Don't wait for Exception in threads

[Emil Sandin]

I have two threads running in parallell, like this:

####################

t1=Thread.new{
50.times{
p "thread one"
sleep 0.1
}
}

t2=Thread.new{
p "thread two"
raise "error in thread two"
}

t1.join
t2.join

#################
The output is:
"thread one"
"thread two"
"thread one"
... 48 times more "thread one"
"thread one"
testscript.rb:15: error in thread two (RuntimeError)
from testscript.rb:19:in `join'
from testscript.rb:19

The program waits for the first thread to complete before telling me
that the second one raised an exception.
I don't want to wait until the first thread finishes to see the
exception, I want to see it right away.
How can I do that?

Regards
Emil

 

[James Gray]

I have two threads running in parallell, like this:

####################

t1=Thread.new{
50.times{
p "thread one"
sleep 0.1
}
}

t2=Thread.new{
p "thread two"
raise "error in thread two"
}

t1.join
t2.join

#################
The output is:
"thread one"
"thread two"
"thread one"
... 48 times more "thread one"
"thread one"
testscript.rb:15: error in thread two (RuntimeError)
from testscript.rb:19:in `join'
from testscript.rb:19

The program waits for the first thread to complete before telling me
that the second one raised an exception.
I don't want to wait until the first thread finishes to see the
exception, I want to see it right away.
How can I do that?

Add this line early in your program:

Thread.abort_on_exception = true

Hope that helps.

James Edward Gray II

 

[akl]

Hi Emil,

I have two threads running in parallell, like this:

####################

t1=Thread.new{
50.times{
p "thread one"
sleep 0.1
}
}

t2=Thread.new{
p "thread two"
raise "error in thread two"
}

t1.join
t2.join

#################
The output is:
"thread one"
"thread two"
"thread one"
... 48 times more "thread one"
"thread one"
testscript.rb:15: error in thread two (RuntimeError)
from testscript.rb:19:in `join'
from testscript.rb:19

The program waits for the first thread to complete before telling me
that the second one raised an exception.
I don't want to wait until the first thread finishes to see the
exception, I want to see it right away.
How can I do that?

You can do something like:

Thread.abort_on_exception = true
t = []
t << Thread.new {
50.times{
p "thread one"
sleep 0.1
}
}
t << Thread.new {
p "thread two"
raise "error in thread two"
}
t.each {|t| t.join }

I dont have tested the example, but this way you should see the Exception in the
Moment it occurs

Andi

 

[Emil Sandin]

Add this line early in your program:

Thread.abort_on_exception = true

Hope that helps.

James Edward Gray II

Thank you, that's exactly what I am looking for.