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require File.expand_path('../helper', __FILE__)
require 'rake/thread_pool'
class TestRakeTestThreadPool < Rake::TestCase
include Rake
def test_pool_executes_in_current_thread_for_zero_threads
pool = ThreadPool.new(0)
f = pool.future { Thread.current }
pool.join
assert_equal Thread.current, f.value
end
def test_pool_executes_in_other_thread_for_pool_of_size_one
pool = ThreadPool.new(1)
f = pool.future { Thread.current }
pool.join
refute_equal Thread.current, f.value
end
def test_pool_executes_in_two_other_threads_for_pool_of_size_two
pool = ThreadPool.new(2)
threads = 2.times.map {
pool.future {
sleep 0.1
Thread.current
}
}.each { |f|
f.value
}
refute_equal threads[0], threads[1]
refute_equal Thread.current, threads[0]
refute_equal Thread.current, threads[1]
ensure
pool.join
end
def test_pool_creates_the_correct_number_of_threads
pool = ThreadPool.new(2)
threads = Set.new
t_mutex = Mutex.new
10.times.each do
pool.future do
sleep 0.02
t_mutex.synchronize { threads << Thread.current }
end
end
pool.join
assert_equal 2, threads.count
end
def test_pool_future_does_not_duplicate_arguments
pool = ThreadPool.new(2)
obj = Object.new
captured = nil
pool.future(obj) { |var| captured = var }
pool.join
assert_equal obj, captured
end
def test_pool_join_empties_queue
pool = ThreadPool.new(2)
repeat = 25
repeat.times {
pool.future do
repeat.times {
pool.future do
repeat.times {
pool.future do end
}
end
}
end
}
pool.join
assert_equal(
true,
pool.__send__(:__queue__).empty?,
"queue should be empty")
end
CustomError = Class.new(StandardError)
# test that throwing an exception way down in the blocks propagates
# to the top
def test_exceptions
pool = ThreadPool.new(10)
deep_exception_block = lambda do |count|
raise CustomError if count < 1
pool.future(count - 1, &deep_exception_block).value
end
assert_raises(CustomError) do
pool.future(2, &deep_exception_block).value
end
ensure
pool.join
end
def test_pool_prevents_deadlock
pool = ThreadPool.new(5)
common_dependency_a = pool.future { sleep 0.2 }
futures_a = 10.times.map {
pool.future {
common_dependency_a.value
sleep(rand() * 0.01)
}
}
common_dependency_b = pool.future { futures_a.each { |f| f.value } }
futures_b = 10.times.map {
pool.future {
common_dependency_b.value
sleep(rand() * 0.01)
}
}
futures_b.each { |f| f.value }
pool.join
end
def test_pool_reports_correct_results
pool = ThreadPool.new(7)
a = 18
b = 5
c = 3
result = a.times.map do
pool.future do
b.times.map do
pool.future { sleep rand * 0.001; c }
end.reduce(0) { |m, f| m + f.value }
end
end.reduce(0) { |m, f| m + f.value }
assert_equal a * b * c, result
pool.join
end
end
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