How to use a Semaphore when Multithreading in Godot 3

In this video I go over what a semaphore is and also how you would use semaphores in Godot Engine to solve the Producer-consumer computing problem.

Timestamps:
0:00 Intro
0:33 Example 1
3:07 Producer-consumer problem
4:40 Example 2
10:15 Outro

Resources:

[baowei]

The examples and explanations were very clear. Love this video!!

[grundxgames]

I just found this and i must say you took my projects to another level with your tutorial. Thanks :)

[TheInsidiousTaco]

You just explained the producer consumer problem 10x better than the lecturer did in my Systems Programming class. Keep up the awesome content!!

[KrystofKlestil]

The timing of this video couldn't have been better. I recently put multithreading into my latest game and although I had a rough idea of semaphore and mutexes, and especially with semaphores, this video made it crystal clear.
Originally I had thought the threads are used in a different way, where one creates them only when necessary and then destroys them, although the uses I'm seeing are creating more threads from the get go, and keeping them alive/waiting/working throughout the entirety of your game loop.

[sslaxx]

This could be used to put together a proposal to enhance the existing docs.

[carl-johanhorberg]

GODOOOWD! Nice tutorial though. godough.

[GregX]

Wow! Amazing explanation! Two questions... Why do the consumers and producers wait so long to start consuming/producing (shenanigans) when not using the semaphores? Does it matter if you put the xxx_post() commands inside the mutex.lock/unlock vs. outside (like you have it)?

[Paruthi.]

Awesome tutorial.. is these features (threads, semaphore) in Godot work on all platforms (mainly android )?

[chromiumos]

hi

btw just for looks you can change these lines

produce function:
print("producer (", OS.get_thread_caller_id(), ") produced: (", x, ") in buffer at: (", buffer.size(), ")")

consume function:
var x = buffer.front()
buffer.pop_front()
print("consumer (", OS.get_thread_caller_id(), ") consumed: (", x, ") in buffer")

[solsticeprojekt]

Maybe you should also make a video about a ringbuffer, which I believe is a better way of solving the Producer/Consumer problem and doesn't require constant locking.

[artisanpixel]

talking too fast- doesn't give us time to understand what you're saying.