Remove ChildProcess gem dependency

Process.spawn is cross-platform in Ruby 2.7+ and ChildProcess is not
actively maintained at the moment. Fixes #11251.

WORKSPACE

@@ -324,9 +324,9 @@ pin_browsers()
 
 http_archive(
     name = "rules_ruby",
-    sha256 = "966ef280a3ecb24867b2f67d73bb3ad3c59b4a7beefb67abbcd79b0dff0a5679",
-    strip_prefix = "rules_ruby_simple-078c24fd29a9e1717990fa2fce15e1cb053f18a3",
-    url = "https://github.com/p0deje/rules_ruby_simple/archive/078c24fd29a9e1717990fa2fce15e1cb053f18a3.zip",
+    sha256 = "bb0bffb0285ff8fa9a967fc2580ddf3b511818a6baf269dcd6c5c6076c4921d8",
+    strip_prefix = "rules_ruby-c3cefa71d0111a04c9ce0672c65d376262d8d975",
+    url = "https://github.com/p0deje/rules_ruby/archive/c3cefa71d0111a04c9ce0672c65d376262d8d975.zip",
 )
 
 load(

rb/lib/selenium/server.rb

@@ -17,7 +17,7 @@
 # specific language governing permissions and limitations
 # under the License.
 
-require 'childprocess'
+require 'selenium/webdriver/common/child_process'
 require 'selenium/webdriver/common/socket_poller'
 require 'net/http'
 
@@ -237,7 +237,7 @@ def stop_process
 
       begin
         @process.poll_for_exit(5)
-      rescue ChildProcess::TimeoutError
+      rescue WebDriver::Common::ChildProcess::TimeoutError
         @process.stop
       end
     rescue Errno::ECHILD
@@ -252,16 +252,13 @@ def process
         properties = @additional_args.dup - @additional_args.delete_if { |arg| arg[/^-D/] }
         args = ['-jar', @jar, @role, '--port', @port.to_s]
         server_command = ['java'] + properties + args + @additional_args
-        cp = ChildProcess.build(*server_command)
+        cp = WebDriver::Common::ChildProcess.build(*server_command)
         WebDriver.logger.debug("Executing Process #{server_command}")
 
-        io = cp.io
-
         if @log.is_a?(String)
-          @log_file = File.open(@log, 'w')
-          io.stdout = io.stderr = @log_file
+          cp.io = @log
         elsif @log
-          io.inherit!
+          cp.io = :out
         end
 
         cp.detach = @background

rb/lib/selenium/webdriver.rb

@@ -17,7 +17,6 @@
 # specific language governing permissions and limitations
 # under the License.
 
-require 'childprocess'
 require 'tmpdir'
 require 'fileutils'
 require 'date'

rb/lib/selenium/webdriver/common.rb

@@ -96,3 +96,4 @@
 require 'selenium/webdriver/common/element'
 require 'selenium/webdriver/common/shadow_root'
 require 'selenium/webdriver/common/websocket_connection'
+require 'selenium/webdriver/common/child_process'

rb/lib/selenium/webdriver/common/child_process.rb

@@ -0,0 +1,114 @@
+# frozen_string_literal: true
+
+# Licensed to the Software Freedom Conservancy (SFC) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The SFC licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+module Selenium
+  module WebDriver
+    module Common
+
+      #
+      # @api private
+      #
+
+      class ChildProcess
+        TimeoutError = Class.new(StandardError)
+
+        SIGTERM = 'TERM'
+        SIGKILL = 'KILL'
+
+        POLL_INTERVAL = 0.1
+
+        attr_accessor :detach
+        attr_writer :io
+
+        def self.build(*command)
+          new(*command)
+        end
+
+        def initialize(*command)
+          @command = command
+          @detach = false
+          @pid = nil
+          @status = nil
+        end
+
+        def io
+          @io ||= Platform.null_device
+        end
+
+        def start
+          options = {%i(out err) => io}
+          options[:pgroup] = true unless Platform.windows? # NOTE: this is a bug only in Windows 7
+
+          WebDriver.logger.debug("Starting process: #{@command} with #{options}")
+          @pid = Process.spawn(*@command, options)
+          WebDriver.logger.debug("  -> pid: #{@pid}")
+
+          Process.detach(@pid) if detach
+        end
+
+        def stop(timeout = 3)
+          return unless @pid
+          return if exited?
+
+          WebDriver.logger.debug("Sending TERM to process: #{@pid}")
+          Process.kill(SIGTERM, @pid)
+          poll_for_exit(timeout)
+
+          WebDriver.logger.debug("  -> stopped #{@pid}")
+        rescue TimeoutError
+          WebDriver.logger.debug("    -> sending KILL to process: #{@pid}")
+          Process.kill(SIGKILL, @pid)
+          wait
+          WebDriver.logger.debug("      -> killed #{@pid}")
+        end
+
+        def alive?
+          @pid && !exited?
+        end
+
+        def exited?
+          return unless @pid
+
+          WebDriver.logger.debug("Checking if #{@pid} is exited")
+          _, @status = Process.waitpid2(@pid, Process::WNOHANG | Process::WUNTRACED) if @status.nil?
+          return if @status.nil?
+
+          WebDriver.logger.debug("  -> exit code is #{@status.exitstatus}")
+          @status.exited?
+        end
+
+        def poll_for_exit(timeout)
+          WebDriver.logger.debug("Polling #{timeout} seconds for exit of #{@pid}")
+
+          end_time = Time.now + timeout
+          sleep POLL_INTERVAL until exited? || Time.now > end_time
+
+          raise TimeoutError, "  ->  #{@pid} still alive after #{timeout} seconds" unless exited?
+        end
+
+        def wait
+          return if exited?
+
+          _, @status = Process.waitpid2(@pid)
+        end
+
+      end # ChildProcess
+    end # Common
+  end # WebDriver
+end # Selenium

rb/lib/selenium/webdriver/common/service_manager.rb

@@ -78,13 +78,8 @@ def uri
 
       def build_process(*command)
         WebDriver.logger.debug("Executing Process #{command}")
-        @process = ChildProcess.build(*command)
-        if WebDriver.logger.debug?
-          @process.io.stdout = @process.io.stderr = WebDriver.logger.io
-        elsif Platform.jruby?
-          # Apparently we need to read the output of drivers on JRuby.
-          @process.io.stdout = @process.io.stderr = File.new(Platform.null_device, 'w')
-        end
+        @process = Common::ChildProcess.build(*command)
+        @process.io = WebDriver.logger.io if WebDriver.logger.debug?
 
         @process
       end
@@ -104,16 +99,13 @@ def find_free_port
 
       def start_process
         @process = build_process(@executable_path, "--port=#{@port}", *@extra_args)
-        # NOTE: this is a bug only in Windows 7
-        @process.leader = true unless Platform.windows?
         @process.start
       end
 
       def stop_process
         return if process_exited?
 
         @process.stop STOP_TIMEOUT
-        @process.io.stdout.close if Platform.jruby? && !WebDriver.logger.debug?
       end
 
       def stop_server

rb/lib/selenium/webdriver/common/socket_lock.rb

@@ -66,8 +66,7 @@ def release
 
       def can_lock?
         @server = TCPServer.new(Platform.localhost, @port)
-        ChildProcess.close_on_exec @server
-
+        @server.close_on_exec = true
         true
       rescue SocketError, Errno::EADDRINUSE, Errno::EBADF => e
         WebDriver.logger.debug("#{self}: #{e.message}")

rb/lib/selenium/webdriver/support.rb

@@ -20,6 +20,7 @@
 require 'selenium/webdriver/support/event_firing_bridge'
 require 'selenium/webdriver/support/abstract_event_listener'
 require 'selenium/webdriver/support/block_event_listener'
+require 'selenium/webdriver/support/child_process'
 require 'selenium/webdriver/support/escaper'
 require 'selenium/webdriver/support/select'
 require 'selenium/webdriver/support/color'

rb/lib/selenium/webdriver/support/child_process.rb

@@ -0,0 +1,114 @@
+# frozen_string_literal: true
+
+# Licensed to the Software Freedom Conservancy (SFC) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The SFC licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+module Selenium
+  module WebDriver
+    module Support
+
+      #
+      # @api private
+      #
+
+      class ChildProcess
+        TimeoutError = Class.new(StandardError)
+
+        SIGTERM = 'TERM'
+        SIGKILL = 'KILL'
+
+        POLL_INTERVAL = 0.1
+
+        attr_accessor :detach
+        attr_writer :io
+
+        def self.build(*command)
+          new(*command)
+        end
+
+        def initialize(*command)
+          @command = command
+          @detach = false
+          @pid = nil
+          @status = nil
+        end
+
+        def io
+          @io ||= Platform.null_device
+        end
+
+        def start
+          options = {%i(out err) => io}
+          options[:pgroup] = true unless Platform.windows? # NOTE: this is a bug only in Windows 7
+
+          WebDriver.logger.debug("Starting process: #{@command} with #{options}")
+          @pid = Process.spawn(*@command, options)
+          WebDriver.logger.debug("  -> pid: #{@pid}")
+
+          Process.detach(@pid) if detach
+        end
+
+        def stop(timeout = 3)
+          return unless @pid
+          return if exited?
+
+          WebDriver.logger.debug("Sending TERM to process: #{@pid}")
+          Process.kill(SIGTERM, @pid)
+          poll_for_exit(timeout)
+
+          WebDriver.logger.debug("  -> stopped #{@pid}")
+        rescue TimeoutError
+          WebDriver.logger.debug("    -> sending KILL to process: #{@pid}")
+          Process.kill(SIGKILL, @pid)
+          wait
+          WebDriver.logger.debug("      -> killed #{@pid}")
+        end
+
+        def alive?
+          @pid && !exited?
+        end
+
+        def exited?
+          return unless @pid
+
+          WebDriver.logger.debug("Checking if #{@pid} is exited")
+          _, @status = Process.waitpid2(@pid, Process::WNOHANG | Process::WUNTRACED) if @status.nil?
+          return if @status.nil?
+
+          WebDriver.logger.debug("  -> exit code is #{@status.exitstatus}")
+          @status.exited?
+        end
+
+        def poll_for_exit(timeout)
+          WebDriver.logger.debug("Polling #{timeout} seconds for exit of #{@pid}")
+
+          end_time = Time.now + timeout
+          sleep POLL_INTERVAL until exited? || Time.now > end_time
+
+          raise TimeoutError, "  ->  #{@pid} still alive after #{timeout} seconds" unless exited?
+        end
+
+        def wait
+          return if exited?
+
+          _, @status = Process.waitpid2(@pid)
+        end
+
+      end # ChildProcess
+    end # Support
+  end # WebDriver
+end # Selenium

rb/selenium-webdriver.gemspec

@@ -48,13 +48,10 @@ Gem::Specification.new do |s|
   s.bindir = 'bin'
   s.require_paths = ['lib']
 
-  s.add_runtime_dependency 'childprocess', ['>= 0.5', '< 5.0']
   s.add_runtime_dependency 'rexml', ['~> 3.2', '>= 3.2.5']
   s.add_runtime_dependency 'rubyzip', ['>= 1.2.2', '< 3.0']
   s.add_runtime_dependency 'websocket', ['~> 1.0']
 
-  # childprocess requires ffi on windows but doesn't declare it in its dependencies
-  s.add_development_dependency 'ffi'
   s.add_development_dependency 'pry', ['~> 0.14']
   s.add_development_dependency 'rack', ['~> 2.0']
   s.add_development_dependency 'rake'