SizedQueue

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.

Public Class Methods

new(max) click to toggle source

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

 
 # File thread.rb, line 251
def initialize(max)
 raise ArgumentError, "queue size must be positive" unless max > 0
 @max = max
 @queue_wait = []
 @queue_wait.taint # enable tainted comunication
 super()
end

Public Instance Methods

<<(obj) click to toggle source

Alias of push

Alias for: push

clear() click to toggle source

Removes all objects from the queue and wakes waiting threads, if any.

 
 # File thread.rb, line 362
def clear
 @mutex.synchronize do
 @que.clear
 begin
 until @queue_wait.empty?
 @queue_wait.shift.wakeup
 end
 rescue ThreadError
 retry
 end
 end
end

deq(*args) click to toggle source

Alias of pop

Alias for: pop

enq(obj) click to toggle source

Alias of push

Alias for: push

max() click to toggle source

Returns the maximum size of the queue.

 
 # File thread.rb, line 262
def max
 @max
end

max=(max) click to toggle source

Sets the maximum size of the queue.

 
 # File thread.rb, line 269
def max=(max)
 diff = nil
 @mutex.synchronize {
 if max <= @max
 @max = max
 else
 diff = max - @max
 @max = max
 end
 }
 if diff
 diff.times do
 begin
 t = @queue_wait.shift
 t.run if t
 rescue ThreadError
 retry
 end
 end
 end
 max
end

num_waiting() click to toggle source

Returns the number of threads waiting on the queue.

 
 # File thread.rb, line 355
def num_waiting
 @waiting.size + @queue_wait.size
end

pop(*args) click to toggle source

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

 
 # File thread.rb, line 327
def pop(*args)
 retval = super
 @mutex.synchronize {
 if @que.length < @max
 begin
 t = @queue_wait.shift
 t.wakeup if t
 rescue ThreadError
 retry
 end
 end
 }
 retval
end

Also aliased as: shift, deq

push(obj) click to toggle source

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

 
 # File thread.rb, line 296
def push(obj)
 @mutex.synchronize{
 while true
 break if @que.length < @max
 @queue_wait.push Thread.current
 @mutex.sleep
 end
 @que.push obj
 begin
 t = @waiting.shift
 t.wakeup if t
 rescue ThreadError
 retry
 end
 }
end

Also aliased as: <<, enq

shift(*args) click to toggle source

Alias of pop

Alias for: pop