MyThread | User mode thread implementation

// What I want is for one thread to try to call methodB() while the other thread is in methodB() trying to call methodA().

That's not a deadlock. The thread that's trying to call methodB() simply will be forced to wait until the other thread releases the lock by returning from its methodB() call.

To get a classic deadlock, you need to have two locks. Your program has only one lock—the intrinsic lock belonging to the single instance of SharedObject that your program creates.

A classic deadlock is when one thread has already acquired lock A and is waiting to acquire lock B while the other thread has acquired lock B, and it's waiting to acquire lock A. In that case, neither thread can make progress until the other thread releases its lock. But, neither thread will release its lock because neither thread can make progress.

You need two locks. You have two methods (methodA() and methodB()), but they both lock the same lock.

In the command nvidia-smi -l 1 --query-gpu=memory.used --format=csv

the -l stands for:

-l, --loop= Probe until Ctrl+C at specified second interval.

So the command:

1 - main thread is so fast that the child thread did not have been started (or finish being started) - maybe a yield in main would eventually help the child thread to get a chance to run. (and increasing from 10 to 100or more iterations)

2 - yield does not guarantee that another thread will run (from documentation: "The scheduler is free to ignore this hint.") _{Not so relevant since there is no yield in main}

3 - check the java.util.concurrent.locks package.
^{actually the yield documentation also states "It is rarely appropriate to use this method."}

In your first example, you are not starting a thread at all. You are calling the run() function in your main thread, where it blocks. To start the thread, you need to call

You are using threads incorrectly. If you inherit QThread, you should only call start() from main thread and in QThread's run() method place all operations, if you call thread methods from main thread they got executed in main thread (myThread.read() runs in main thread and blocks event loop until return from read()).

Create a signal

I will share a solution which is done by busy waiting. To improve it you can check CyclicBarrier structure. It returns 36 as sum.

If you change the priority of a thread that has already run, it has no effect. For example:

Ok, actually it seems I was wrong.