我的第一个问题,但我已经潜伏了很长时间,所以如果我违反任何规则或发布垃圾问题,你将不得不原谅我。
我试图更好地理解线程,我决定测试 MRI,看看它的总体表现如何。
给定以下代码(和输出),为什么线程操作比非线程变体慢得多?
代码
class Benchmarker
def self.go
puts '----------Benchmark Start----------'
start_t = Time.now
yield
end_t = Time.now
puts "Operation Took: #{end_t - start_t} seconds"
puts '----------Benchmark End------------'
end
end
# using mutex
puts 'Benchmark 1 (threaded, mutex):'
Benchmarker.go do
array = []
mutex = Mutex.new
5000.times.map do
Thread.new do
mutex.synchronize do
1000.times do
array << nil
end
end
end
end.each(&:join)
puts array.size
end
# using threads
puts 'Benchmark 2 (threaded, no mutex):'
Benchmarker.go do
array = []
5000.times.map do
Thread.new do
1000.times do
array << nil
end
end
end.each(&:join)
puts array.size
end
# no threads
puts 'Benchmark 3 (no threads):'
Benchmarker.go do
array = []
5000.times.map do
1000.times do
array << nil
end
end
puts array.size
end
输出
Benchmark 1 (threaded, mutex):
----------Benchmark Start----------
5000000
Operation Took: 3.373886 seconds
----------Benchmark End------------
Benchmark 2 (threaded, no mutex):
----------Benchmark Start----------
5000000
Operation Took: 5.040501 seconds
----------Benchmark End------------
Benchmark 3 (no threads):
----------Benchmark Start----------
5000000
Operation Took: 0.454665 seconds
----------Benchmark End------------
提前致谢。