1. Multithread Programming
Why Multiple Threads?
Processes vs. Threads
Threads vs. Functions (Processes vs. Programs)
Thread States (Unstarted, Running, WaitSleepJoin, SuspendRequested, Suspended, AbortRequested, Aborted, StopRequested, Stopped)
Thread Priority (Highest, AboveNormal, Normal, BelowNormal, Lowest)
Thread Scheduling
Thread Synchronization

2. execution trace
concurrent I/O operation
interrupt handler (routine)

3. Take the previous GUI lectures and Proj #3 as an example,
Form1 and myDialog.
Multitasking the program? (Can we work on two additions simultaneously?)
(of course, if we invoke MyDialog in a non-blocked way)
Multithreaded programming:
Split a program into multiple segments (with beginning and ending points)
Run some of them concurrently
On a single processor (CPU) machine, time-sharing by multiple threads
True for multi-core, Hyper-Threading

4. Multithreading on a Uniprocessor interleaving of multiple threads within multiple processes
On a uniprocessor, multiprogramming enables the interleaving of multiple threads within multiple processes.
In the example,
- three threads in two processes are interleaved on the processor.
- Execution passes from one thread to another either when the currently running thread is blocked or its time slice is exhausted.

5. Execution states of a thread

6. Using Threads in C++/CLI
Method One
Create a task
Create a thread to associate with the task
Start the thread
Wait for a thread to end
Runs in foreground or background
Create an instance of thread. Use a delegate ParameterizedThreadStart to place the method to be the thread
Start() the thread
A thread can Sleep()
Thread:: Sleep(2000); // 2000 milliseconds
One thread waits for another thread to finish before continuing, Join()

7. Using Threads in C++/CLI
Method Two: thread pool
Create a task
Queue the task to the thread pool
Thread pool is system-managed, easy to use.
Run in background, so the main needs to remain alive
Add to the pool: ThreadPool::QueueUserWorkItem() //true if added
Takes WaitCallback() delegate (so to run your thread task)
Takes an Object handle (so to pass info to the thread task)

8. Examples