I have an application that I'm working on that requires a couple of secondary threads, and each will be responsible for a number of file handles (at least 1, upwards of 10). The file handles are not shared amongst the threads, so I don't have to worry about one secondary thread blocking the other when selecting to see what is ready to read/write. What I want to be sure of is that neither of the secondary threads will cause the main thread to stop executing while the select/pselect call is executing.
I would imagine that this is not a problem - one would imagine that such things would be done in, say, a web server - but I couldn't find anything that specifically said "yes, you can do this" when I Googled. Am I correct in my assumption that this will not cause any problems?
For clarification, what I have looks something like:
Main thread of execution ( select() loop handling incoming command messages and outgoing responses )
Secondary thread #1 ( select() loop providing a service )
Secondary thread #2 ( select() loop providing another service )
As I previously mentioned, none of the file handles are shared amongst the threads - they are created, used, and destroyed within an individual thread, with the other threads ignorant of their existence.
No you don't have to worry about them blocking the main thread. I have used select in multiple threads in various projects. As long as they have distinct FDSETS then you're fine and each one can be used like an independent event loop.