Re: [Boost-users] [asio] multi-threaded io_service::run produce wrong result

On Tue, Mar 29, 2011 at 06:49:12AM +0800, leiming wrote:

在 Tue, 29 Mar 2011 02:40:48 +0800，Lars Viklund 写道:

...

On Mon, Mar 28, 2011 at 08:40:02PM +0800, leiming wrote:

...

Hi, there.

An io_service will consider itself finished when there is no more pending tasks to perform.

Thank you for your reply!

...

That means that if there is sufficient time between the first task and the second task being posted, they may return from run() and end their threads, resulting in the joins being completed. I'm also run io_service::run in the main thread after add all jobs but it still produce a wrong answer. It will finish all jobs even if the 2 threads ended because the jobs will run in the main thread after all jobs were added I thought. I don't know why

I do not quite know why, but I would guess that once an io_service has gone into the stopped state, you might have to perform some action to reset it, so that it can be started again. I would not expect any actions you post to it during the stopped-but-not-reset period to have any effect.

...

If you want to keep an io_service alive while there are no pending operations, construct an io_service::work object from the io_service.

That will keep io_service::run() running until all pending work is finished (which you will indicate by destroying the work object.

I have tried and it works!

Hooray! -- Lars Viklund | zao@acc.umu.se