What is thread ?
Threads are typically created when you want a program to do two things at once.
invoked:
Thread.Sleep(1000);
and thus provides the thread with an opportunity to clean up any resources it might have allocated.
Threads are typically created when you want a program to do two things at once.
Starting Threads
The simplest way to create a thread is to create a new instance of the Thread class. The Thread constructor takes a single argument: a
delegate type. The CLR provides the ThreadStart delegate class specifically for this purpose, which points to a method you designate.
This allows you to construct a thread and to say to it "when you start, run this method." The ThreadStart delegate declaration is:-
public delegate void ThreadStart( );
delegate type. The CLR provides the ThreadStart delegate class specifically for this purpose, which points to a method you designate.
This allows you to construct a thread and to say to it "when you start, run this method." The ThreadStart delegate declaration is:-
public delegate void ThreadStart( );
Example for Creating Thread:
using System;
using System.Threading;
public class CreatingThread
{
static void Main(string[] args)
{
Thread MyThread = new Thread(new ThreadStart(ThreadProc));
MyThread.Start();
MyThread.Join();
}
protected static void ThreadProcess()
{
for (int i = 0; i < 100; i++)
{
Console.WriteLine(i);
}
}
} |
Creating a Thread of Execution:
using System;
using System.Threading;
class MyThread
{
public int count;
string thrdName;
public MyThread(string name) {
count = 0;
thrdName = name;
}
public void run()
{
Console.WriteLine(thrdName + " starting.");
do {
Thread.Sleep(500);
Console.WriteLine("In " + thrdName +", count is " + count);
count++;
} while(count < 10);
Console.WriteLine(thrdName + " terminating.");
}
}
public class MultiThread
{
public static void Main()
{
Console.WriteLine("Main thread starting.");
MyThread mt = new MyThread("Child #1");
Thread newThrd = new Thread(new ThreadStart(mt.run));
newThrd.Start();
do {
Console.Write(".");
Thread.Sleep(100);
} while (mt.count != 10);
Console.WriteLine("Main thread ending.");
}
} |
Joining Threads
To join thread1 (t1) onto thread2 (t2), write:
t2.Join( );
Joining the current thread to each thread in the collection in turn:
t2.Join( );
Joining the current thread to each thread in the collection in turn:
foreach (Thread myThread in myThreads)
{
myThread.Join( );
}
Console.WriteLine("All my threads are done."); |
Create multiple threads of execution
using System;
using System.Threading;
class MyThread
{
public int count;
public Thread thrd;
public MyThread(string name)
{
count = 0;
thrd = new Thread(new ThreadStart(this.run));
thrd.Name = name;
thrd.Start();
}
void run()
{
Console.WriteLine(thrd.Name + " starting.");
do
{
Thread.Sleep(500);
Console.WriteLine("In " + thrd.Name +", count is " + count);
count++;
} while(count < 10);
Console.WriteLine(thrd.Name + " terminating.");
}
}
public class MoreThreads {
public static void Main() {
Console.WriteLine("Main thread starting.");
MyThread mt1 = new MyThread("Child #1");
MyThread mt2 = new MyThread("Child #2");
MyThread mt3 = new MyThread("Child #3");
do
{
Console.Write(".");
Thread.Sleep(100);
} while (mt1.count < 10 || mt2.count < 10 || mt3.count < 10);
Console.WriteLine("Main thread ending.");
}
} |
Suspending Threads
To cause your thread to sleep for one second, you can invoke the static method of Thread, Sleep, which suspends the thread in which it is invoked:
Thread.Sleep(1000);
Killing Threads
For killing a thread Abort( ) method is used. This causes a ThreadAbortException exception to be thrown, which the thread can catch,and thus provides the thread with an opportunity to clean up any resources it might have allocated.
catch (ThreadAbortException)
{
Console.WriteLine("[{0}] Aborted! Cleaning up...",
Thread.CurrentThread.Name);
}Example for Suspending, resuming, and stopping a thread:
using System;
using System.Threading;
class MyThread {
public Thread thrd;
public MyThread(string name) {
thrd = new Thread(new ThreadStart(this.run));
thrd.Name = name;
thrd.Start();
}
void run() {
Console.WriteLine(thrd.Name + " starting.");
for(int i = 1; i <= 1000; i++) {
Console.Write(i + " ");
if((i%10)==0) {
Console.WriteLine();
Thread.Sleep(250);
}
}
Console.WriteLine(thrd.Name + " exiting.");
}
}
public class SuspendResumeStop {
public static void Main() {
MyThread mt1 = new MyThread("My Thread");
Thread.Sleep(1000); // let child thread start executing
mt1.thrd.Suspend();
Console.WriteLine("Suspending thread.");
Thread.Sleep(1000);
mt1.thrd.Resume();
Console.WriteLine("Resuming thread.");
Thread.Sleep(1000);
mt1.thrd.Suspend();
Console.WriteLine("Suspending thread.");
Thread.Sleep(1000);
mt1.thrd.Resume();
Console.WriteLine("Resuming thread.");
Thread.Sleep(1000);
Console.WriteLine("Stopping thread.");
mt1.thrd.Abort();
mt1.thrd.Join(); // wait for thread to terminate
Console.WriteLine("Main thread terminating.");
}
} |
SynchronizationSynchronization is provided by a lock on the object, which prevents a second thread from barging in on your
object until the first thread is finished with it.
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