Class: Autorespawn::Manager

Inherits:
Object
  • Object
show all
Includes:
Hooks, Hooks::InstanceHooks
Defined in:
lib/autorespawn/manager.rb

Overview

Manager of a bunch of autorespawn slaves

Instance Attribute Summary collapse

Hooks collapse

Instance Method Summary collapse

Methods included from Hooks

included

Constructor Details

#initialize(name: nil, parallel_level: 1) ⇒ Manager

Returns a new instance of Manager.



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# File 'lib/autorespawn/manager.rb', line 75

def initialize(name: nil, parallel_level: 1)
    @parallel_level = parallel_level
    @workers   = Array.new
    @name = name
    @seed = ProgramID.for_self
    @tracked_files = Hash.new

    @self_slave = Self.new(name: name)
    @workers << self_slave
    @queued_slaves = Array.new
    @active_slaves = Hash[self_slave.pid => self_slave]
end

Instance Attribute Details

#active_slaves ⇒ Hash<Slave> (readonly)

Returns list of active slaves.

Returns:

  • (Hash<Slave>) —

    list of active slaves



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# File 'lib/autorespawn/manager.rb', line 25

def active_slaves
  @active_slaves
end

#name ⇒ Object (readonly)

Returns an object that is used to identify the manager itself.

Returns:

  • (Object) —

    an object that is used to identify the manager itself



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# File 'lib/autorespawn/manager.rb', line 14

def name
  @name
end

#parallel_level ⇒ Integer

Returns the number of processes allowed to work in parallel.

Returns:

  • (Integer) —

    the number of processes allowed to work in parallel



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# File 'lib/autorespawn/manager.rb', line 20

def parallel_level
  @parallel_level
end

#queued_slaves ⇒ Array<Slave> (readonly)

Returns list of slaves explicitely queued with #queue.

Returns:

  • (Array<Slave>) —

    list of slaves explicitely queued with #queue



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# File 'lib/autorespawn/manager.rb', line 27

def queued_slaves
  @queued_slaves
end

#seed ⇒ ProgramID (readonly)

Returns a seed object that is passed to new slaves to represent the currently known state of file, to avoid unnecessary respawning.

Returns:

  • (ProgramID) —

    a seed object that is passed to new slaves to represent the currently known state of file, to avoid unnecessary respawning

See Also:

  • add_seed_file


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# File 'lib/autorespawn/manager.rb', line 12

def seed
  @seed
end

#self_slave ⇒ Self (readonly)

Returns an object that has the same API than [Slave] to represent the manager’s process itself. It is always included in #workers and #active_slaves.

Returns:

  • (Self) —

    an object that has the same API than [Slave] to represent the manager’s process itself. It is always included in #workers and #active_slaves



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# File 'lib/autorespawn/manager.rb', line 18

def self_slave
  @self_slave
end

#tracked_files ⇒ Hash<Pathname,TrackedFile> (readonly)

Returns the whole set of files that are tracked by this manager’s slaves.

Returns:

  • (Hash<Pathname,TrackedFile>) —

    the whole set of files that are tracked by this manager’s slaves



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# File 'lib/autorespawn/manager.rb', line 30

def tracked_files
  @tracked_files
end

#workers ⇒ Array<Slave> (readonly)

Returns declared worker processes, as a hash from the PID to a Slave object.

Returns:

  • (Array<Slave>) —

    declared worker processes, as a hash from the PID to a Slave object



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# File 'lib/autorespawn/manager.rb', line 23

def workers
  @workers
end

Instance Method Details

#active?(slave) ⇒ Boolean

Tests whether this slave is currently active on self

Returns:

  • (Boolean) 


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# File 'lib/autorespawn/manager.rb', line 117

def active?(slave)
    active_slaves[slave.pid] == slave
end

#add_slave(*cmdline, name: nil, **spawn_options) ⇒ Object

Spawns a worker, i.e. a program that will perform the intended work and report the program state

Parameters:

  • name (Object) (defaults to: nil) —

    an arbitrary object that can be used for reporting / tracking



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# File 'lib/autorespawn/manager.rb', line 126

def add_slave(*cmdline, name: nil, **spawn_options)
    slave = Slave.new(*cmdline, name: name, seed: seed, **spawn_options)
    slave.needed!
    register_slave(slave)
    slave
end

#clear ⇒ Object

Kill and remove all workers from this manager

See Also:



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# File 'lib/autorespawn/manager.rb', line 209

def clear
    kill
    workers.dup.each do |w|
        if w != self_slave
            remove_slave(w)
        end
    end
end

#collect_finished_slaves ⇒ Array<Slave>

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Collect information about the finished slaves

Returns:

  • (Array<Slave>) —

    the slaves that finished



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# File 'lib/autorespawn/manager.rb', line 163

def collect_finished_slaves
    finished_slaves = Array.new
    while finished_child = Process.waitpid2(-1, Process::WNOHANG)
        finished_slaves << process_finished_slave(*finished_child)
    end
    finished_slaves
rescue Errno::ECHILD
    finished_slaves
end

#has_active_slaves? ⇒ Boolean

Tests whether this manager has some slaves that are active

Returns:

  • (Boolean) 


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# File 'lib/autorespawn/manager.rb', line 112

def has_active_slaves?
    active_slaves.size != 1
end

#has_slaves? ⇒ Boolean

Check whether this manager has slaves

Returns:

  • (Boolean) 


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# File 'lib/autorespawn/manager.rb', line 96

def has_slaves?
    # There's always a worker for self
    workers.size != 1
end

#include?(slave) ⇒ Boolean

Tests whether this slave is registered as a worker on self

Returns:

  • (Boolean) 


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# File 'lib/autorespawn/manager.rb', line 107

def include?(slave)
    workers.include?(slave)
end

#kill ⇒ Object

Kill all active slaves

See Also:



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# File 'lib/autorespawn/manager.rb', line 197

def kill
    active_slaves.each_value { |s| s.kill(join: false) }
    while has_active_slaves?
        finished_child = Process.waitpid2(-1)
        process_finished_slave(*finished_child)
    end
rescue Errno::ECHILD
end

#on_slave_finished {|the| ... } ⇒ Object

Hook called when a slave finishes

Yield Parameters:



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# File 'lib/autorespawn/manager.rb', line 64

define_hooks :on_slave_finished

#on_slave_new(&block) {|the| ... } ⇒ Object

Register a callback for when a new slave is added by #add_slave

Parameters:

  • block (#call) —

    the callback

Yield Parameters:

  • the (Slave) —

    new slave



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# File 'lib/autorespawn/manager.rb', line 38

def on_slave_new(&block)
    __on_slave_new(&block)
    workers.each do |w|
        block.call(w)
    end
end

#on_slave_removed {|the| ... } ⇒ Object

Hook called when a slave has been removed from this manager

Yield Parameters:



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# File 'lib/autorespawn/manager.rb', line 71

define_hooks :on_slave_removed

#on_slave_start(&block) {|the| ... } ⇒ Object

Register a callback that should be called when a new slave has been spawned by #poll

Parameters:

  • block (#call) —

    the callback

Yield Parameters:

  • the (Slave) —

    newly started slave



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# File 'lib/autorespawn/manager.rb', line 51

def on_slave_start(&block)
    __on_slave_start(&block)
    active_slaves.each_value do |w|
        block.call(w)
    end
end

#poll(autospawn: true, update_files: true) ⇒ Object

Wait for children to terminate and spawns them when needed



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# File 'lib/autorespawn/manager.rb', line 244

def poll(autospawn: true, update_files: true)
    finished_slaves = collect_finished_slaves
    new_slaves = Array.new

    trigger_slaves_as_necessary

    while active_slaves.size < parallel_level + 1
        if slave = queued_slaves.find { |s| !s.running? }
            queued_slaves.delete(slave)
        elsif autospawn && (slave_i = workers.index { |s| s.needed? })
            slave = workers.delete_at(slave_i)
            @workers = workers[slave_i..-1] + workers[0, slave_i] + [slave]
        end

        if slave
            slave.spawn
            # We manually track the slave's needed flag, just forcefully
            # set it to false at that point
            slave.not_needed!
            run_hook :__on_slave_start, slave
            new_slaves << slave
            active_slaves[slave.pid] = slave
        else
            break
        end
    end
    return new_slaves, finished_slaves
end

#process_finished_slave(pid, status) ⇒ Object 



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# File 'lib/autorespawn/manager.rb', line 173

def process_finished_slave(pid, status)
    return if !(slave = active_slaves.delete(pid))

    if slave.finished(status).empty?
        # Do not register the slave if it is already marked as needed?
        slave.each_tracked_file(with_status: true) do |path, mtime, size|
            tracker = (tracked_files[path] ||= TrackedFile.new(path, mtime: mtime, size: size))
            tracker.slaves << slave
        end
        slave.not_needed!
    end

    slave.subcommands.each do |name, cmdline, spawn_options|
        add_slave(*cmdline, name: name, **spawn_options)
    end
    seed.merge!(slave.program_id)

    run_hook :on_slave_finished, slave
    slave
end

#queue(slave) ⇒ Object

Queue a slave for execution



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# File 'lib/autorespawn/manager.rb', line 154

def queue(slave)
    queued_slaves << slave
end

#register_seed_files(files, search_patch = seed.ruby_load_path, ignore_not_found: true) ⇒ Object

Add files to #seed

(see ProgramID#register_files)



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# File 'lib/autorespawn/manager.rb', line 91

def register_seed_files(files, search_patch = seed.ruby_load_path, ignore_not_found: true)
    seed.register_files(files, search_path, ignore_not_found)
end

#register_slave(slave) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Registers a slave



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# File 'lib/autorespawn/manager.rb', line 147

def register_slave(slave)
    workers << slave
    run_hook :__on_slave_new, slave
    slave
end

#remove_slave(slave) ⇒ Object

Remove a worker from this manager

Raises:

  • (ArgumentError) —

    if the slave is still running



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# File 'lib/autorespawn/manager.rb', line 136

def remove_slave(slave)
    if active?(slave)
        raise ArgumentError, "#{slave} is still running"
    end
    workers.delete(slave)
    run_hook :on_slave_removed, slave
end

#run ⇒ Object 



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# File 'lib/autorespawn/manager.rb', line 218

def run
    while true
        poll
        sleep 1
    end

rescue Interrupt
ensure
    active_slaves.values.each do |slave|
        slave.kill
    end
end

#slave_count ⇒ Object

The number of slaves registered



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# File 'lib/autorespawn/manager.rb', line 102

def slave_count
    workers.size - 1
end

#trigger_slaves_as_necessary ⇒ Object 



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# File 'lib/autorespawn/manager.rb', line 231

def trigger_slaves_as_necessary
    tracked_files.delete_if do |path, tracker|
        tracker.slaves.delete_if(&:needed?)
        if tracker.slaves.empty?
            true
        elsif tracker.update
            tracker.slaves.each(&:needed!)
            true
        end
    end
end