Thread Synchronization with Events

Here is an example of using Event with multiple threads for Thread Sync.

Event.h

//Example from http://www.relisoft.com/Win32/active.html
#if !defined _EVENT_H_
#define _EVENT_H_

class Event
{
public:
  Event ()
  {
    // start in non-signaled state (red light)
    // auto reset after every Wait
    _handle = CreateEvent (0, FALSE, FALSE, 0);
  }

  ~Event ()
  {
    CloseHandle (_handle);
  }

  // put into signaled state
  void Release () { SetEvent (_handle); }
  void Wait ()
  {
    // Wait until event is in signaled (green) state
    WaitForSingleObject (_handle, INFINITE);
  }
  operator HANDLE () { return _handle; }

private:
  HANDLE _handle;
};

#endif 

Thread.cpp

//Program tested on Microsoft Visual Studio 2008 - Zahid Ghadialy
//This shows example of Multithreading, thread sync, Events
#include <windows.h>
#include <process.h>
#include <iostream>
#include "Event.h"

using namespace std;

void Func1(void *);
void Func2(void *);

Event _event; //Create an event

int main()
{
  HANDLE hThreads[2];

  //Create two threads and start them
  hThreads[0] = (HANDLE)_beginthread(Func1, 0, NULL);
  hThreads[1] = (HANDLE)_beginthread(Func2, 0, NULL);

  //Makes sure that both the threads have finished before going further
  WaitForMultipleObjects(2, hThreads, TRUE, INFINITE);

  cout << "Main exit" << endl;
  return 0;
}

void Func1(void *P)
{
  int Count = 0;

  for (;;)
  {
    _event.Wait();
    do //This loop will only start when Event is triggered
    {
      cout<<"Func1: Count = "<<Count++<<endl;
    }while(Count < 10);
    return;
  }

  return;
}

void Func2(void *P)
{
  for(int i = 0; i < 10; i++)
  {
    cout<<"Func2: i = "<<i<<endl;
  }
  //Release the event so Thread1 (Func1) can start
  _event.Release();
  return;
}

You can also have a look at this example here which uses Event, Mutex, etc.

The output is as follows: