Parallel.waitForAny

From ComputerCraft Wiki
Revision as of 06:26, 12 February 2014 by Bomb Bloke (Talk | contribs) (Some attempts at clarification.)

Jump to: navigation, search
Grid Redstone.png  Function parallel.waitForAny
Lets you run multiple functions at the same time, alternating between them until any happen to finish. Note that it takes function names as parameters (eg "function1", "function2", etc), as opposed to function calls (eg "function1()", "function2()", etc).

The functions are not actually executed simultaniously, but rather this API will automatically switch between them whenever they yield (eg whenever they call coroutine.yield(), or functions that call that - eg 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, most anything that causes the script to pause - eg sleep(), rednet.receive(), most of the turtle API, etc) can safely be used in one without affecting the event queue accessed by the other.
Syntax parallel.waitForAny(function1, function2, so on)
Returns A number indicating which function completed based on argument order
Part of ComputerCraft
API parallel

Examples

Grid paper.png  Example
Tells the computer to run function1 and function2 at the same time. Will broadcast what the user enters or prints what it receives over rednet, depending on what happens first.
Code
function1 = function()  -- Define function1.
 print (rednet.receive())
end

function function2()  -- Define function2.
 rednet.broadcast (read())
end

parallel.waitForAny (function1, function2)  -- Run both functions in parallel until one finishes.
Output Either it prints what it received via rednet, or it broadcasts the message the user typed.