[英]How to gracefully shutdown a thread in Ruby
I have been experimenting multi-threading concept in Ruby for the past a week.过去一周我一直在 Ruby 中试验多线程概念。
For practising, I am designing a file downloader that makes parallel requests for a collection of URLs.为了练习,我正在设计一个文件下载器,它对一组 URL 发出并行请求。 Currently I need to safely shutdown threads when interrupt signal is triggered.
目前我需要在触发中断信号时安全地关闭线程。 I have read the theory of multi-threading and catching a signal at runtime.
我已经阅读了多线程和在运行时捕获信号的理论。 Yet despite the whole those theoretical knowledge, I still don't have any idea about how to use them in practice.
然而,尽管有这些理论知识,我仍然不知道如何在实践中使用它们。
I am leaving my proof of concept work below, anyhow.无论如何,我将把我的概念验证工作留在下面。
class MultiThread
attr_reader :limit, :threads, :queue
def initialize(limit)
@limit = limit
@threads = []
@queue = Queue.new
end
def add(*args, &block)
queue << [block, args]
end
def invoke
1.upto(limit).each { threads << spawn_thread }
threads.each(&:join)
end
private
def spawn_thread
Thread.new do
Thread.handle_interrupt(RuntimeError => :on_blocking) do
# Nothing to do
end
until queue.empty?
block, args = queue.pop
block&.call(*args)
end
end
end
end
urls = %w[https://example.com]
thread = MultiThread.new(2)
urls.each do |url|
thread.add do
puts "Downloading #{url}..."
sleep 1
end
end
thread.invoke
Yeah, the docs for handle_interrupt
are confusing.是的,
handle_interrupt
的文档令人困惑。 Try this, which I based on the connection_pool
gem used by eg puma
.试试这个,我基于例如
puma
使用的connection_pool
gem。
$stdout.sync = true
threads = 3.times.map { |i|
Thread.new {
Thread.handle_interrupt(Exception => :never) do
begin
Thread.handle_interrupt(Exception => :immediate) do
puts "Thread #{i} doing work"
sleep 1000
end
ensure
puts "Thread #{i} cleaning up"
end
end
}
}
Signal.trap("INT") {
puts 'Exiting gracefully'
threads.each { |t|
puts 'killing thread'
t.kill
}
exit
}
threads.each { |t| t.join }
Output: Output:
Thread 1 doing work
Thread 2 doing work
Thread 0 doing work
^CExiting gracefully
killing thread
killing thread
killing thread
Thread 0 cleaning up
Thread 1 cleaning up
Thread 2 cleaning up
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.