Laboratory - 4
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Threading Concept
Threading in .NET
Multi-Threaded Socket
Example
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A thread is like a replication of a process but
each replication is still belonging to a same
process.
Operating system concept
◦ Thread – lightweight process
◦ Process – program in memory
◦ Program – set of instruction
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Thread share memory but process has its
own memory
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Example : SimpleThread.cs
Thread class
4 constructors
public
public
public
public
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Thread(ThreadStart)
Thread(ParameterizedThreadStart)
Thread(ThreadStart, int)
Thread(ParameterizedThreadStart, int)
Requires ThreadStart delegate for thread with no
parameter
Thread with parameter will require
ParameterizedThreadStart
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ThreadStart
class SomeClass
{
void SomeThreadMethod()
{
// Some task to be performed here
}
void NormalMethod()
{
ThreadStart ts = new ThreadStart(SomeThreadMethod);
Thread t = new Thread(ts);
t.Start();
}
}
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It seems that each thread runs concurrently
But in practice, the context switching
between threads are so fast, it appears
parallelism
The execution order of each thread is random
In some cases, we need to have a certain task
within a thread to be completed first before a
context switching is carried out.
For example: Race condition
(RaceCondition.cs)
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Many methods are available to initiate thread
synchronization.
In this class we will use three synchronization
technique:
◦ Lock
◦ Monitor
◦ Mutex
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Example (Source code are given)
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Previously, server can handle only one client
per time
We need to have a way to handle multiple
client connection
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In connection-oriented protocol, the
RemoteEndPoint property gets the EndPoint
containing the remote IP address and port
number to which the Socket is connected.
The RemoteEndPoint is set after a call to
either Accept or Connect.
It is not needed to put the whole socket
program within the threading method.
The part of the socket program requires to
run concurrently will only be in included in
multithreading method.
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Multi-Threaded Server
Start
Create Listener
Socket
Bind
No
Listen
Incoming
Connection
Yes
Threading
Create New
Socket
Create New
Thread
Receive
Send
Yes
Has More
No
Close Socket
Accept
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Listener Flow
No
Bind
Listen
Incoming
Connection
Yes
Create New
Socket
Accept
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Example: EchoServerMT.cs