一个问题是您需要使用Process.wait
来等待您的分叉进程完成。另一个是你不能通过变量进行进程间通信。要看到这个:
@one = nil
@two = nil
@hash = {}
pidA = fork do
sleep 1
@one = 1
@hash[:one] = 1
p [:one, @one, :hash, @hash] #=> [ :one, 1, :hash, { :one => 1 } ]
end
pidB = fork do
sleep 2
@two = 2
@hash[:two] = 2
p [:two, @two, :hash, @hash] #=> [ :two, 2, :hash, { :two => 2 } ]
end
Process.wait(pidB)
Process.wait(pidA)
p [:one, @one, :two, @two, :hash, @hash] #=> [ :one, nil, :two, nil, :hash, {} ]
进行进程间通信的一种方法是使用管道 ( IO::pipe
)。在你叉之前打开它,然后让叉子的每一侧关闭管道的一端。
来自ri IO::pipe
:
rd, wr = IO.pipe
if fork
wr.close
puts "Parent got: <#{rd.read}>"
rd.close
Process.wait
else
rd.close
puts "Sending message to parent"
wr.write "Hi Dad"
wr.close
end
_produces:_
Sending message to parent
Parent got: <Hi Dad>
如果要共享变量,请使用线程:
@one = nil
@two = nil
@hash = {}
threadA = Thread.fork do
sleep 1
@one = 1
@hash[:one] = 1
p [:one, @one, :hash, @hash] #=> [ :one, 1, :hash, { :one => 1 } ] # (usually)
end
threadB = Thread.fork do
sleep 2
@two = 2
@hash[:two] = 2
p [:two, @two, :hash, @hash] #=> [ :two, 2, :hash, { :one => 1, :two => 2 } ] # (usually)
end
threadA.join
threadB.join
p [:one, @one, :two, @two, :hash, @hash] #=> [ :one, 1, :two, 2, :hash, { :one => 1, :two => 2 } ]
但是,我不确定当您受到 IO 限制时,线程是否会给您带来任何好处。