Ruby 线程 class 练习

Question

我正在做一些练习以了解 Ruby 上线程的使用。似乎有些概念我没有遇到我正在尝试做的 class 问题。

在一个市场上，一位农民收获了一种产品并将其放在一个展位上。一名员工拿起产品并将其带到客户的柜台。使两个Ruby线程从参展商处放入和取出产品。

这是我的解决方案，但它不起作用：

require 'thread'

mutex = Mutex.new
cv = ConditionVariable.new

orchard = ["Letuce", "Tomato", "Potato"]
exhibitor = []
counter = []

farmer = Thread.new do
    mutex.synchronize do
        puts "Harvesting..."

        product = huerta.pop()

        puts "Placing the product in an exhibitor..."

        exhibitor.push(product)

        cv.signal
    end
end

employee = Thread.new do
    mutex.synchronize do
        cv.wait(mutex)

        puts "Taking product from exhibitor..."

        product = exhibitor.pop()

        puts "Placing product in the counter..."

        counter.push(product)
    end
end

employee.join
farmer.join

代码背后的想法是，两个线程运行同时，当 farmer 线程结束时发送一个信号，该信号被员工线程截获，等待它做这件事。

我得到以下输出：

Harvesting...
Placing the product in an exhibitor...
Traceback (most recent call last):
        1: from pruebahilos.rb:38:in `<main>'
pruebahilos.rb:38:in `join': No live threads left. Deadlock? (fatal)
2 threads, 2 sleeps current:0x0000557b0cf8ca50 main thread:0x0000557b0ce98050
* #<Thread:0x0000557b0cec6d78 sleep_forever>
   rb_thread_t:0x0000557b0ce98050 native:0x00007fadd7b13ec0 int:0
   pruebahilos.rb:38:in `join'
   pruebahilos.rb:38:in `<main>'
* #<Thread:0x0000557b0d0b5850 pruebahilos.rb:24 sleep_forever>
   rb_thread_t:0x0000557b0cf8ca50 native:0x00007fadd4324700 int:0
    depended by: tb_thread_id:0x0000557b0ce98050
   pruebahilos.rb:26:in `sleep'
   pruebahilos.rb:26:in `wait'
   pruebahilos.rb:26:in `block (2 levels) in <main>'
   pruebahilos.rb:25:in `synchronize'
   pruebahilos.rb:25:in `block in <main>'

Answer 1

发生错误是因为当您创建员工线程并对其调用 join 时，农民的线程可能已经完成其工作并退出（这就是“没有活动线程”错误试图告诉我们的）。

尝试更改创建线程的顺序（在农民线程之前创建员工线程）- 这样应该可以。

Ruby 线程 class 练习

Ruby threads class exercise

ruby

multithreading