EnterCriticalSection doesn't seem to block

I have the following code to create threads to do some work (with details omitted for clarity).

 CRITICAL_SECTION gCS;

 class Locker
 {
     public:
    Locker(CRITICAL_SECTION& cs): m_cs(cs)
     {
         EnterCriticalSection(&m_cs);
     }
     ~Locker()
     {
         LeaveCriticalSection(&m_cs);
     }
     private:
        CRITICAL_SECTION  m_cs;
 };

 ...

 HRESULT MyClass::FinalConstruct()
 {
   InitializeCriticalSection(&gCS);
 }

 ...

 DWORD WINAPI MyClass::CreateThread()
 {

        hWriteReceiptThread = CreateThread( 
                NULL,                   // default security attributes
                0,                      // use default stack size  
                MyClass::RunThread,       // thread function name
                NULL,          // argument to thread function 
                0,                      // use default creation flags 
                &dwThreadId);   // returns the thread identifier 
        return 0;
 }


 DWORD WINAPI MyClass::RunThread(LPVOID args)
 {
        {
                LogInfo("getting lock for critical Section");
                Locker lock(gCS);
                EnterCriticalSection(&gCS);
                LogInfo("entered Critical Section");

         //... do lots of stuff

                LogInfo("leaving critical section");
                LeaveCriticalSection(&gCS);
                LogInfo("left critical section");
        }
 }

      

        
        
        
      

    

At startup, the following print instructions are executed (each print statement prints the number returned with a GetCurrentThreadId()

pre-statement. It looks like the critical section has no effect. For example, thread 7608 acquires the lock and then the next two threads also acquire the lock until it completes. Can anyone- Anyone explain how this can happen?

 16004 Critical section initialised
 7608 getting lock for critical Section
 7608 Entered Critical Section
 11412 getting lock for critical Section
 11412 Entered Critical Section
 12860 getting lock for critical Section
 6552 getting lock for critical Section
 6552 Entered Critical Section
 5524 getting lock for critical Section
 5524 Entered Critical Section
 7608 leaving critical section
 7608 left critical section

      

        
        
        
      

    

thank