ruby--ruby/spec/ruby/core/process/wait_spec.rb

require_relative '../../spec_helper'
require_relative 'fixtures/common'

describe "Process.wait" do
  ProcessSpecs.use_system_ruby(self)

  before :all do
    begin
      leaked = Process.waitall
      puts "leaked before wait specs: #{leaked}" unless leaked.empty?
    rescue NotImplementedError
    end
  end

  it "raises an Errno::ECHILD if there are no child processes" do
    lambda { Process.wait }.should raise_error(Errno::ECHILD)
  end

  platform_is_not :windows do
    it "returns its childs pid" do
      pid = Process.spawn(ruby_cmd('exit'))
      Process.wait.should == pid
    end

    it "sets $? to a Process::Status" do
      pid = Process.spawn(ruby_cmd('exit'))
      Process.wait
      $?.should be_kind_of(Process::Status)
      $?.pid.should == pid
    end

    it "waits for any child process if no pid is given" do
      pid = Process.spawn(ruby_cmd('exit'))
      Process.wait.should == pid
      lambda { Process.kill(0, pid) }.should raise_error(Errno::ESRCH)
    end

    it "waits for a specific child if a pid is given" do
      pid1 = Process.spawn(ruby_cmd('exit'))
      pid2 = Process.spawn(ruby_cmd('exit'))
      Process.wait(pid2).should == pid2
      Process.wait(pid1).should == pid1
      lambda { Process.kill(0, pid1) }.should raise_error(Errno::ESRCH)
      lambda { Process.kill(0, pid2) }.should raise_error(Errno::ESRCH)
    end

    it "coerces the pid to an Integer" do
      pid1 = Process.spawn(ruby_cmd('exit'))
      Process.wait(mock_int(pid1)).should == pid1
      lambda { Process.kill(0, pid1) }.should raise_error(Errno::ESRCH)
    end

    # This spec is probably system-dependent.
    it "waits for a child whose process group ID is that of the calling process" do
      pid1 = Process.spawn(ruby_cmd('exit'), pgroup: true)
      pid2 = Process.spawn(ruby_cmd('exit'))

      Process.wait(0).should == pid2
      Process.wait.should == pid1
    end

    # This spec is probably system-dependent.
    it "doesn't block if no child is available when WNOHANG is used" do
      read, write = IO.pipe
      pid = Process.fork do
        read.close
        Signal.trap("TERM") { Process.exit! }
        write << 1
        write.close
        sleep
      end

      Process.wait(pid, Process::WNOHANG).should be_nil

      # wait for the child to setup its TERM handler
      write.close
      read.read(1)
      read.close

      Process.kill("TERM", pid)
      Process.wait.should == pid
    end

    it "always accepts flags=0" do
      pid = Process.spawn(ruby_cmd('exit'))
      Process.wait(-1, 0).should == pid
      lambda { Process.kill(0, pid) }.should raise_error(Errno::ESRCH)
    end
  end
end