Re: Mutex/Lock
On 2 Jun., 23:48, Szabolcs Ferenczi <szabolcs.feren...@gmail.com>
wrote:
On Jun 2, 11:05 pm, peter koch <peter.koch.lar...@gmail.com> wrote:
On 2 Jun., 20:27, Szabolcs Ferenczi <szabolcs.feren...@gmail.com>
wrote:
On Jun 2, 6:33 am, "Chris Thomasson" <cris...@comcast.net> wrote:
"Szabolcs Ferenczi" <szabolcs.feren...@gmail.com> wrote in message
[...]
All[s] you said was that
starting threads in ctors is no big deal if you know what your doing=
..
Correct. And I still hold that claim. Your friend and you were trying
to contradict that but you failed.
Well,
the OP was on the verge of making a mistake, and I felt the need to =
put up a
big warning sign. So be it.
You have given a false warning. That is it.
No. That warning was not false.
If that was not false, you are invited to prove the claim.
It is easy to point to the numerous classes created by inexperienced
people where the code turns up to not work correctly, and that is all
it takes to give a warning. This is what a warning is all about: there
is nothing in the statement that tells that correctly working code is
impossible to get to work correctly, and in particular no claim that
such code can't be created.
Dealing with threads is not
straightforward, and you have to be at least a little bit careful.
Yes, that is why you should get rid of the low level stuff you are
fully supporting in the other discussion threads about threading in C+
+0x just because you are not educated enough in concurrent
programming.
What low-level code did I support? I do not remember having argued
about using low-level constructs. On the contrary, I have always
supporting using high-level constructs.
[...]
"Member functions, including virtual functions (10.3), can be called
during construction or destruction"
This is true, of course. But you have to be careful: when calling a
virtual function you call the function of the currently creating type,
not the final virtual function. So you can't get your thread to work
on the data of the resulting function.
I was talking about disciplined usage all along. Your hacker friends
came with absurd constructions so you are really warning them.
[...]
Lots of stuff is not an error according to language-rules. Still,
theres a lot of rules outside of the pure language that you better
follow that you should follow unless you really know what you are
doing (and in that case, you probably won't violate them because you
know a better way of getting things done).
So I really know what I am doing and I can reason about it as well. On
the other hand you and your mates here cannot prove that claim about
incomplete object or not fully constructed object thing. So what are
you talking about?
The
active<T> template gets around that limitation by acting as a proxy.=
It
works very well.
Agreed. So you nicely contradict yourself since you start the thread
in the constructor of the proxy and according to your own reasoning
the object is `not fully constructed' yet. Formally speaking. Or do
you think that in this case you know what you are doing and you can
fake your own principle?
In that case, the object the thread works on will be fully
constructed, so theres not a problem here (I do not know the code of
active<T>, but I presume this is the case.
You do not really follow the discussion, do you? The pointer has been
given a couple of posts before:http://groups.google.com/group/comp.lang.c+=
+/msg/20c14991f9e88482
I haven't read all posts, but I do not see how Thomassons active-
template is relevant to these posts: again, I never did claim that
writing a thread-wrapper class is impossible - only that it is not
easy to get correct. Also, I don't believe that you can have a generic
template-class that will work without using template code, and this is
just one more reason to warn newbies against creating such a class.
This certainly is the case
in my thread templateclass).
So you contradict yourself too if you object me since you just claimed
you do what you are just opposing.
Again, I never did oppose that.
Let me ignore your personal stuff at the end of your mail. Please try
to be professional.
Even better: why don't you try to get professional - e.g. by providing
something useful to this group. Let me recommend that you post a class
that works correctly and provides the needed functionality. It should
be quite a simple job according to yourself.
/Peter