Module: EM::ProcessBuffer

Defined in:
lib/eventmachine/process_buffer.rb,
lib/eventmachine/process_buffer/version.rb,
lib/eventmachine/process_buffer/watcher.rb

Defined Under Namespace

Classes: Watcher

Constant Summary collapse

BIN = 
File.expand_path File.join(__FILE__, '../../../bin')
VERSION = 
"0.0.2"

Class Method Summary collapse

Class Method Details

.attach_to_process(pid, pipe_directory, working_directory, pid_file, command, handler, *args) {|watcher| ... } ⇒ Object

Yields:

  • (watcher) 


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# File 'lib/eventmachine/process_buffer.rb', line 56

def self.attach_to_process pid, pipe_directory, working_directory, pid_file, command, handler, *args
  c = Class.new(EM::ProcessBuffer::Watcher) { include handler }
  watcher = c.new pid_file, pipe_directory, working_directory, *args
  watcher.attach_to_process
  watcher.process_reattached

  yield watcher if block_given?
end

.spawn_detached(cmd, environment = {}) ⇒ Object 



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# File 'lib/eventmachine/process_buffer.rb', line 13

def self.spawn_detached cmd, environment = {}
  begin
    pid, stdin, stdout, stderr = POSIX::Spawn::popen4(environment, cmd)
    Process.detach pid
    return pid, stdin, stdout, stderr
  rescue Errno::EAGAIN # Resource temporarily unavailable
    retry
  end
end

.start_process(pipe_directory, working_directory, pid_file, command, environment, handler, *args, &block) ⇒ Object 



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# File 'lib/eventmachine/process_buffer.rb', line 23

def self.start_process pipe_directory, working_directory, pid_file, command, environment, handler, *args, &block
  buffer_command = %Q{#{BIN}/buffer-process -d #{pipe_directory} -C #{working_directory} -p #{pid_file} "#{command}"}
  buffer_pid, stdin, stdout, stderr = spawn_detached buffer_command, environment
  Process.detach buffer_pid

  wait = EM.add_periodic_timer(0.5) do
    begin
      if Process.waitpid(buffer_pid, Process::WNOHANG)
        stdin.close
        stdout.gets
        wait.cancel

        puts "process exited pid=#{buffer_pid}"

      elsif File.exist?(pid_file)
        stdin.close
        stdout.gets
        wait.cancel

        c = Class.new(EM::ProcessBuffer::Watcher) { include handler }
        watcher = c.new pid_file, pipe_directory, working_directory, *args
        
        watcher.process_started
        watcher.attach_to_process
        
        block.call watcher if block_given?
      end
    rescue Errno::ECHILD
      # waiting...
    end
  end
end