RE: Question about select and poll system call

From: David Laight
Date: Thu Mar 16 2023 - 05:34:37 EST


From: richard clark
> Sent: 16 March 2023 00:57
>
> On Wed, Mar 15, 2023 at 4:59 PM David Laight <David.Laight@xxxxxxxxxx> wrote:
> >
> > > 2. Can we unify the two different system calls? For example, using
> > > poll(...) to implement the frontend select call(...), is there
> > > something I'm missing for current implementation? The Cons and Pros,
> > > etc
> >
> > The underlying code that implements them is common.
> >
> > Beware that the glibc select() wrappers have their own limit
> > on the highest fd.
> > Exceeding that limit (probably 1024) will cause buffer overruns
> > in the application (One of the Android apps I uses crashes that way).
>
> Ah, interesting. Seems glibc doesn't make that limit from my testing
> code snippet in last email...

Look at the FD_SET() macros....

David

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