Timer in C (like in Java)

[Alexander Mahone]

Hello, I need a facility in C, like a set of functions, to manage a
timer: I should be able to initialize it with a certain period of time
(like x msec), start it, and every x msec it should execute a certain
function. In a few words, I need something like the java.util.Timer
class, but for C (of course not a class).
Do you know of any implementation of something like that (if possible
real-time)?
Thanks a lot

[Keith Thompson]

Alexander Mahone <sa************ ******@gmail.co mwrites:

Hello, I need a facility in C, like a set of functions, to manage a
timer: I should be able to initialize it with a certain period of time
(like x msec), start it, and every x msec it should execute a certain
function. In a few words, I need something like the java.util.Timer
class, but for C (of course not a class).
Do you know of any implementation of something like that (if possible
real-time)?

Not in standard C. Try a newsgroup that deals with your operating
system.

--
Keith Thompson (The_Other_Keit h) <ks***@mib.or g>
Nokia
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

[santosh]

Alexander Mahone wrote:

Hello, I need a facility in C, like a set of functions, to manage a
timer: I should be able to initialize it with a certain period of time
(like x msec), start it, and every x msec it should execute a certain
function. In a few words, I need something like the java.util.Timer
class, but for C (of course not a class).
Do you know of any implementation of something like that (if possible
real-time)?
Thanks a lot

Standard C has no facilities for what you want to do. However POSIX
specifies ualarm() and setitimer() for interrupting a process after a
specified period. A signal handler can then call your function.

<http://www.mkssoftware .com/docs/man3/ualarm.3.asp>
<http://www.mkssoftware .com/docs/man3/setitimer.3.asp >

[Walter Roberson]

In article <fu*********@re gistered.motzar ella.org>,
santosh <sa*********@gm ail.comwrote:

>Standard C has no facilities for what you want to do. However POSIX
specifies ualarm() and setitimer() for interrupting a process after a
specified period. A signal handler can then call your function.

Neither function was part of POSIX.1-1990.

ualarm() was added to POSIX as of Issue 4, Version 2, and moved from
X/OPEN UNIX extension to BASE of of issue 5 (which I think was 2002.)
As of issue 6 (2004), ualarm() is marked obsolescent.
http://www.opengroup.org/onlinepubs/...ns/ualarm.html

setitimer() was also added and moved at the same issues as for ualarm(),
but setitimer() is not marked obsolescent.
http://www.opengroup.org/onlinepubs/...getitimer.html

For information about what the -recommended- POSIX timer functions are
and their various trade-offs, a unix programming newsgroup should
be consulted.
--
"Walter exemplified class." -- Paul Tagliabue

[santosh]

Walter Roberson wrote:

In article <fu*********@re gistered.motzar ella.org>,
santosh <sa*********@gm ail.comwrote:

>>Standard C has no facilities for what you want to do. However POSIX
specifies ualarm() and setitimer() for interrupting a process after a
specified period. A signal handler can then call your function.

Neither function was part of POSIX.1-1990.

ualarm() was added to POSIX as of Issue 4, Version 2, and moved from
X/OPEN UNIX extension to BASE of of issue 5 (which I think was 2002.)
As of issue 6 (2004), ualarm() is marked obsolescent.
http://www.opengroup.org/onlinepubs/...ns/ualarm.html

setitimer() was also added and moved at the same issues as for
ualarm(), but setitimer() is not marked obsolescent.
http://www.opengroup.org/onlinepubs/...getitimer.html

For information about what the -recommended- POSIX timer functions are
and their various trade-offs, a unix programming newsgroup should
be consulted.

You're right. Apologies to the OP for mentioning an obsolescent
function.

[Anonymous]

On Wed, 23 Apr 2008 21:58:05 +0530, santosh wrote:

Standard C has no facilities for what you want to do. However POSIX
specifies ualarm() and setitimer() for interrupting a process after a
specified period. A signal handler can then call your function.

Only if you're really careful. Only some functions are safe to call in a
signal handler, or functions called from a signal handler. your system's
'man 7 signal()' should give you a list of safe functions to call from a
signal handler.

A unix newsgroup should give more information.

[jon]

there is a simple timer, but it works on the same process (which means
that the program will stop till the timer is done):

sleep(int amount_of_milli seconds);

in windows programing there are ways to create a separate process to
control the timer:

here is a link to a msdn site:

http://msdn2.microsoft.com/en-us/library/ms632592.aspx

(if it doesn't work, try searching (on the same page) for timers and
windows)

// Set two timers.

SetTimer(hwnd, // handle to main window
IDT_TIMER1, // timer identifier
10000, // 10-second interval
(TIMERPROC) NULL); // no timer callback

SetTimer(hwnd, // handle to main window
IDT_TIMER2, // timer identifier
300000, // five-minute interval
(TIMERPROC) NULL); // no timer callback

[Walter Roberson]

In article <3b************ *************** *******@2g2000h sn.googlegroups .com>,
jon <jm******@hotma il.comwrote:

>there is a simple timer, but it works on the same process (which means
that the program will stop till the timer is done):

>sleep(int amount_of_milli seconds);

sleep() is not part of standard C. It is a common operating system
extension, but the original poster did not specify an OS.
--
"Allegories are in the realm of thoughts, what ruins are in
the realm of things." -- Walter Benjamin

[Keith Thompson]

ro******@ibd.nr c-cnrc.gc.ca (Walter Roberson) writes:

In article <3b************ *************** *******@2g2000h sn.googlegroups .com>,
jon <jm******@hotma il.comwrote:

>>there is a simple timer, but it works on the same process (which means
that the program will stop till the timer is done):

>>sleep(int amount_of_milli seconds);

sleep() is not part of standard C. It is a common operating system
extension, but the original poster did not specify an OS.

Furthermore, it's defined differently on different systems. On POSIX
systems, for example, the argument is a number of seconds.

--
Keith Thompson (The_Other_Keit h) <ks***@mib.or g>
Nokia
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"

[Antoninus Twink]

On 23 Apr 2008 at 22:34, Keith Thompson wrote:

ro******@ibd.nr c-cnrc.gc.ca (Walter Roberson) writes:

>sleep() is not part of standard C. It is a common operating system
extension, but the original poster did not specify an OS.

Furthermore, it's defined differently on different systems. On POSIX
systems, for example, the argument is a number of seconds.

You're right, but there are also usleep and nanosleep, for shorter
intervals.