Re: [Twisted-Python] Control the number of parallel system calls

Andrew Bennetts wrote:

Daniel de la Cuesta wrote:

...

Hi,

I am developing a video conversion server. To process the video conversion I use the method "getProcessOutput" to call "ffmpeg".

The user upload the video using a HTTP POST and each video must be converted to 8 or 10 output formats.

Currently, all the conversions for each video are processed in parallel, what I want to do is to control the number of parallel system calls to "ffmpeg". For example I only want 2 processes at the same time and when one of them finishes the next process start.

How can I do that?

Is there any function in Twisted that implements that?

The obvious way to do that would be using a twisted.internet.defer.DeferredSemaphore.

Or http://foss.eepatents.com/AsynQueue ... :-)