thread.cpp

一个通用的oracle OCI开发程序包

#include <iostream.h>
#include <process.h>
#include <stdlib.h>
#include <stdio.h>

#include <math.h>
#include <time.h>
#include <memory>

#include <stdinc.h>

#include <afxmt.h>

// thread.cpp.
// Demonstrates OCI++ in a multithreaded environment, accessing an Oracle Server to 
// perform a read and a write operation simultaneously.
// Ensure Project->Settings->General->Microsoft Foundation Classes = Use MFC in a shared DLL

// MFC specific thread management

// See Bottom of file for DDL statements.

// Thread stuff...
CRITICAL_SECTION critical_section;
static int ActiveThreadCounter = 0;

// Thread counters. Increment and decrement need mutually exclusive access, hence
// the use of EnterCriticalSection and LeaveCriticalSection (Win32 specific)
void IncCount(int& Counter)
{
  EnterCriticalSection(&critical_section);
  Counter++;
  LeaveCriticalSection(&critical_section);
}
void DecCount(int& Counter)
{
  EnterCriticalSection(&critical_section);
  Counter--;
  LeaveCriticalSection(&critical_section);
}

// Read objects from database
void read_obj(void* pParam);

// Write objects to database
void write_obj(void* pParam);

// Initialise threads
void init_thread();

void main()
{
  init_thread();
}

void init_thread()
{
  InitializeCriticalSection(&critical_section);

  // create 10 threads to write objects, and 10 threads to read objects
  for(int i = 0; i < 10; i++)
  {
    ::IncCount( ActiveThreadCounter ); _beginthread(write_obj, 4096, (void*)i);
    ::IncCount( ActiveThreadCounter ); _beginthread(read_obj, 4096, (void*)i);

  }

  while( ActiveThreadCounter != 0 ){ /* Wait for all threads */ }
  
}

void read_obj(void* pParam)
{
  try
  {

    COCISession s;
    // connect to server
    s.connect("temp/temp",OCI_OBJECT | OCI_THREADED);

    cout << "<<< Read start >>>\n";
    cout.flush();

    std::vector<COCIObject> objs;
    COCIStatement stmt(s);
    stmt = "select ref(r) from m r";
    std::vector<COCIRef> refs(100, COCIRef(s));
    stmt.define(1,refs);
    if(stmt.execute())
    {
      do
      {
        objs = COCIObject::array_pin(refs);
        for(std::vector<COCIObject>::iterator itr = objs.begin(); itr != objs.end(); itr++)
        {
          //cout << (int)itr->get("id") << "," << flush;
          
        }
      }while(stmt.fetch());
      //cout << endl << flush;

    }

    cout << "<<< Read end >>>\n";
    cout.flush();  
  }
  catch(CBaseException& exc)
  {
	  char* buff = exc.GetError();
 	  cout << buff << endl;
    cout.flush();
  }


  ::DecCount( ActiveThreadCounter );
}

void write_obj(void* pParam)
{

  try
  {

    COCISession s;
    s.connect("temp/temp",OCI_OBJECT | OCI_THREADED);
    cout << "<<< Write start >>>\n";
    cout.flush();


    COCICache c(s);

  
    COCIObject m(s, COCITable(s, "M"), COCIType(s, "M_T"));
    m.set("id",(int)pParam);

    // Copy m, 99 times => 99 + 1 objects get put on database
    std::vector<COCIObject> objs(99, m);

    c.flush();
  

    cout << "<<< Write end >>>\n";
    cout.flush();
  }
  catch(CBaseException& exc)
  {
	  char* buff = exc.GetError();
 	  cout << buff << endl;
    cout.flush();
  }

  ::DecCount( ActiveThreadCounter );
}


// DDL
// create type m_t as object (id number);
// create table m of m_t;