Re: [ECOS] Mutex & Asserts during initialisation

[Fabian Scheler <fabian.scheler@gmail.com>]

Hi,

> > Humm, i think this is reasonable behaviour. Anything that tries to use
> > a mutex must assume it can block. Otherwise why are you using a mutex!

well, this is a reasonable solution,

> I can see the other side of this. You want to write a driver that can work
> in a multi-threaded environment, so you include a mutex in it. But then you
> want to call it from startup code. Rather than write a second specialized
> non-multi-threaded driver, or include some sort of flag that tells it to
> skip the locking and unlocking, it's much cleaner to simply consider the
> attempt to lock a mutex before the threading system has been initialized a
> harmless null operation.

while this is not. You better should design your driver properly, so
it can cooperate with the operating system, the driver is developed
for, not vice versa. Within a clean layered software design it just
means to add one more layer to make your driver thread safe! During
startup you can still use a layer where no thread synchronization is
necessary. You can add this new layer with the help of C++
inline-functions in a very efficient manner, for example. Another
possibility is to use AOP for this purpose, compare "Using AOP to
Develop Archtiecture-Neutral Operating System Components"
(Spinczyk+Lohmann), for instance.

Ciao, Fabian

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