sync.h

一个不错的fastdb使用例子

//-< SYNC.H >--------------------------------------------------------*--------*
// FastDB                    Version 1.0         (c) 1999  GARRET    *     ?  *
// (Main Memory Database Management System)                          *   /\|  *
//                                                                   *  /  \  *
//                          Created:     20-Nov-98    K.A. Knizhnik  * / [] \ *
//                          Last update: 20-Dec-98    K.A. Knizhnik  * GARRET *
//-------------------------------------------------------------------*--------*
// Intertask synchonization primitives
//-------------------------------------------------------------------*--------*

#ifndef __SYNC_H__
#define __SYNC_H__

class FASTDB_DLL_ENTRY dbSystem
{

public:
  static unsigned getCurrentTimeMsec();
};

#ifdef _WIN32
#include "sync_w32.h"
#else // Unix
#include "sync_unix.h"
#endif

// Common decls for all platforms

class FASTDB_DLL_ENTRY dbCriticalSection
{

private:
  dbMutex& mutex;

public:
  dbCriticalSection(dbMutex& guard) : mutex(guard)
  {
    mutex.lock();
  }

  ~dbCriticalSection()
  {
    mutex.unlock();
  }
};

#define SMALL_BUF_SIZE 512

class FASTDB_DLL_ENTRY dbSmallBuffer
{

protected:
  char   smallBuf[SMALL_BUF_SIZE];
  char*  buf;
  size_t used;

public:
  dbSmallBuffer(size_t size)
  {
    if (size > SMALL_BUF_SIZE)
    {
      buf = new char[size];
    }
    else
    {
      buf = smallBuf;
    }

    used = size;
  }

  dbSmallBuffer()
  {
    used = 0;
    buf = smallBuf;
  }

  void put(size_t size)
  {
    if (size > SMALL_BUF_SIZE && size > used)
    {
      if (buf != smallBuf)
      {
        delete[] buf;
      }

      buf = new char[size];
      used = size;
    }
  }

  operator char*()
  {
    return buf;
  }

  char* base()
  {
    return buf;
  }

  ~dbSmallBuffer()
  {
    if (buf != smallBuf)
    {
      delete[] buf;
    }
  }
};


class FASTDB_DLL_ENTRY dbPooledThread
{

private:

  friend class dbThreadPool;

  dbThread                thread;
  dbThreadPool*           pool;
  dbPooledThread*         next;
  dbThread::thread_proc_t f;
  void*                   arg;
  bool                    running;
  dbLocalSemaphore        startSem;
  dbLocalSemaphore        readySem;

  static void thread_proc  pooledThreadFunc(void* arg);

  void run();
  void stop();

  dbPooledThread(dbThreadPool* threadPool);
  ~dbPooledThread();
};

class FASTDB_DLL_ENTRY dbThreadPool
{

  friend class dbPooledThread;
  dbPooledThread* freeThreads;
  dbMutex         mutex;

public:
  dbPooledThread* create(dbThread::thread_proc_t f, void* arg);
  void join(dbPooledThread* thr);
  dbThreadPool();
  ~dbThreadPool();
};

#endif // __SYNC_H__