# Source: tothread.h

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    //***************************************************************************
    /*
     * TOra - An Oracle Toolkit for DBA's and developers
     * Copyright (C) 2000-2001,2001 Underscore AB
     *
     * This program is free 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;  only version 2 of
     * the License is valid for this program.
     *
     * 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, write to the Free Software
     * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
     *
     *      As a special exception, you have permission to link this program
     *      with the Oracle Client libraries and distribute executables, as long
     *      as you follow the requirements of the GNU GPL in regard to all of the
     *      software in the executable aside from Oracle client libraries.
     *
     *      Specifically you are not permitted to link this program with the
     *      Qt/UNIX, Qt/Windows or Qt Non Commercial products of TrollTech.
     *      And you are not permitted to distribute binaries compiled against
     *      these libraries without written consent from Underscore AB. Observe
     *      that this does not disallow linking to the Qt Free Edition.
     *
     * All trademarks belong to their respective owners.
     *
     ****************************************************************************/

    #ifndef __TOTHREAD_H
    #define __TOTHREAD_H

    /** This is an abstract class that defines something that is to be performed by a
     * thread.
     */
    class toTask {
    public:
      virtual ~toTask() { }
      /** This member is called when the class is started.
       */
      virtual void run(void) = 0;
    };

    #include <list>

    #ifdef WIN32
    #include <qthread.h>

    class toSemaphore {
    private:
      QMutex Mutex;
      QWaitCondition Condition;
      int Value;
    public:
      toSemaphore()
        : Condition()
      { Value=0; }
      toSemaphore(const toSemaphore &);
      toSemaphore(int val)
        : Condition()
      { Value=val; }

      void up();
      void down();
      int getValue();
    };

    class toLock {
    private:
      QMutex Mutex;
    public:
      toLock(void)
        : Mutex(false)
      { }
      toLock(const toLock &);

      void lock(void)
      { Mutex.lock(); }
      void unlock(void)
      { Mutex.unlock(); }
    };

    class toThread {
    private:
      /** Not part of the API.
       */

      class taskRunner : public QThread {
      public:
        toSemaphore StartSemaphore;
        toTask *Task;
        taskRunner(toTask *);
        virtual void run(void);
        friend class toThread;
      } Thread;
      static std::list<toThread *> *Threads;
      static toLock *Lock;
      static int LastID;
      static __declspec( thread ) int ThreadID;
      static int MainThread;

      toThread(const toThread &);
    public:
      toThread(toTask *);
      ~toThread();

      void start(void);
      void startAsync(void);
      static void msleep(int msec);
      static bool mainThread(void);
      friend class taskRunner;
    };

    #else
    #include <semaphore.h>
    #include <pthread.h>
    #include <signal.h>
    #include <time.h>

    /** Encapsulation of pthread semaphores. A semaphore can be raise to any value
     * but will wait till raised above zero when lowered below 0. Can also be implemented
     * without pthreads using Qt multithreaded primitives. Observe that these function
     * different than Qt semaphores.
     */

    class toSemaphore {
    private:
      /** Actual semaphore.
       */
      sem_t Semaphore;
      /** Initialise semaphore.
       * @param val Value to init semaphore to.
       */
      void init(int val);

      toSemaphore(const toSemaphore &);
    public:
      /** Create semaphore
       */
      toSemaphore();
      /** Create semaphore
       * @param val Value of new semaphore.
       */
      toSemaphore(int val);
      ~toSemaphore();

      /** Increase semaphore value by 1.
       */
      void up();
      /** Decrease semaphore value by 1, wait for it to never go below 0.
       */
      void down();
      /** Get current semaphore value.
       */
      int getValue();
    };

    /** A wrapper around the pthread mutexfunctions. A lock can only be locked
     *  by one thread at a time and is the basis of most thread synchronisation.
     */

    class toLock {
    private:
      /** Actual pthread mutex of class.
       */
      pthread_mutex_t Mutex;
      toLock(const toLock &);
    public:
      /** Create lock
       */
      toLock(void);
      ~toLock();

      /** Lock this lock.
       */
      void lock(void);
      /** Unlock this lock.
       */
      void unlock(void);
    };

    /** Used to create new threads of execution. When a thread exits it will delete the
     * thread and task objects so the calling thread must never delete a started thread.
     */

    class toThread {
    private:
      static toThread *DeleteThread;
      static toLock *Lock;
     /** PThread identifier.
       */
      pthread_t		Thread;
      /** Thread attributes.
       */
      pthread_attr_t	ThreadAttr;
      /** Task to run in new thread.
       */
      toTask		*Task;
      /** Semaphore that is raised when new thread has started running.
       */
      toSemaphore		StartSemaphore;
      /** Initialise thread attributes.
       */
      void			initAttr(void);
      /** Called when thread is started to execute task. Pointer to @ref toThread
       * is passed as parameter.
       */
      friend void		*toThreadStartWrapper(void*);
      /** Main thread id
       */
      static pthread_t MainThread;

      toThread(const toThread &);
    public:
      /** Create thread.
       * @param task Task to run.
       */
      toThread(toTask *task);
      ~toThread();

      /** Start thread and wait for other thread to start running.
       */
      void start(void);
      /** Start thread and continue executing this thread until normal scheduling
       * handles over execution to child thread.
       */
      void startAsync(void);
      /** Sleep in milliseconds.
       */
      static void msleep(int msec);
      /** Returns true if this is the main thread.
       */
      static bool mainThread(void);
    };

    #endif

    /** This is a convenience class that holds a lock for the duration of the scope
     * of the object. It is very convenient to use if exceptions can be thrown, simply
     * declare an auto @ref toLocker to hold the lock. If any exception is thrown the
     * locker will be deallocated and the lock released.
     */

    class toLocker {
    private:
      /** Lock held.
       */
      toLock &Lock;
      toLocker(const toLocker &);
    public:
      /** Create locker.
       * @param lock Lock to hold.
       */
      toLocker(toLock &lock)
        : Lock(lock)
      { Lock.lock(); }
      ~toLocker()
      { Lock.unlock(); }
    };

    #endif