@@ -1,3 +1,5 @@ +0.3.0 +- allow execute to take args, so we can reset the scope 0.2.1 - mutex in case Array#<< and Array#shift aren't atomic 0.2.0 CHANGELOG @@ -6,4 +6,22 @@ Usage: require "thread_pool" pool = ThreadPool.new(threads = 10) pool.execute { puts "I'm writing from a thread" } + pool.join + +It's often useful to make sure that the properties of Ruby's blocks don't bite you. The following code will usually print three nils, because n keeps changing. + + pool = ThreadPool.new(threads = 10) + numbers = [1, 2, 3] + while n = numbers.shift + pool.execute { puts n.inspect } + end + pool.join + +Passing arguments to execute avoids this. i.e.: + + pool = ThreadPool.new(threads = 10) + numbers = [1, 2, 3] + while n = numbers.shift + pool.execute(n) {|local| puts local.inspect } + end pool.join \ No newline at end of file README @@ -7,11 +7,12 @@ class ThreadPool def initialize(queue, mutex) @thread = Thread.new do loop do - mutex.synchronize { @block = queue.shift } - if @block + mutex.synchronize { @tuple = queue.shift } + if @tuple + args, block = @tuple @active = true - @block.call - @block.complete = true + block.call(*args) + block.complete = true else @active = false sleep 0.01 @@ -38,7 +39,7 @@ class ThreadPool end # Runs the block at some time in the near future - def execute(&block) + def execute(*args, &block) init_completable(block) if @queue_limit > 0 @@ -46,13 +47,13 @@ class ThreadPool end @mutex.synchronize do - @queue << block + @queue << [args, block] end end # Runs the block at some time in the near future, and blocks until complete - def synchronous_execute(&block) - execute(&block) + def synchronous_execute(*args, &block) + execute(*args, &block) sleep 0.01 until block.complete? end lib/thread_pool.rb @@ -30,6 +30,31 @@ class TestThreadPool < Test::Unit::TestCase assert_equal n - THREADS, @pool.waiting end + class A + def initialize(i) + @i = i + end + attr_reader :i + end + + def test_context + @foo = [] + @bar = (0...5).to_a + while c = @bar.shift + @pool.execute { @foo << c } + end + @pool.join + assert_equal [nil] * 5, @foo + + @foo = [] + @bar = (0...5).to_a + while c = @bar.shift + @pool.execute(c) {|n| @foo << n } + end + @pool.join + assert_equal (0...5).to_a, @foo + end + def test_queue_limit n = 50 @foo = 0 test/test_thread_pool.rb edc6797387de3355ccac6bcdebbdab4c6b7fe05d Kyle Maxwell kyle@kyle-maxwells-macbook.local http://github.com/fizx/thread_pool/commit/c4a61a495177b212f54d62b5b4d8a842c9ed4d4f c4a61a495177b212f54d62b5b4d8a842c9ed4d4f 2008-09-24T20:59:54-07:00 2008-09-24T20:59:54-07:00 prevent scope gotchas ec8aa4ae3f5ec1126f36e1cd67a5f70e607f4094 Kyle Maxwell kyle@kyle-maxwells-macbook.local