Re: Recursive mutexes?

[Rob Browning]

Neil Jerram <address@hidden> writes:

> Win32 has this: `WaitForMultipleObjects'.  Can it be done in a POSIX
> system without polling?

Yes, I think so -- if you let a helper thread (or threads) handle
watching for whatever events the user threads are interested in.  The
watcher thread(s) then signals a condition variable (or semaphore or
whatever) that the user thread is blocked on whenever an event the
user thread is interested in arrives.

Whether you have one watcher thread or many, and whether you break
them up by type or not (say one for POSIX IO, one for GTK, one for
KDE), depends on implementation details.

This presumes that the events that the helper thread(s) will be
watching can be waited on without polling, but even if polling is
required, it can be limited to the relevant watcher thread(s).

-- 
Rob Browning
rlb @defaultvalue.org, @linuxdevel.com, and @debian.org
Previously @cs.utexas.edu
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