API Reference - uv.loop

The loop module provides direct control over the libuv event loop.

loop.run()

Run the libuv event loop. This is only necessary if an I/O request was created in a coroutine without the event loop already running. Requests made outside a coroutine are performed synchronously. It returns when the last I/O request is finished.

print(uv.fs.readfile('README.md'))

In this example, we're not in a coroutine, so fs.readfile ran the event loop implicitly. There is no need to call loop.run().

coroutine.resume(coroutine.create(function()
  print(uv.fs.readfile('README.md'))
end))
loop.run()

Here, we manually created a coroutine that called fs.readfile, which yielded while awaiting the result. The event loop is not running, so unless we called loop.run(), the program would exit without performing the I/O request and the coroutine would never resume.

loop.alive()

Check whether the libuv event loop is running.

loop.stop()

Stop the libuv event loop.

loop.idle(callback)

Call callback continuously while the event loop has nothing else to do.

loop.yield(callback)

Call callback each time Lua yields control to the event loop.

loop.resume(callback)

Call callback each time Lua resumes control from libuv.