running()

running() returns a reference to the current coroutine and a boolean that indicates if the execution is currently in the main coroutine.

Syntax

coroutine.running()

• running() function in Lua which returns the coroutine running the function. If the function is not running inside a coroutine, it returns nil.
• There are several coroutine functions used to manage these objects, including create(), which creates new coroutines, and yield(), which allows a running coroutine to suspend its execution so that it can be resumed later.

Example

This example uses coroutine.running() to print coroutine IDs, both from the main thread and within a coroutine.

function printCurrentCoroutineID()
  local currentCoroutine = coroutine.running()
  if currentCoroutine then
    print("Current coroutine ID:", currentCoroutine)
  else
    print("Not running inside a coroutine")
  end
end

print("Printing from the main thread")
printCurrentCoroutineID()

-- Create a coroutine and print from it
local myCoroutine = coroutine.create(function()
  print("Printing from the coroutine")
  printCurrentCoroutineID()
end)

coroutine.resume(myCoroutine)

The output will be similar to:

Printing from the main thread
Current coroutine ID: thread: 0x55eed07642a8
Printing from the coroutine
Current coroutine ID: thread: 0x55eed076bbf8