Class: ChildProcess::Server

Inherits:
Object
  • Object
show all
Defined in:
lib/childprocess/server.rb

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Server

Returns a new instance of Server.



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# File 'lib/childprocess/server.rb', line 28

def initialize
  @processes = {}
  @mutex = Mutex.new
end

Class Method Details

.connect(uri) ⇒ DrbObject<Server>

Connect to existing DRb service.

Parameters:

  • uri (String) —

    drb path

Returns:

  • (DrbObject<Server>) —

    remote server



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# File 'lib/childprocess/server.rb', line 12

def self.connect(uri)
  DRb.start_service
  DRbObject.new_with_uri(uri)
end

Instance Method Details

#alive?(pid) ⇒ Bool

Check whether a process managed by this server is alive.

Parameters:

  • pid (Integer) —

    process id

Returns:

  • (Bool) —

    whether that process is alive, nil if that process is not managed by this server



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# File 'lib/childprocess/server.rb', line 86

def alive?(pid)
  access_processes do |processes|
    processes[pid] && processes[pid].alive?
  end
end

#clean_up ⇒ Object

Clean up exited processes.



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# File 'lib/childprocess/server.rb', line 102

def clean_up
  access_processes do |processes|
    processes.values.select(&:exited?).each do |process|
      process.io.stdout.path.unlink rescue nil
    end
    processes.delete_if { |_, process| process.exited? }
    # Do not leak @processes outside
    # We are using dRuby, keep input/output objects simple
    nil
  end
end

#launch(*commands) ⇒ Integer

Launch a process in background.

Parameters:

  • commands (Array<String>) —

    commands

Returns:

  • (Integer) —

    pid



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# File 'lib/childprocess/server.rb', line 37

def launch(*commands)
  output = Tempfile.new('cps-out')
  output.sync = true

  process = ChildProcess.build(*commands)
  process.io.stdout = process.io.stderr = output
  process.duplex = true
  process.start

  pid = process.pid
  access_processes do |processes|
    processes[pid] = process
  end
  pid
end

#list_pids ⇒ Array<Integer>

List process ids managed by this server.

Returns:

  • (Array<Integer>) —

    process ids



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# File 'lib/childprocess/server.rb', line 75

def list_pids
  access_processes do |processes|
    processes.keys
  end
end

#read_output(pid) ⇒ String

Read output, will not block.

Parameters:

  • pid (Integer) —

    process id

Returns:

  • (String) —

    output so far, nil on error



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# File 'lib/childprocess/server.rb', line 57

def read_output(pid)
  access_processes do |processes|
    File.read(processes[pid].io.stdout.path) rescue nil 
  end
end

#start_service(uri, wait = true) ⇒ DRb::DRbServer

Start DRb service.

Parameters:

  • wait (Bool) (defaults to: true) —

    whether to block and wait for drb service to end

  • uri (String) —

    drb path

Returns:

  • (DRb::DRbServer) 


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# File 'lib/childprocess/server.rb', line 22

def start_service(uri, wait = true)
  server = DRb.start_service(uri, self)
  DRb.thread.join if wait
  server
end

#stop(pid) ⇒ Object

Stop a process managed by this server.

Parameters:

  • pid (Integer) —

    process id



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# File 'lib/childprocess/server.rb', line 95

def stop(pid)
  access_processes do |processes|
    processes[pid] && processes[pid].stop
  end
end

#write_input(pid, content) ⇒ Object

Write to input.

Parameters:

  • pid (Integer) —

    process id



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# File 'lib/childprocess/server.rb', line 66

def write_input(pid, content)
  access_processes do |processes|
    processes[pid] && processes[pid].io.stdin.write(content) rescue nil
  end
end