| Topic: |
DEVELOP > c-Plus-Plus |
| User: |
"Koo" |
| Date: |
20 Dec 2003 04:34:10 AM |
| Object: |
Blocking functions |
How do you create your own blocking function?
Koo
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| User: "Mike Wahler" |
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| Title: Re: Blocking functions |
20 Dec 2003 01:23:38 PM |
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"Koo" <iostream_h@hotmail.com> wrote in message
news:32c6afe6.0312200234.26bb8868@posting.google.com...
How do you create your own blocking function?
Here, use mine.
void block()
{
for(;;)
}
-Mike
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| User: "EventHelix.com" |
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| Title: Re: Blocking functions |
20 Dec 2003 03:53:18 PM |
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Any function that invokes a blocking OS primitive is a blocking
function.
If you wish to write a function that will not return until
a specific condition is met, use blocking semaphore calls to
implement such a function.
Sandeep
--
http://www.EventHelix.com/EventStudio
EventStudio 2.0 - Go Beyond UML Use Case and Sequence Diagrams
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| User: "Deming He" |
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| Title: Re: Blocking functions |
20 Dec 2003 09:04:55 PM |
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Koo <iostream_h@hotmail.com> wrote in message
news:32c6afe6.0312200234.26bb8868@posting.google.com...
How do you create your own blocking function?
Koo
Here's the best
void blocking()
{
char ch;
cin>>ch;
}
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| User: "Koo" |
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| Title: Re: Blocking functions |
21 Dec 2003 04:22:07 AM |
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Well, all of you examples work but i need something that doesn't use
99% of my cup time. I need something that stop the program and wait
for something to happen. And it needs to be fast!
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| User: "Jeff Schwab" |
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| Title: Re: Blocking functions |
21 Dec 2003 10:12:59 AM |
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Koo wrote:
Well, all of you examples work but i need something that doesn't use
99% of my cup time. I need something that stop the program and wait
for something to happen. And it needs to be fast!
Deming's suggestion doesn't use 99% of your CPU time:
void blocking()
{
char ch;
cin>>ch;
}
If you happen to be blocking to wait for input, this is probably the way
to go. If you're blocking for something else, you probably need a
system call. In that case, check in a newsgroup specific to your
platform, and they probably will be able to help you right away.
-Jeff
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| User: "Anders Hybertz" |
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| Title: Re: Blocking functions |
21 Dec 2003 05:00:48 AM |
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Koo wrote:
Well, all of you examples work but i need something that doesn't use
99% of my cup time. I need something that stop the program and wait
for something to happen. And it needs to be fast!
Have a look at www.boost.org and the condition class in the threading
library. It's a non-busy-wait blocking pattern that works very well.
If you are on Windows there are things like WaitForSingleObject that you
could use directly, but that is not platform portable - so I recommend
boost http://www.boost.org/libs/thread/doc/condition.html.
o<|:) /Anders
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| User: "Andy" |
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| Title: Re: Blocking functions |
21 Dec 2003 11:39:20 AM |
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Anders Hybertz <anders@hybertz.dk> wrote in message news:<A3fFb.63023$jf4.3718309@news000.worldonline.dk>...
Koo wrote:
Well, all of you examples work but i need something that doesn't use
99% of my cup time. I need something that stop the program and wait
for something to happen. And it needs to be fast!
Have a look at www.boost.org and the condition class in the threading
library. It's a non-busy-wait blocking pattern that works very well.
That was a useful tip. Not as clever as while(1), for(;;) and cin>>ch; though.
If you are on Windows there are things like WaitForSingleObject that you
could use directly, but that is not platform portable - so I recommend
boost http://www.boost.org/libs/thread/doc/condition.html.
o<|:) /Anders
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| User: "Jeff Schwab" |
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| Title: Re: Blocking functions |
20 Dec 2003 08:42:57 AM |
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Koo wrote:
How do you create your own blocking function?
That's a system call, not part of the language.
The function often looks like this:
#include <unistd.h>
unsigned int sleep(unsigned int seconds);
-Jeff
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| User: "Jack Klein" |
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| Title: Re: Blocking functions |
20 Dec 2003 12:00:02 PM |
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On Sat, 20 Dec 2003 09:42:57 -0500, Jeff Schwab <jeffplus@comcast.net>
wrote in comp.lang.c++:
Koo wrote:
How do you create your own blocking function?
That's a system call, not part of the language.
The function often looks like this:
#include <unistd.h>
unsigned int sleep(unsigned int seconds);
-Jeff
Nonsense, you can write a blocking function in perfectly standard C++.
void blocking_function(void)
{
while(1);
}
....blocks extremely well.
Unblocking is another issue.
--
Jack Klein
Home: http://JK-Technology.Com
FAQs for
comp.lang.c http://www.eskimo.com/~scs/C-faq/top.html
comp.lang.c++ http://www.parashift.com/c++-faq-lite/
alt.comp.lang.learn.c-c++ ftp://snurse-l.org/pub/acllc-c++/faq
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