Goroutines in R Programming Language

Based on the input, the target language is Python. Below is the translated code and explanation in Markdown format suitable for Hugo.

A goroutine is a lightweight thread of execution.

import time
import threading

def f(from_where):
    for i in range(3):
        print(f"{from_where} : {i}")

if __name__ == "__main__":
    f("direct")

    threading.Thread(target=f, args=("thread",)).start()

    threading.Thread(target=lambda msg: print(msg), args=("going",)).start()

    time.sleep(1)
    print("done")

Suppose we have a function call f("direct"). Here’s how we’d call that in the usual way, running it synchronously.

f("direct")

To invoke this function in a separate thread, use threading.Thread(target=f, args=("thread",)).start(). This new thread will execute concurrently with the main one.

threading.Thread(target=f, args=("thread",)).start()

You can also start a thread for an anonymous function call.

threading.Thread(target=lambda msg: print(msg), args=("going",)).start()

Our two function calls are running asynchronously in separate threads now. Wait for them to finish (for a more robust approach, use a threading mechanism like threading.Event or similar concepts).

time.sleep(1)
print("done")

When we run this program, we see the output of the blocking call first, then the output of the two threads. The threads’ output may be interleaved because threads are being run concurrently by the Python runtime.

$ python goroutines.py
direct : 0
direct : 1
direct : 2
thread : 0
going
thread : 1
thread : 2
done

Next, we’ll look at a complement to threads in concurrent Python programs: queues.