#795: macirb: GCD inconsistently copies local variables inside blocks ----------------------------------------+----------------------------------- Reporter: ernest.prabhakar@… | Owner: eloy.de.enige@… Type: defect | Status: new Priority: critical | Milestone: Component: MacRuby | Keywords: ----------------------------------------+----------------------------------- Description changed by martinlagardette@…: Old description:

The expectation is that Ruby blocks will have their local variables copied before being passed to GCD, to avoid errors from accessing them after they are destroyed.

However, that does not seem to always happen. For example:

$ macruby -e 'i=0; Dispatch::Queue.new("i").sync {i = 42}; puts i'

returns '0' as expected. However, this does not:

$ macirb irb(main):001:0> i=0; Dispatch::Queue.new("i").sync {i = 42}; puts i 42 => nil

It appears to be copied properly in the block_spec.rb test:

it "should create const copies of dynamic (local) variables" do i = 42 @q.sync {i = 1} i.should == 42 end

But not in the README.rdoc for the dispatch module (aka dispatch_methods.rb sample):

n = 0 job = Dispatch::Job.new { n = 21 } job.join puts "n (after): #{n} => 0?!?" # [returns 21, not 0]

Any suggestions?

New description: The expectation is that Ruby blocks will have their local variables copied before being passed to GCD, to avoid errors from accessing them after they are destroyed. However, that does not seem to always happen. For example: {{{ $ macruby -e 'i=0; Dispatch::Queue.new("i").sync {i = 42}; puts i' }}} returns '0' as expected. However, this does not: {{{ $ macirb irb(main):001:0> i=0; Dispatch::Queue.new("i").sync {i = 42}; puts i 42 => nil }}} It appears to be copied properly in the block_spec.rb test: {{{ #!ruby it "should create const copies of dynamic (local) variables" do i = 42 @q.sync {i = 1} i.should == 42 end }}} But not in the README.rdoc for the dispatch module (aka dispatch_methods.rb sample): {{{ #!ruby n = 0 job = Dispatch::Job.new { n = 21 } job.join puts "n (after): #{n} => 0?!?" # [returns 21, not 0] }}} Any suggestions? -- -- Ticket URL: <http://www.macruby.org/trac/ticket/795#comment:3> MacRuby <http://macruby.org/>