On Mon, Nov 23, 2009 at 10:08 AM, Vicente Botet Escriba <vicente.botet@wanadoo.fr> wrote:
Hi,
I don't know if I have already requested that but ...
Is there any deep reason to don't provide the equivalent of the free functions lock, try_lock
Non-member function lock(Lockable1,Lockable2,...) Non-member function lock(begin,end) Non-member function try_lock(Lockable1,Lockable2,...) Non-member function try_lock(begin,end)
to unlock multiple lockables?
Non-member function unlock(Lockable1,Lockable2,...) Non-member function unlock(begin,end)
Probably because locking order can cause deadlocks if the order is different for each locker, but unlocking does not. I assume that the multi-arg locking functions are a way to ensure that there is a globally-defined lock ordering (usually implemented by sorting according to address of mutex). Since unlocking does not have deadlock problems due to unlocking order, it was probably deemed unnecessary to have multi-arg unlocking. Of course, now that you mention it, a multi-unlock would probably be somewhat convenient in a few cases. Sincerely, AmkG