Class SizedQueue
In: lib/thread.rb
Parent: Queue

This class represents queues of specified size capacity. The push operation may be blocked if the capacity is full.

See Queue for an example of how a SizedQueue works.

Methods

<<   deq   enq   max   max=   new   num_waiting   pop   push   shift  

Public Class methods

new(max)

Creates a fixed-length queue with a maximum size of max.

[Source]

     # File lib/thread.rb, line 374
374:   def initialize(max)
375:     raise ArgumentError, "queue size must be positive" unless max > 0
376:     @max = max
377:     @queue_wait = []
378:     @queue_wait.taint           # enable tainted comunication
379:     super()
380:   end

Public Instance methods

<<(obj)

Alias for push

deq(*args)

Alias for pop

enq(obj)

Alias for push

max()

Returns the maximum size of the queue.

[Source]

     # File lib/thread.rb, line 385
385:   def max
386:     @max
387:   end
max=(max)

Sets the maximum size of the queue.

[Source]

     # File lib/thread.rb, line 392
392:   def max=(max)
393:     Thread.critical = true
394:     if max <= @max
395:       @max = max
396:       Thread.critical = false
397:     else
398:       diff = max - @max
399:       @max = max
400:       Thread.critical = false
401:       diff.times do
402:         begin
403:           t = @queue_wait.shift
404:           t.run if t
405:         rescue ThreadError
406:           retry
407:         end
408:       end
409:     end
410:     max
411:   end
num_waiting()

Returns the number of threads waiting on the queue.

[Source]

     # File lib/thread.rb, line 473
473:   def num_waiting
474:     @waiting.size + @queue_wait.size
475:   end
pop(*args)

Retrieves data from the queue and runs a waiting thread, if any.

[Source]

     # File lib/thread.rb, line 440
440:   def pop(*args)
441:     retval = super
442:     Thread.critical = true
443:     if @que.length < @max
444:       begin
445:         t = @queue_wait.shift
446:         t.wakeup if t
447:       rescue ThreadError
448:         retry
449:       ensure
450:         Thread.critical = false
451:       end
452:       begin
453:         t.run if t
454:       rescue ThreadError
455:       end
456:     end
457:     retval
458:   end
push(obj)

Pushes obj to the queue. If there is no space left in the queue, waits until space becomes available.

[Source]

     # File lib/thread.rb, line 417
417:   def push(obj)
418:     Thread.critical = true
419:     while @que.length >= @max
420:       @queue_wait.push Thread.current
421:       Thread.stop
422:       Thread.critical = true
423:     end
424:     super
425:   end
shift(*args)

Alias for pop

[Validate]