ThreadsWait

This class watches for termination of multiple threads. Basic functionality (wait until specified threads have terminated) can be accessed through the class method ::all_waits. Finer control can be gained using instance methods.

Example:

ThreadsWait.all_waits(thr1, thr2, ...) do |t|
  STDERR.puts "Thread #{t} has terminated."
end

th = ThreadsWait.new(thread1,...)
th.next_wait # next one to be done

Attributes

threads[R]

Returns the array of threads that have not terminated yet.

Public Class Methods

all_waits(*threads)

Waits until all specified threads have terminated. If a block is provided, it is executed for each thread as they terminate.

 
               # File thwait.rb, line 37
def ThreadsWait.all_waits(*threads) # :yield: thread
  tw = ThreadsWait.new(*threads)
  if block_given?
    tw.all_waits do |th|
      yield th
    end
  else
    tw.all_waits
  end
end

new(*threads)

Creates a ThreadsWait object, specifying the threads to wait on. Non-blocking.

 
               # File thwait.rb, line 52
def initialize(*threads)
  @threads = []
  @wait_queue = Queue.new
  join_nowait(*threads) unless threads.empty?
end

Public Instance Methods

all_waits()

Waits until all of the specified threads are terminated. If a block is supplied for the method, it is executed for each thread termination.

Raises exceptions in the same manner as next_wait.

 
               # File thwait.rb, line 125
def all_waits
  until @threads.empty?
    th = next_wait
    yield th if block_given?
  end
end

empty?()

Returns true if there are no threads in the pool still running.

 
               # File thwait.rb, line 64
def empty?
  @threads.empty?
end

finished?()

Returns true if any thread has terminated and is ready to be collected.

 
               # File thwait.rb, line 71
def finished?
  !@wait_queue.empty?
end

join(*threads)

Waits for specified threads to terminate, and returns when one of the threads terminated.

 
               # File thwait.rb, line 79
def join(*threads)
  join_nowait(*threads)
  next_wait
end

join_nowait(*threads)

Specifies the threads that this object will wait for, but does not actually wait.

 
               # File thwait.rb, line 88
def join_nowait(*threads)
  threads.flatten!
  @threads.concat threads
  for th in threads
    Thread.start(th) do |t|
      begin
        t.join
      ensure
        @wait_queue.push t
      end
    end
  end
end

next_wait(nonblock = nil)

Waits until any of the specified threads has terminated, and returns the one that does.

If there is no thread to wait, raises ErrNoWaitingThread. If nonblock is true, and there is no terminated thread, raises ErrNoFinishedThread.

 
               # File thwait.rb, line 109
def next_wait(nonblock = nil)
  ThreadsWait.fail ErrNoWaitingThread if @threads.empty?
  begin
    @threads.delete(th = @wait_queue.pop(nonblock))
    th
  rescue ThreadError
    ThreadsWait.fail ErrNoFinishedThread
  end
end