether the thread is active
        *
        *  @return
        *    'true' if the thread is active, else 'false'
        */
        inline bool IsActive() const;

        /**
        *  @brief
        *    Starts the execution of the thread
        *
        *  @return
        *    'true' if the thread could be started
        */
        inline bool Start();

        /**
        *  @brief
        *    Stops the execution of the thread
        *
        *  @return
        *    'true' if the thread could be stopped
        *
        *  @remarks
        *    Terminates the thread ungracefully (does not allow proper thread clean up!). Instead of
        *    using this function you should signal the thread and wait until it has quit by itself.
        *    The internal platform implementation may or may not accept this violent act. For example,
        *    Androids Bionic doesn't support it and a call of this method will have no effect at all.
        */
        inline bool Terminate();

        /**
        *  @brief
        *    Waits until the thread has been stopped
        *
        *  @return
        *    'true' if the thread has been stopped
        *
        *  @note
        *    - It's recommended to use the join version with a timeout instead of this function to
        *      ensure that the thread is stopped within a defined time (no deadlock's)
        */
        inline bool Join();

        /**
        *  @brief
        *    Waits until the thread has been stopped
        *
        *  @param[in] nTimeout
        *    Time in milliseconds to wait
        *
        *  @return
        *    'true' if the thread has been stopped
        */
        inline bool Join(uint64 nTimeout);

        /**
        *  @brief
        *    Returns the priority class the thread is in
        *
        *  @return
        *    The priority class the thread is in
        *
        *  @remarks
        *    The thread priority settings are only 'hints' for the OS how to deal with the thread. They
        *    are no 'facts' and may differ from OS to OS.
        */
        inline EPriorityClass GetPriorityClass() const;

        /**
        *  @brief
        *    Sets the priority class the thread is in
        *
        *  @param[in] nPriorityClass
        *    New priority class the thread is in
        *
        *  @return
        *    'true' if all went fine, else 'false'
        *
        *  @see
        *    - GetPriorityClass()
        */
        inline bool SetPriorityClass(EPriorityClass nPriorityClass = NormalPriorityClass);

        /**
        *  @brief
        *    Returns the thread priority within the priority class it is in
        *
        *  @return
        *    The thread priority within the priority class it is in
        *
        *  @see
        *    - GetPriorityClass()
        */
        inline EPriority GetPriority() const;

        /**
        *  @brief
        *    Sets the thread priority within the priority class it is in
        *
        *  @param[in] nPriority
        *    New thread priority within the priority class it is in
        *
        *  @return
        *    'true' if all went fine, else 'false'
        *
        *  @see
        *    - GetPriorityClass()
        */
        inline bool SetPriority(EPriority nPriority = NormalPriority);


    //[-------------------------------------------------------]
    //[ Public virtual ThreadFunction functions               ]
    //[-------------------------------------------------------]
    public:
        PLCORE_API virtual int Run() override;


    //[-------------------------------------------------------]
    //[ Private functions                                     ]
    //[-------------------------------------------------------]
    private:
        /**
        *  @brief
        *    Copy constructor
        *
        *  @param[in] cSource
        *    Source to copy from
        */
        Thread(const Thread &cSource);

        /**
        *  @brief
        *    Copy operator
        *
        *  @param[in] cSource
        *    Source to copy from
        *
        *  @return
        *    Reference to this instance
        */
        Thread &operator =(const Thread &cSource);


    //[-------------------------------------------------------]
    //[ Private data                                          ]
    //[-------------------------------------------------------]
    private:
        ThreadImpl     *m_pThreadImpl;      /**< Pointer to the system specific implementation (assumed to be never a null pointer!) */
        ThreadFunction *m_pThreadFunction;  /**< Pointer to a thread function to execute, can be a null pointer */
        THREADFUNCTION  m_pStaticFunction;  /**< Pointer to a static function to execute, can be a null pointer */
        void           *m_pStaticData;      /**< Additional data to pass to the static function, can be a null pointer */
        String          m_sName;            /**< Thread name */


};


//[-------------------------------------------------------]
//[ Namespace                                             ]
//[-------------------------------------------------------]
} // PLCore


//[-------------------------------------------------------]
//[ Implementation                                        ]
//[-------------------------------------------------------]
#include "PLCore/System/Thread.inl"


#endif // __PLCORE_THREAD_H__