Sergey Babkin wrote:
From: Julian Elischer <[EMAIL PROTECTED]>
Basically you shouldn't have a recursed mutex FULL STOP. We have a couple
of instances in the kernel where we allow a mutex to recurse, but they had to be
hard fought, and the general rule is "Don't". If you are recursing on
a mutex you need to switch to some other method of doing things.
e.g. reference counts, turnstiles, whatever.. use the mutex to create these
One typical problem is when someone holds a mutex
and needs to call a function that also tried to get the mutex.
The typical solution for it is to provide two versions of
this function, one expecting the mutex being already held
by the caller, the other being a wrapper that grabs the mutex and
then calls the actual worker function.
If that happens rather frequently, the better thing to do is assuming
that the lock is alredy held in the function (adding an assertion for
it) than acquiring/releasing before/after the function.
Attilio
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