Multithreading allows multiple tasks to be performed simultaneously by executing independent threads. There are two methods for creating threads in C#: using the Thread class or the thread pool. Threads have a lifecycle that includes creation, execution, and termination. Synchronization is used to coordinate thread access to shared resources using locks, and threads can communicate through wait/pulse methods that pause execution until notified of state changes. Potential issues like deadlocks can occur if threads indefinitely wait for each other.

1. MULTITHREADING

2. Definition
Threading: A thread is an independent execution path, able to run
simultaneously with other threads.
Multithreading: Multithreading is used to perform multiple tasks at the
same time.

3. Thread life cycle

4. Creation
• C# supports 2 methods to create threads
 Using the Thread class.
 Using the Thread pool.
Thread Class:
 A new thread object is created and a delegate is passed to the thread’s constructor.
Thread Pool:
 C# provides a pool of threads. Tasks can be assigned to the threads in the pool.

5. Thread Class:
Thread thread1 = new Thread(new ThreadStart(Thread1));
Thread thread2 = new Thread(new ThreadStart(Thread2));
//thread2.Priority = ThreadPriority.Highest;
thread1.Name = "First";
thread2.Name = "Second";
thread1.Start();
thread2.Start();

7. Synchronization:
lock (this)
{
for(int i=0;i<5;i++)
Console.WriteLine(“Current thread is {0} and value of i is {1} ”,Thread.CurrentThread.Name,i);
}

8. Thread Communication:

9. Wait() Method:
Releases the lock on an object and blocks the current thread until it reacquires
the lock.
Syntax: Monitor.Wait(object);
Pulse() Method:
Notifies a thread in the waiting queue of a change in the locked object's state.
Syntax: Monior.Pulse(object);

10. Deadlock:
 A deadlock is a situation where an application locks up because two or more activities are
waiting for each other to finish.
lock(lock1)
{
lock(lock2)
{…}
}