Scheduler and thread

Ruby
1

Hi
I want to make a scheduler like this.

module Timer
def Timer.repeat_every(interval)
Thread.new do
loop do
start_time = Time.now
yield
elapsed = Time.now - start_time
sleep([interval - elapsed, 0].max)
end
end.join
end
end

Timer.repeat_every(5) do
puts Time.now.to_i
end

puts “Doing other stuff…”

But it never prints out “Doing other stuff…”

How can I make it print out like
“Doing other stuff…”
1318284723
1318284728
1318284733

Thanks

2

On 11/10/11 11:20, lover ruby wrote:

     sleep([interval - elapsed, 0].max)

But it never prints out “Doing other stuff…”

How can I make it print out like
“Doing other stuff…”
1318284723
1318284728
1318284733

Thanks
Try this;

module Timer

@timer = nil

def Timer.repeat_every(interval)
@timer = Thread.new do
loop do
start_time = Time.now
yield
elapsed = Time.now - start_time
sleep([interval - elapsed, 0].max)
end
end
end

def Timer.stop
unless @timer.nil?
@timer.kill
@timer.join(1) # don’t hang forever
@timer = nil
end
end

end

Timer.repeat_every(5) do
puts Time.now.to_i
end

puts “Doing other stuff…”
sleep 10
puts “Stopping timer”
Timer.stop

As far as I can tell your execution is hanging on the join which will
never return as the timer thread is in an infinite loop =]

Hope that helps
Sam

3

Sam D. wrote in post #1025958:

On 11/10/11 11:20, lover ruby wrote:

     sleep([interval - elapsed, 0].max)

But it never prints out “Doing other stuff…”

How can I make it print out like
“Doing other stuff…”
1318284723
1318284728
1318284733

Thanks
Try this;

module Timer

@timer = nil

def Timer.repeat_every(interval)
@timer = Thread.new do
loop do
start_time = Time.now
yield
elapsed = Time.now - start_time
sleep([interval - elapsed, 0].max)
end
end
end

def Timer.stop
unless @timer.nil?
@timer.kill
@timer.join(1) # don’t hang forever
@timer = nil
end
end

end

Timer.repeat_every(5) do
puts Time.now.to_i
end

puts “Doing other stuff…”
sleep 10
puts “Stopping timer”
Timer.stop

As far as I can tell your execution is hanging on the join which will
never return as the timer thread is in an infinite loop =]

Hope that helps
Sam

Thanks for help.
The result is
1318313034Doing other stuff…

1318313039

And stop. Even I remove Timer.stop.

I want something like UI.start_timer in Google sketchup. After
UI.start_timer, every code is executable. So the UI.start_timer acts
like a background process.

4

On Tue, Oct 11, 2011 at 8:08 AM, lover ruby [email protected]
wrote:

1318284733
loop do
@timer.kill

Sam
UI.start_timer, every code is executable. So the UI.start_timer acts
like a background process.

Then you must not #join in the method that start the thread as Sam
explained.

Example:

Kind regards

robert

5

On 12/10/11 05:04, lover ruby wrote:

Then you must not #join in the method that start the thread as Sam

1318348633
1318348638
1318348643
1318348633
1318348638
1318348643
…Forever, always print out number every 5 seconds

Can you explain what you mean by “still need sleep 20”?

Sam

6

Robert K. wrote in post #1026082:

On Tue, Oct 11, 2011 at 8:08 AM, lover ruby [email protected]
wrote:

1318284733
loop do
@timer.kill

Sam
UI.start_timer, every code is executable. So the UI.start_timer acts
like a background process.

Then you must not #join in the method that start the thread as Sam
explained.

Example:
Timer example · GitHub

Kind regards

robert

Thanks
I tried you code, but still need sleep 20. what I really want

require ‘timer’
Timer.repeat_every(5) do
puts Time.now.to_i
end

puts “Doing other stuff…”
#sleep 20

The output will be
“Doing other stuff…”
1318348633
1318348638
1318348643
1318348633
1318348638
1318348643
…Forever, always print out number every 5 seconds

7

Sam D. wrote in post #1026126:

On 12/10/11 05:04, lover ruby wrote:

Then you must not #join in the method that start the thread as Sam

1318348633
1318348638
1318348643
1318348633
1318348638
1318348643
…Forever, always print out number every 5 seconds

Can you explain what you mean by “still need sleep 20”?

Sam

Hi Sam
I understand now. The reason I said “still need sleep 20” was:

I had experience with GUI application which is always on. So there was
no need for sleep command.

But now I have a cmd (Windows DOS, xterm) application which terminates
at the last command. The only way to keep program alive is sleep
command. So to keep it alive forever, I change sleep 20 to sleep.

It is really my fault; I did think in GUI world for cmd world.
Thanks for help, Sam. I apply your advanced Timer class in my program.

Ruby lover.

8

On Tue, Oct 11, 2011 at 6:04 PM, lover ruby [email protected]
wrote:

Thanks
The output will be
“Doing other stuff…”
1318348633
1318348638
1318348643
1318348633
1318348638
1318348643
…Forever, always print out number every 5 seconds

Then you better exchange foreground and background task:

Thread.new do
puts “Doing other stuff…”
end

loop do
puts Time.now.to_i
sleep 5
end

Kind regards

robert

9

On 12/10/11 09:24, lover ruby wrote:

at the last command. The only way to keep program alive is sleep
command. So to keep it alive forever, I change sleep 20 to sleep.

It is really my fault; I did think in GUI world for cmd world.
Thanks for help, Sam. I apply your advanced Timer class in my program.

Ruby lover.

Oh, I think I understand now =]

glhf

Sam

10

Thanks Robert. I use your Timer class in my program.