Didier Kryn <kryn@???> writes:
> Le 24/07/2016 22:31, Rainer Weikusat a écrit :
>> Didier Kryn <kryn@???> writes:
>>> Le 22/07/2016 18:21, Brian Nash a écrit :
>>>> For example, when I discovered multithreading, all my programs used it
>>>> in some way, even when it was unnecessary.
>>> I sometimes use multithreading, but never mutexes. Mutex can be
>>> harmless if there's only one. Otherwise better use select()/poll() or
>>> you'll waste time or even dead-lock. It's amazing how the old select()
>>> paradigm is so much better than the modern mutex. I see mutex as an
>>> invention to relieve the programmer from thinking.
>> One of the advantages of having more than one thread of execution
>> running in the same address space is that these can communicate with
>> each other without going through the kernel. And 'a mutex' is just a
>> basic primitive for implementing this.
>

>     I thought mutexes were implementing through a kernel object known
> as futex.

Sleeping on a contended mutex is implemented in this way. But that's
supposed to be an exceptional case.