Class: R10K::Util::Subprocess::Runner::POSIX Private

Inherits:
R10K::Util::Subprocess::Runner show all
Defined in:
lib/r10k/util/subprocess/runner/posix.rb

Overview

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

Implement a POSIX command runner by using fork/exec.

This implementation is optimized to run commands in the background, and has a few noteworthy implementation details.

First off, when the child process is forked, it calls setsid() to detach from the controlling TTY. This has two main ramifications: sending signals will never be send to the forked process, and the forked process does not have access to stdin.

Instance Attribute Summary

Attributes inherited from R10K::Util::Subprocess::Runner

#cwd, #result

Instance Method Summary collapse

Constructor Details

#initialize(argv) ⇒ POSIX

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.

Returns a new instance of POSIX.



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# File 'lib/r10k/util/subprocess/runner/posix.rb', line 18

def initialize(argv)
  @argv = argv
  mkpipes
end

Instance Method Details

#run ⇒ 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. 



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# File 'lib/r10k/util/subprocess/runner/posix.rb', line 23

def run
  # Create a pipe so that the parent can verify that the child process
  # successfully executed. The pipe will be closed on a successful exec(),
  # and will contain an error message on failure.
  exec_r, exec_w = pipe

  @stdout_pump = R10K::Util::Subprocess::Runner::Pump.new(@stdout_r)
  @stderr_pump = R10K::Util::Subprocess::Runner::Pump.new(@stderr_r)
  pid = fork do
    exec_r.close
    execute_child(exec_w)
  end

  exec_w.close
  @stdout_pump.start
  @stderr_pump.start

  execute_parent(exec_r, pid)

  @result
end