Visual C++ .NET/Thread/Lock

Interlocked Vars

 
#include "stdafx.h"
using namespace System;
using namespace System::Threading;
ref class MyThread
{
    static int iVal;
public:
    static MyThread()
    {
        iVal = 5;
    }
    void ThreadFunc();
};
void MyThread::ThreadFunc()
{
    while (Interlocked::Increment(iVal) < 15)
    {
        Thread ^thr = Thread::CurrentThread;
        Console::WriteLine("{0} {1}", thr->Name, iVal);
        Thread::Sleep(1);
    }
}

void main()
{
    MyThread ^myThr1 = gcnew MyThread();
    Thread ^thr1 = gcnew Thread(gcnew ThreadStart(myThr1, &MyThread::ThreadFunc));
    Thread ^thr2 = gcnew Thread(gcnew ThreadStart(myThr1, &MyThread::ThreadFunc));
    thr1->Name = "Thread1";
    thr2->Name = "Thread2";
    thr1->Start();
    thr2->Start();
}

lock demo

 
#include "stdafx.h"
#include <msclr/lock.h>
using namespace System;
using namespace System::Collections;
using namespace System::Threading;
using namespace msclr;
ref class App
{
private:
    ArrayList^ myArray;
public:
    App() { myArray = gcnew ArrayList(); }
    void Thread1()
    {
        while (true)
        {
            try
            {
                lock l1 (myArray->SyncRoot, 500);
                Console::WriteLine("In Thread 1 Lock");
                Thread::Sleep(1000);
            }
            catch(...) 
            {
                Console::WriteLine("Failed to get sync in Thread 1");
            }
        }
    }
    void Thread2()
    {
        lock l2(myArray->SyncRoot, lock_later);
        while (true)
        {
            if (l2.try_acquire(500))
            {
                Console::WriteLine("In Thread 2 lock");
                Thread::Sleep(1000);
                l2.release();
            }
            else
            {
                Console::WriteLine("Failed to get sync in Thread 2");
            }
        }
    }
};
int main(array<System::String ^> ^args)
{
    App^ app = gcnew App();
    Thread ^th1 = gcnew Thread(gcnew ThreadStart(app, &App::Thread1));
    Thread ^th2 = gcnew Thread(gcnew ThreadStart(app, &App::Thread2));
    th1->IsBackground = true;
    th2->IsBackground = true;
    th1->Start();
    th2->Start();
    Console::ReadLine();
    return 0;
}

Sync By RWLock

 
#include "stdafx.h"
using namespace System;
using namespace System::Threading;
ref class MyThread
{
    static ReaderWriterLock ^RWLock = gcnew ReaderWriterLock();
    static int iVal = 4;
public:
    static void ReaderThread();
    static void WriterThread();
};
void MyThread::ReaderThread()
{
    String ^thrName = Thread::CurrentThread->Name;
    while (true)
    {
        try
        {
            RWLock->AcquireReaderLock(2);
            Console::WriteLine("Reading in {0}. iVal is {1}",thrName, iVal);
            RWLock->ReleaseReaderLock();
            Thread::Sleep(4);
        }
        catch (ApplicationException^)
        {
            Console::WriteLine("Reading in {0}. Timed out", thrName);
        }
    }
}
void MyThread::WriterThread()
{
    while (iVal > 0)
    {
        RWLock->AcquireWriterLock(-1);
        Interlocked::Decrement(iVal);
        Console::WriteLine("Writing iVal to {0}", iVal);
        Thread::Sleep(7);
        RWLock->ReleaseWriterLock();
    }
}
void main()
{
    Thread ^thr1 = gcnew Thread(gcnew ThreadStart(&MyThread::ReaderThread));
    Thread ^thr2 = gcnew Thread(gcnew ThreadStart(&MyThread::ReaderThread));
    Thread ^thr3 = gcnew Thread(gcnew ThreadStart(&MyThread::WriterThread));
    thr1->Name = "Thread1";
    thr2->Name = "Thread2";
    thr1->IsBackground = true;
    thr2->IsBackground = true;
    thr1->Start();
    thr2->Start();
    thr3->Start();
    thr3->Join();
    Thread::Sleep(2);
}