----- Original Message ----- From: "Anthony Williams" <anthony_w.geo@yahoo.com> To: <boost@lists.boost.org> Sent: Thursday, May 08, 2008 2:35 PM Subject: Re: [boost] Review Request: future library (N2561/Williams version)
"vicente.botet" <vicente.botet@wanadoo.fr> writes:
----- Original Message ----- From: "Anthony Williams" <anthony_w.geo@yahoo.com> To: <boost@lists.boost.org> Sent: Tuesday, May 06, 2008 8:42 AM Subject: Re: [boost] Review Request: future library (N2561/Williams version)
"vicente.botet" <vicente.botet@wanadoo.fr> writes:
why we don't need to protect get_future() function of multiple thread access?
By design you can only call this function once, so if multiple threads called it concurrently and that was safe, only one would get the future, and the other would get an exception. The user should therefore use appropriate synchronization to ensure correct results anyway, so making this call thread-safe would not be of benefit.
I don't understand the need of this function. Could you show a use case for promise::get_future() function?
promise::get_future() is the only way to get a future from a promise. Since the whole point of using promise is to get the future, it's rather pointless without it.
why this is not an internal feautre?
Were you getting at something else?
Sorry, but I thouth that it is up to the promise to communicate with his future when the user do a set_value or set_exception or elsewhere When the user will need the future of a promise? Vicente