Blocking functions

[Koo]

How do you create your own blocking function?

Koo

 

[Jeff Schwab]

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

 

[Jack Klein]

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
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[Mike Wahler]

How do you create your own blocking function?

Here, use mine.

void block()
{
for(;
}

-Mike

 

[EventHelix.com]

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

 

[Deming He]

How do you create your own blocking function?

Koo

Here's the best

void blocking()
{
char ch;
cin>>ch;
}

 

[Koo]

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!

 

[Anders Hybertz]

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

 

[Jeff Schwab]

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

 

[Andy]

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.