From: Julian Leviston <julian@...>
Date: 2009-02-17T12:40:40+09:00
Subject: Re: Ruby Threading question Creating 4 threads

That won't ever exit the thread because puts returns nil.

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On 17/02/2009, at 9:10 AM, Louis-Philippe <default@spiralix.org> wrote:

> what if you put your thread body in an infinite loop, something like:
>
> Thread.new do
>  loop do
>    puts "Thread #{c} created"
>     job = nil
>
>     mu.synchronize do
>       job = $jobs.pop
>       puts "Checking for #{job}"
>       #Exit our thread if we have no more jobs to check
>       puts "No more jobs" and Thread.exit if job.nil?
>     end
>
>     t = count_files(job)
>     mu.synchronize { total += t }
>  end
> end
>
> and as you may have noticed, I replaced the 'return' statement  
> inside your
> thread with a 'Thread.exit' method.
> I think it would be the right way to do it...
>
> 2009/2/16 <tristin.colby@gmail.com>
>
>> Newbie Question:
>>
>> I have some code where I create 4 threads that pop elements off an
>> array and process them.  The problem is that each thread only pops  
>> off
>> one element, processes it, then returns; they don't continue to
>> process until the entire array is consumed.
>>
>> <code>
>> $jobs = %w[a b c d e f g]
>> def simulate_cleanup
>>
>> puts "Checking for #{$jobs.length} jobs in /mnt/gen1/focal/temp"
>> threads = []
>>
>> mu = Mutex.new
>> total = 0
>>
>> 1.upto(4) do |c|
>>    threads << Thread.new do
>>     puts "Thread #{c} created"
>>     job = nil
>>
>>     mu.synchronize do
>>       job = $jobs.pop
>>       puts "Checking for #{job}"
>>       #Exit our thread if we have no more jobs to check
>>       puts "No more jobs" and return if job.nil?
>>     end
>>
>>     t = count_files(job)
>>     mu.synchronize { total += t }
>>   end
>> end
>> threads.each { |t| t.join }
>>
>> puts "Reduced by #{total} files"
>> end
>>
>> Example of output:
>> Thread 1 created
>> Thread 2 created
>> Thread 3 created
>> Thread 4 created
>> Checking for a
>> Checking for b
>> Checking for c
>> Checking for d
>>
>>
>>