Module: Vagrant::Util::SafeExec

Included in:
SSH
Defined in:
lib/vagrant/util/safe_exec.rb

Overview

This module provies a safe_exec method which is a drop-in replacement for Kernel.exec which addresses a specific issue which manifests on OS X 10.5 (GH-51) and perhaps other operating systems. This issue causes exec to fail if there is more than one system thread. In that case, safe_exec automatically falls back to forking.

Instance Method Summary collapse

Instance Method Details

#safe_exec(command, *args) ⇒ Object 



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# File 'lib/vagrant/util/safe_exec.rb', line 10

def safe_exec(command, *args)
  # Create a list of things to rescue from. Since this is OS
  # specific, we need to do some defined? checks here to make
  # sure they exist.
  rescue_from = []
  rescue_from << Errno::EOPNOTSUPP if defined?(Errno::EOPNOTSUPP)
  rescue_from << Errno::E045 if defined?(Errno::E045)
  rescue_from << SystemCallError

  fork_instead = false
  begin
    pid = nil
    pid = fork if fork_instead
    Kernel.exec(command, *args) if pid.nil?
    Process.wait(pid) if pid
  rescue *rescue_from
    # We retried already, raise the issue and be done
    raise if fork_instead

    # The error manifested itself, retry with a fork.
    fork_instead = true
    retry
  end
end