parallel

A simple way to run several functions at once.

Functions are not actually executed simultaneously, but rather this API will automatically switch between them whenever they yield (e.g. whenever they call coroutine.yield, or functions that call that - such as os.pullEvent - or functions that call that, etc - basically, anything that causes the function to "pause").

Each function executed in "parallel" gets its own copy of the event queue, and so "event consuming" functions (again, mostly anything that causes the script to pause - eg os.sleep, rednet.receive, most of the turtle API, etc) can safely be used in one without affecting the event queue accessed by the other.

caution

When using this API, be careful to pass the functions you want to run in parallel, and not the result of calling those functions.

For instance, the following is correct:

local function do_sleep() sleep(1) end
parallel.waitForAny(do_sleep, rednet.receive)

but the following is NOT:

local function do_sleep() sleep(1) end
parallel.waitForAny(do_sleep(), rednet.receive)

Changes

waitForAny(...)Switches between execution of the functions, until any of them finishes.
waitForAll(...)Switches between execution of the functions, until all of them are finished.
waitForAny(...)Source

Switches between execution of the functions, until any of them finishes. If any of the functions errors, the message is propagated upwards from the parallel.waitForAny call.

Parameters

  1. ... function The functions this task will run

Usage

  • Print a message every second until the q key is pressed.

    local function tick()
    while true do
        os.sleep(1)
        print("Tick")
    end
end
local function wait_for_q()
    repeat
        local _, key = os.pullEvent("key")
    until key == keys.q
    print("Q was pressed!")
end

parallel.waitForAny(tick, wait_for_q)
print("Everything done!")
waitForAll(...)Source

Switches between execution of the functions, until all of them are finished. If any of the functions errors, the message is propagated upwards from the parallel.waitForAll call.

Parameters

  1. ... function The functions this task will run

Usage

  • Start off two timers and wait for them both to run.

    local function a()
    os.sleep(1)
    print("A is done")
end
local function b()
    os.sleep(3)
    print("B is done")
end

parallel.waitForAll(a, b)
print("Everything done!")