Class: Loompa

Inherits:
Object
  • Object
show all
Includes:
DefaultLogger
Defined in:
lib/loompa.rb

Defined Under Namespace

Classes: Child, Children

Constant Summary collapse

@@children =

class variable holding all the children

Children.new

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from DefaultLogger

debug, error, info

Constructor Details

#initialize(forks_to_run, log_method = DefaultLogger) ⇒ Loompa

Returns a new instance of Loompa.



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# File 'lib/loompa.rb', line 122

def initialize(forks_to_run, log_method = DefaultLogger)
  @min_forks = 1
  @max_forks = forks_to_run
  Loompa.logger = log_method
end

Instance Attribute Details

#child_count ⇒ Object (readonly)

Returns the value of attribute child_count.



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# File 'lib/loompa.rb', line 22

def child_count
  @child_count
end

#max_forks=(value) ⇒ Object (writeonly)

Sets the attribute max_forks

Parameters:

  • value —

    the value to set the attribute max_forks to.



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# File 'lib/loompa.rb', line 108

def max_forks=(value)
  @max_forks = value
end

#on_child_exit(&block) ⇒ Object

A block to be executed upon exiting a child process.

block

block The block that will be executed upon termination of a child process



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# File 'lib/loompa.rb', line 145

def on_child_exit(&block)
  if block == nil then
    raise "block required"
  end
  @on_child_exit = block
end

#on_child_start(&block) ⇒ Object

A block to be executed just before calling the block a child will be executing

block

block The block that will be executed



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# File 'lib/loompa.rb', line 135

def on_child_start(&block)
  if block == nil then
    raise "block required"
  end
  @on_child_start = block
end

Class Method Details

.logger ⇒ Object 



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# File 'lib/loompa.rb', line 113

def logger
  @logger
end

.logger=(log_meth) ⇒ Object 



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# File 'lib/loompa.rb', line 117

def logger=(log_meth)
  @logger = log_meth
end

Instance Method Details

#interrupt ⇒ Object

Sends the TERM signal to all child processes via their pids



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# File 'lib/loompa.rb', line 211

def interrupt()
  Process.kill "TERM", *(@@children.pids) rescue nil
end

#start(&block) ⇒ Object

Starts the child processes, the number of which is determined by the @max_forks variable

block

&block The block that will be executed by the child processes



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# File 'lib/loompa.rb', line 155

def start(&block)
  if block == nil then
    raise "block required"
  end
  (@min_forks - @@children.size).times do
    make_child block
  end
  @flag = :in_loop
  while @flag == :in_loop do
    log = false
    r, = IO.select(@@children.fds, nil, nil, 1)
    if r then
      log = true
      r.each do |f|
        c = @@children.by_fd f
        c.event f.gets
      end
    end
    as = @@children.active.size
    @@children.cleanup if @@children.size > as
    break if @flag != :in_loop
    n = 0
    if as < @min_forks then
      n = @min_forks - as
    else
      if @@children.idle.size <= 2 then
        n = 2
      end
    end
    if as + n > @max_forks then
      n = @max_forks - as
    end
    #Loompa.logger.debug "p: max:#{@max_forks}, min:#{@min_forks}, cur:#{as}, idle:#{@@children.idle.size}: new:#{n}" if n > 0 or log
    n.times do
    	make_child block
    end
  end
  @flag = :out_of_loop
  terminate
end

#stop ⇒ Object

sets the @flag to :exit_loop, essentially stopping the parent and child processes since the loop will die and all children will receive the close() call



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# File 'lib/loompa.rb', line 198

def stop()
  @flag = :exit_loop
end

#terminate ⇒ Object

Calls the close method on each child which sets its status to :closed



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# File 'lib/loompa.rb', line 203

def terminate()
  raise "Cannot terminate while still in the loop" if @flag == :in_loop
  @@children.each do |c|
    c.close
  end
end