Anthony Williams wrote:
Stefan Seefeld <seefeld@sympatico.ca> writes:
David Abrahams wrote:
Seems to me that if we have "detach()," it we should be asking whether a thread is "attached()," rather than "joinable()." Our documentation
Agreed.
says "if *this refers to a thread of execution..." all over it, which would seem to indicate that joinable() is an important question even when you're not about to join().
I find this phrasing a bit strange. 'thread of execution' sounds like a concept. Is the 'main' thread not a 'thread of execution' ? (And even if no threads are spawned at all ?)
The 'main' thread us a thread of execution, even if no other threads have been spawned. You cannot obtain a boost::thread object that references it though.
I was looking for alternative ways to phrase the "Effects" (in particular to express the "joinable" concept, but ran into some issues: * There doesn't appear to be any means to query a thread object's state. * I can (apparently) invalidate an existing thread object by detaching it. * I can construct a thread that doesn't refer to anything (default constructor). Of course there is 'joinable', but that doesn't let me distinguish between a default-constructed ("not-a-")thread, a detached thread, and a thread that has already been joined. Anthony Williams wrote:
David Abrahams <dave@boostpro.com> writes:
Seems to me that if we have "detach()," it we should be asking whether a thread is "attached()," rather than "joinable()." Our documentation says "if *this refers to a thread of execution..." all over it, which would seem to indicate that joinable() is an important question even when you're not about to join().
Thoughts?
"attached()" seems a good name to me. Just about every member function of boost::thread requires that the thread is joinable() for it to have any meaning.
Now that you have clarified the meaning of 'joinable' (thanks !), I think 'attached' is not a synonym for it. thread t(task); ... t.join(); ... assert(t.attached() == false); // doesn't sound right, does it ? FWIW, Stefan -- ...ich hab' noch einen Koffer in Berlin...