What's the difference between boost::io_service poll_one and run_one?

Question

io_service::poll_one Run the io_service object's event processing loop to execute one ready handler.

vs

io_service::run_one Run the io_service object's event processing loop to execute at most one handler.

From that explanation it would seem poll_one could execute more than one handler? Does run_one or poll_one use any thread that's called run() or only the thread that calls poll_one/run_one?

The documentation for ASIO is very sparse.

one executes one READY handler, the other executes one handler (ready or not). — akappa, Jan 04 '12 at 13:22
ok, what's the distinction between a READY handler and one that's not? — Eloff, Jan 04 '12 at 13:26
if you have a socket and the handler's job is to read something out of it, then a ready handler is one which is attached to a non-empty socket (so you don't have to wait for the data to come from the net) — akappa, Jan 04 '12 at 13:29

Cătălin Pitiș · Accepted Answer · 2012-01-06T06:47:29.503

17

poll_one will return immediately (non-blocking) in case there is no event to process.

run_one will block the calling thread until one event is ready to process.

You could also check some documentation here

edited Jan 06 '12 at 06:47

answered Jan 04 '12 at 14:27

Cătălin Pitiș

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So the documentation for run_one should read "blocks until it executes exactly one handler" vs "executes at most one handler"? – Eloff Jan 04 '12 at 15:23
It's confusing. "At most" here implies 0..1 but if it blocks until it processes an event, when can it ever return having processed 0 events? – Eloff Jan 04 '12 at 22:33
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In case the service is closed. – Cătălin Pitiș Jan 05 '12 at 06:03

What's the difference between boost::io_service poll_one and run_one?

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