Merge pull request #25442 from apolcyn/fix_ruby_e2e_test_port_picking

Fix child process port allocation in ruby end-to-end tests

src/ruby/end2end/channel_closing_client.rb

@@ -30,11 +30,11 @@ class ChannelClosingClientController < ClientControl::ClientController::Service
 end
 
 def main
-  client_control_port = ''
+  parent_controller_port = ''
   server_port = ''
   OptionParser.new do |opts|
-    opts.on('--client_control_port=P', String) do |p|
-      client_control_port = p
+    opts.on('--parent_controller_port=P', String) do |p|
+      parent_controller_port = p
     end
     opts.on('--server_port=P', String) do |p|
       server_port = p
@@ -46,7 +46,8 @@ def main
 
   srv = new_rpc_server_for_testing
   thd = Thread.new do
-    srv.add_http2_port("0.0.0.0:#{client_control_port}", :this_port_is_insecure)
+    port = srv.add_http2_port('localhost:0', :this_port_is_insecure)
+    report_controller_port_to_parent(parent_controller_port, port)
     srv.handle(ChannelClosingClientController.new(ch))
     srv.run
   end

src/ruby/end2end/channel_closing_test.rb

@@ -24,8 +24,8 @@ def main
   server_runner = ServerRunner.new(EchoServerImpl)
   server_port = server_runner.run
   STDERR.puts 'start client'
-  control_stub, client_pid = start_client('channel_closing_client.rb',
-                                          server_port)
+  client_controller = ClientController.new(
+    'channel_closing_client.rb', server_port)
   # sleep to allow time for the client to get into
   # the middle of a "watch connectivity state" call
   sleep 3
@@ -34,7 +34,7 @@ def main
     Timeout.timeout(20) do
       loop do
         begin
-          control_stub.shutdown(ClientControl::Void.new)
+          client_controller.stub.shutdown(ClientControl::Void.new)
           break
         rescue GRPC::BadStatus => e
           STDERR.puts "control_stub.shutdown RPC received error:|#{e}|. " \
@@ -42,12 +42,12 @@ def main
           "so we'll retry the RPC"
         end
       end
-      Process.wait(client_pid)
+      Process.wait(client_controller.client_pid)
     end
   rescue Timeout::Error
-    STDERR.puts "timeout wait for client pid #{client_pid}"
-    Process.kill('SIGKILL', client_pid)
-    Process.wait(client_pid)
+    STDERR.puts "timeout wait for client pid #{client_controller.client_pid}"
+    Process.kill('SIGKILL', client_controller.client_pid)
+    Process.wait(client_controller.client_pid)
     STDERR.puts 'killed client child'
     raise 'Timed out waiting for client process. It likely hangs when a ' \
       'channel is closed while connectivity is watched'

src/ruby/end2end/channel_state_client.rb

@@ -17,15 +17,17 @@
 require_relative './end2end_common'
 
 def main
+  parent_controller_port = ''
   server_port = ''
   OptionParser.new do |opts|
-    opts.on('--client_control_port=P', String) do
-      STDERR.puts 'client_control_port ignored'
+    opts.on('--parent_controller_port=P', String) do |p|
+      parent_controller_port = p
     end
     opts.on('--server_port=P', String) do |p|
       server_port = p
     end
   end.parse!
+  report_controller_port_to_parent(parent_controller_port, 0)
 
   ch = GRPC::Core::Channel.new("localhost:#{server_port}", {},
                                :this_channel_is_insecure)

src/ruby/end2end/channel_state_test.rb

@@ -23,18 +23,19 @@ def main
   server_runner = ServerRunner.new(EchoServerImpl)
   server_port = server_runner.run
   STDERR.puts 'start client'
-  _, client_pid = start_client('channel_state_client.rb', server_port)
+  client_controller = ClientController.new(
+    'channel_state_client.rb', server_port)
   # sleep to allow time for the client to get into
   # the middle of a "watch connectivity state" call
   sleep 3
-  Process.kill('SIGTERM', client_pid)
+  Process.kill('SIGTERM', client_controller.client_pid)
 
   begin
-    Timeout.timeout(10) { Process.wait(client_pid) }
+    Timeout.timeout(10) { Process.wait(client_controller.client_pid) }
   rescue Timeout::Error
-    STDERR.puts "timeout wait for client pid #{client_pid}"
-    Process.kill('SIGKILL', client_pid)
-    Process.wait(client_pid)
+    STDERR.puts "timeout wait for client pid #{client_controller.client_pid}"
+    Process.kill('SIGKILL', client_controller.client_pid)
+    Process.wait(client_controller.client_pid)
     STDERR.puts 'killed client child'
     raise 'Timed out waiting for client process. ' \
            'It likely hangs when ended abruptly'

src/ruby/end2end/client_memory_usage_client.rb

@@ -18,17 +18,19 @@ require_relative './end2end_common'
 require 'objspace'
 
 def main
+  parent_controller_port = ''
   server_port = ''
   loop_count = 200
 
   OptionParser.new do |opts|
-    opts.on('--client_control_port=P', String) do
-      STDERR.puts 'client_control_port ignored'
+    opts.on('--parent_controller_port=P', String) do |p|
+      parent_controller_port = p
     end
     opts.on('--server_port=P', String) do |p|
       server_port = p
     end
   end.parse!
+  report_controller_port_to_parent(parent_controller_port, 0)
 
   loop_count.times do
     stub = Echo::EchoServer::Stub.new("localhost:#{server_port}", :this_channel_is_insecure)

src/ruby/end2end/client_memory_usage_test.rb

@@ -21,9 +21,10 @@ def main
   server_runner = ServerRunner.new(EchoServerImpl)
   server_port = server_runner.run
   STDERR.puts 'start client'
-  _, client_pid = start_client('client_memory_usage_client.rb', server_port)
+  client_controller = ClientController.new(
+    'client_memory_usage_client.rb', server_port)
 
-  Process.wait(client_pid)
+  Process.wait(client_controller.client_pid)
 
   client_exit_code = $CHILD_STATUS
   if client_exit_code != 0

src/ruby/end2end/end2end_common.rb

@@ -43,37 +43,11 @@ class MutableValue
 end
 
 # GreeterServer is simple server that implements the Helloworld Greeter server.
-# This service also has a mechanism to wait for a timeout until the first
-# RPC has been received, which is useful for synchronizing between parent
-# and child processes.
 class EchoServerImpl < Echo::EchoServer::Service
-  def initialize
-    @first_rpc_received_mu = Mutex.new
-    @first_rpc_received_cv = ConditionVariable.new
-    @first_rpc_received = MutableValue.new(false)
-  end
-
   # say_hello implements the SayHello rpc method.
   def echo(echo_req, _)
-    @first_rpc_received_mu.synchronize do
-      @first_rpc_received.value = true
-      @first_rpc_received_cv.broadcast
-    end
     Echo::EchoReply.new(response: echo_req.request)
   end
-
-  def wait_for_first_rpc_received(timeout_seconds)
-    Timeout.timeout(timeout_seconds) do
-      @first_rpc_received_mu.synchronize do
-        until @first_rpc_received.value
-          @first_rpc_received_cv.wait(@first_rpc_received_mu)
-        end
-      end
-    end
-  rescue => e
-    fail "Received error:|#{e}| while waiting for #{timeout_seconds} " \
-         'seconds to receive the first RPC'
-  end
 end
 
 # ServerRunner starts an "echo server" that test clients can make calls to
@@ -105,32 +79,64 @@ class ServerRunner
   end
 end
 
-def start_client(client_main, server_port)
-  this_dir = File.expand_path(File.dirname(__FILE__))
-
-  tmp_server = TCPServer.new(0)
-  client_control_port = tmp_server.local_address.ip_port
-  tmp_server.close
-
-  client_path = File.join(this_dir, client_main)
-  client_pid = Process.spawn(RbConfig.ruby,
-                             client_path,
-                             "--client_control_port=#{client_control_port}",
-                             "--server_port=#{server_port}")
-  control_stub = ClientControl::ClientController::Stub.new(
-    "localhost:#{client_control_port}", :this_channel_is_insecure)
-  [control_stub, client_pid]
-end
-
-def cleanup(control_stub, client_pid, server_runner)
-  control_stub.shutdown(ClientControl::Void.new)
-  Process.wait(client_pid)
-
-  client_exit_code = $CHILD_STATUS
+# ClientController is used to start a child process and communicate
+# with it for test orchestration purposes via RPCs.
+class ClientController < ClientControl::ParentController::Service
+  attr_reader :stub, :client_pid
+
+  def initialize(client_main, server_port)
+    this_dir = File.expand_path(File.dirname(__FILE__))
+    client_path = File.join(this_dir, client_main)
+    @server = new_rpc_server_for_testing(poll_period: 3)
+    port = @server.add_http2_port('localhost:0', :this_port_is_insecure)
+    server_thread = Thread.new do
+      @server.handle(self)
+      @server.run
+    end
+    @server.wait_till_running
+    @client_controller_port_mu = Mutex.new
+    @client_controller_port_cv = ConditionVariable.new
+    @client_controller_port = nil
+    @client_pid = Process.spawn(RbConfig.ruby,
+                                client_path,
+                                "--parent_controller_port=#{port}",
+                                "--server_port=#{server_port}")
+    begin
+      Timeout.timeout(10) do
+        @client_controller_port_mu.synchronize do
+          while @client_controller_port.nil?
+            @client_controller_port_cv.wait(@client_controller_port_mu)
+          end
+        end
+      end
+    rescue => e
+      fail "timeout waiting for child process to report port. error: #{e}"
+    end
+    @server.stop
+    server_thread.join
+    @stub = ClientControl::ClientController::Stub.new(
+      "localhost:#{@client_controller_port}", :this_channel_is_insecure)
+  end
 
-  if client_exit_code != 0
-    fail "term sig test failure: client exit code: #{client_exit_code}"
+  def set_client_controller_port(req, _)
+    @client_controller_port_mu.synchronize do
+      unless @client_controller_port.nil?
+        fail 'client controller port already set'
+      end
+      @client_controller_port = req.port
+      @client_controller_port_cv.broadcast
+    end
+    ClientControl::Void.new
   end
+end
 
-  server_runner.stop
+def report_controller_port_to_parent(parent_controller_port, client_controller_port)
+  unless parent_controller_port.to_i > 0
+    fail "bad parent control port: |#{parent_controller_port}|"
+  end
+  stub = ClientControl::ParentController::Stub.new(
+    "localhost:#{parent_controller_port.to_i}", :this_channel_is_insecure)
+  m = ClientControl::Port.new
+  m.port = client_controller_port.to_i
+  stub.set_client_controller_port(m, deadline: Time.now + 10)
 end

src/ruby/end2end/forking_client_client.rb

@@ -19,10 +19,11 @@
 require_relative './end2end_common'
 
 def main
+  parent_controller_port = ''
   server_port = ''
   OptionParser.new do |opts|
-    opts.on('--client_control_port=P', String) do
-      STDERR.puts 'client control port not used'
+    opts.on('--parent_controller_port=P', String) do |p|
+      parent_controller_port = p
     end
     opts.on('--server_port=P', String) do |p|
       server_port = p
@@ -46,7 +47,9 @@ def main
     raise 'Timed out waiting for client process. ' \
       'It likely hangs when using gRPC after loading it and then forking'
   end
-
+  # don't report the port until now so as to not use grpc before forking
+  report_controller_port_to_parent(parent_controller_port, 0)
+  # check exit status of forked process
   client_exit_code = $CHILD_STATUS
   fail "forked process failed #{client_exit_code}" if client_exit_code != 0
 end

src/ruby/end2end/forking_client_test.rb

@@ -21,17 +21,17 @@ def main
   server_runner = ServerRunner.new(EchoServerImpl)
   server_port = server_runner.run
   STDERR.puts 'start client'
-  _, client_pid = start_client('forking_client_client.rb',
-                               server_port)
+  client_controller = ClientController.new(
+    'forking_client_client.rb', server_port)
 
   begin
     Timeout.timeout(10) do
-      Process.wait(client_pid)
+      Process.wait(client_controller.client_pid)
     end
   rescue Timeout::Error
-    STDERR.puts "timeout wait for client pid #{client_pid}"
-    Process.kill('SIGKILL', client_pid)
-    Process.wait(client_pid)
+    STDERR.puts "timeout wait for client pid #{client_controller.client_pid}"
+    Process.kill('SIGKILL', client_controller.client_pid)
+    Process.wait(client_controller.client_pid)
     STDERR.puts 'killed client child'
     raise 'Timed out waiting for client process. ' \
       'It likely hangs when requiring grpc, then forking, then using grpc '

src/ruby/end2end/graceful_sig_handling_client.rb

@@ -30,21 +30,20 @@ class SigHandlingClientController < ClientControl::ClientController::Service
 end
 
 def main
-  client_control_port = ''
+  parent_controller_port = ''
   server_port = ''
   OptionParser.new do |opts|
-    opts.on('--client_control_port=P', String) do |p|
-      client_control_port = p
+    opts.on('--parent_controller_port=P', String) do |p|
+      parent_controller_port = p
     end
     opts.on('--server_port=P', String) do |p|
       server_port = p
     end
   end.parse!
 
-  # Allow a few seconds to be safe.
   srv = new_rpc_server_for_testing
-  srv.add_http2_port("0.0.0.0:#{client_control_port}",
-                     :this_port_is_insecure)
+  port = srv.add_http2_port('localhost:0',
+                            :this_port_is_insecure)
   stub = Echo::EchoServer::Stub.new("localhost:#{server_port}",
                                     :this_channel_is_insecure)
   control_service = SigHandlingClientController.new(stub)
@@ -53,8 +52,8 @@ def main
     srv.run_till_terminated_or_interrupted(['int'])
   end
   srv.wait_till_running
-  # send a first RPC to notify the parent process that we've started
-  stub.echo(Echo::EchoRequest.new(request: 'client/child started'))
+  # notify the parent process that we're ready to receive signals
+  report_controller_port_to_parent(parent_controller_port, port)
   server_thread.join
 end
 

src/ruby/end2end/graceful_sig_handling_test.rb

@@ -25,16 +25,14 @@ def main
   server_runner = ServerRunner.new(echo_service)
   server_port = server_runner.run
   STDERR.puts 'start client'
-  control_stub, client_pid = start_client('graceful_sig_handling_client.rb', server_port)
-  # use receipt of one RPC to indicate that the child process is
-  # ready
-  echo_service.wait_for_first_rpc_received(20)
+  client_controller = ClientController.new(
+    'graceful_sig_handling_client.rb', server_port)
   # now get the client to send an RPC
-  control_stub.do_echo_rpc(
+  client_controller.stub.do_echo_rpc(
     ClientControl::DoEchoRpcRequest.new(request: 'hello'))
   STDERR.puts 'killing client'
-  Process.kill('SIGINT', client_pid)
-  Process.wait(client_pid)
+  Process.kill('SIGINT', client_controller.client_pid)
+  Process.wait(client_controller.client_pid)
   client_exit_status = $CHILD_STATUS
   if client_exit_status.exited?
     if client_exit_status.exitstatus != 0
@@ -47,7 +45,6 @@ def main
   end
 
   STDERR.puts 'Client ended gracefully'
-  # no need to call cleanup, client should already be dead
   server_runner.stop
 end
 

src/ruby/end2end/graceful_sig_stop_client.rb

@@ -45,11 +45,11 @@ class SigHandlingClientController < ClientControl::ClientController::Service
 end
 
 def main
-  client_control_port = ''
+  parent_controller_port = ''
   server_port = ''
   OptionParser.new do |opts|
-    opts.on('--client_control_port=P', String) do |p|
-      client_control_port = p
+    opts.on('--parent_controller_port=P', String) do |p|
+      parent_controller_port = p
     end
     opts.on('--server_port=P', String) do |p|
       server_port = p
@@ -59,8 +59,8 @@ def main
   # The "shutdown" RPC should end very quickly.
   # Allow a few seconds to be safe.
   srv = new_rpc_server_for_testing(poll_period: 3)
-  srv.add_http2_port("0.0.0.0:#{client_control_port}",
-                     :this_port_is_insecure)
+  port = srv.add_http2_port('localhost:0',
+                            :this_port_is_insecure)
   stub = Echo::EchoServer::Stub.new("localhost:#{server_port}",
                                     :this_channel_is_insecure)
   control_service = SigHandlingClientController.new(srv, stub)
@@ -69,8 +69,8 @@ def main
     srv.run_till_terminated_or_interrupted(['int'])
   end
   srv.wait_till_running
-  # send a first RPC to notify the parent process that we've started
-  stub.echo(Echo::EchoRequest.new(request: 'client/child started'))
+  # notify the parent process that we're ready
+  report_controller_port_to_parent(parent_controller_port, port)
   server_thread.join
   control_service.join_shutdown_thread
 end

src/ruby/end2end/graceful_sig_stop_test.rb

@@ -25,11 +25,12 @@ def main
   server_runner = ServerRunner.new(echo_service)
   server_port = server_runner.run
   STDERR.puts 'start client'
-  control_stub, client_pid = start_client('./graceful_sig_stop_client.rb', server_port)
-  # use receipt of one RPC to indicate that the child process is
-  # ready
-  echo_service.wait_for_first_rpc_received(20)
-  cleanup(control_stub, client_pid, server_runner)
+  client_controller = ClientController.new(
+    './graceful_sig_stop_client.rb', server_port)
+  client_controller.stub.shutdown(ClientControl::Void.new)
+  Process.wait(client_controller.client_pid)
+  fail "client exit code: #{$CHILD_STATUS}" unless $CHILD_STATUS.to_i.zero?
+  server_runner.stop
 end
 
 main

src/ruby/end2end/killed_client_thread_client.rb

@@ -20,15 +20,17 @@
 require_relative './end2end_common'
 
 def main
+  parent_controller_port = ''
   server_port = ''
   OptionParser.new do |opts|
-    opts.on('--client_control_port=P', String) do
-      STDERR.puts 'client control port not used'
+    opts.on('--parent_controller_port=P', String) do |p|
+      parent_controller_port = p
     end
     opts.on('--server_port=P', String) do |p|
       server_port = p
     end
   end.parse!
+  report_controller_port_to_parent(parent_controller_port, 0)
 
   thd = Thread.new do
     stub = Echo::EchoServer::Stub.new("localhost:#{server_port}",

src/ruby/end2end/killed_client_thread_test.rb

@@ -35,13 +35,13 @@ end
 def main
   STDERR.puts 'start server'
 
-  client_started = false
-  client_started_mu = Mutex.new
-  client_started_cv = ConditionVariable.new
+  received_rpc = false
+  received_rpc_mu = Mutex.new
+  received_rpc_cv = ConditionVariable.new
   received_rpc_callback = proc do
-    client_started_mu.synchronize do
-      client_started = true
-      client_started_cv.signal
+    received_rpc_mu.synchronize do
+      received_rpc = true
+      received_rpc_cv.signal
     end
   end
 
@@ -52,26 +52,26 @@ def main
   server_runner = ServerRunner.new(service_impl, rpc_server_args: rpc_server_args)
   server_port = server_runner.run
   STDERR.puts 'start client'
-  _, client_pid = start_client('killed_client_thread_client.rb',
-                               server_port)
+  client_controller = ClientController.new(
+    'killed_client_thread_client.rb', server_port)
 
-  client_started_mu.synchronize do
-    client_started_cv.wait(client_started_mu) until client_started
+  received_rpc_mu.synchronize do
+    received_rpc_cv.wait(received_rpc_mu) until received_rpc
   end
 
   # SIGTERM the child process now that it's
   # in the middle of an RPC (happening on a non-main thread)
-  Process.kill('SIGTERM', client_pid)
+  Process.kill('SIGTERM', client_controller.client_pid)
   STDERR.puts 'sent shutdown'
 
   begin
     Timeout.timeout(10) do
-      Process.wait(client_pid)
+      Process.wait(client_controller.client_pid)
     end
   rescue Timeout::Error
-    STDERR.puts "timeout wait for client pid #{client_pid}"
-    Process.kill('SIGKILL', client_pid)
-    Process.wait(client_pid)
+    STDERR.puts "timeout wait for client pid #{client_controller.client_pid}"
+    Process.kill('SIGKILL', client_controller.client_pid)
+    Process.wait(client_controller.client_pid)
     STDERR.puts 'killed client child'
     raise 'Timed out waiting for client process. ' \
       'It likely hangs when killed while in the middle of an rpc'

src/ruby/end2end/lib/client_control_pb.rb

@@ -4,14 +4,20 @@
 require 'google/protobuf'
 
 Google::Protobuf::DescriptorPool.generated_pool.build do
-  add_message "client_control.DoEchoRpcRequest" do
-    optional :request, :string, 1
-  end
-  add_message "client_control.Void" do
+  add_file("client_control.proto", :syntax => :proto3) do
+    add_message "client_control.DoEchoRpcRequest" do
+      optional :request, :string, 1
+    end
+    add_message "client_control.Void" do
+    end
+    add_message "client_control.Port" do
+      optional :port, :int32, 1
+    end
   end
 end
 
 module ClientControl
-  DoEchoRpcRequest = Google::Protobuf::DescriptorPool.generated_pool.lookup("client_control.DoEchoRpcRequest").msgclass
-  Void = Google::Protobuf::DescriptorPool.generated_pool.lookup("client_control.Void").msgclass
+  DoEchoRpcRequest = ::Google::Protobuf::DescriptorPool.generated_pool.lookup("client_control.DoEchoRpcRequest").msgclass
+  Void = ::Google::Protobuf::DescriptorPool.generated_pool.lookup("client_control.Void").msgclass
+  Port = ::Google::Protobuf::DescriptorPool.generated_pool.lookup("client_control.Port").msgclass
 end

src/ruby/end2end/lib/client_control_services_pb.rb

@@ -29,8 +29,22 @@ module ClientControl
       self.unmarshal_class_method = :decode
       self.service_name = 'client_control.ClientController'
 
-      rpc :DoEchoRpc, DoEchoRpcRequest, Void
-      rpc :Shutdown, Void, Void
+      rpc :DoEchoRpc, ::ClientControl::DoEchoRpcRequest, ::ClientControl::Void
+      rpc :Shutdown, ::ClientControl::Void, ::ClientControl::Void
+    end
+
+    Stub = Service.rpc_stub_class
+  end
+  module ParentController
+    class Service
+
+      include GRPC::GenericService
+
+      self.marshal_class_method = :encode
+      self.unmarshal_class_method = :decode
+      self.service_name = 'client_control.ParentController'
+
+      rpc :SetClientControllerPort, ::ClientControl::Port, ::ClientControl::Void
     end
 
     Stub = Service.rpc_stub_class

src/ruby/end2end/lib/echo_pb.rb

@@ -4,15 +4,17 @@
 require 'google/protobuf'
 
 Google::Protobuf::DescriptorPool.generated_pool.build do
-  add_message "echo.EchoRequest" do
-    optional :request, :string, 1
-  end
-  add_message "echo.EchoReply" do
-    optional :response, :string, 1
+  add_file("echo.proto", :syntax => :proto3) do
+    add_message "echo.EchoRequest" do
+      optional :request, :string, 1
+    end
+    add_message "echo.EchoReply" do
+      optional :response, :string, 1
+    end
   end
 end
 
 module Echo
-  EchoRequest = Google::Protobuf::DescriptorPool.generated_pool.lookup("echo.EchoRequest").msgclass
-  EchoReply = Google::Protobuf::DescriptorPool.generated_pool.lookup("echo.EchoReply").msgclass
+  EchoRequest = ::Google::Protobuf::DescriptorPool.generated_pool.lookup("echo.EchoRequest").msgclass
+  EchoReply = ::Google::Protobuf::DescriptorPool.generated_pool.lookup("echo.EchoReply").msgclass
 end

src/ruby/end2end/lib/echo_services_pb.rb

@@ -29,7 +29,7 @@ module Echo
       self.unmarshal_class_method = :decode
       self.service_name = 'echo.EchoServer'
 
-      rpc :Echo, EchoRequest, EchoReply
+      rpc :Echo, ::Echo::EchoRequest, ::Echo::EchoReply
     end
 
     Stub = Service.rpc_stub_class

src/ruby/end2end/protos/client_control.proto

@@ -26,3 +26,11 @@ message DoEchoRpcRequest {
 }
 
 message Void{}
+
+service ParentController {
+  rpc SetClientControllerPort(Port) returns (Void) {}
+}
+
+message Port {
+  int32 port = 1;
+}

src/ruby/end2end/sig_handling_client.rb

@@ -45,11 +45,11 @@ class SigHandlingClientController < ClientControl::ClientController::Service
 end
 
 def main
-  client_control_port = ''
+  parent_controller_port = ''
   server_port = ''
   OptionParser.new do |opts|
-    opts.on('--client_control_port=P', String) do |p|
-      client_control_port = p
+    opts.on('--parent_controller_port=P', String) do |p|
+      parent_controller_port = p
     end
     opts.on('--server_port=P', String) do |p|
       server_port = p
@@ -67,8 +67,8 @@ def main
   # The "shutdown" RPC should end very quickly.
   # Allow a few seconds to be safe.
   srv = new_rpc_server_for_testing(poll_period: 3)
-  srv.add_http2_port("0.0.0.0:#{client_control_port}",
-                     :this_port_is_insecure)
+  port = srv.add_http2_port('localhost:0',
+                            :this_port_is_insecure)
   stub = Echo::EchoServer::Stub.new("localhost:#{server_port}",
                                     :this_channel_is_insecure)
   control_service = SigHandlingClientController.new(srv, stub)
@@ -77,8 +77,8 @@ def main
     srv.run
   end
   srv.wait_till_running
-  # send a first RPC to notify the parent process that we've started
-  stub.echo(Echo::EchoRequest.new(request: 'client/child started'))
+  # notify the parent process that we're ready
+  report_controller_port_to_parent(parent_controller_port, port)
   server_thread.join
   control_service.join_shutdown_thread
 end

src/ruby/end2end/sig_handling_test.rb

@@ -25,19 +25,20 @@ def main
   server_runner = ServerRunner.new(echo_service)
   server_port = server_runner.run
   STDERR.puts 'start client'
-  control_stub, client_pid = start_client('sig_handling_client.rb', server_port)
-  # use receipt of one RPC to indicate that the child process is
-  # ready
-  echo_service.wait_for_first_rpc_received(20)
+  client_controller = ClientController.new(
+    'sig_handling_client.rb', server_port)
   count = 0
   while count < 5
-    control_stub.do_echo_rpc(
+    client_controller.stub.do_echo_rpc(
       ClientControl::DoEchoRpcRequest.new(request: 'hello'))
-    Process.kill('SIGTERM', client_pid)
-    Process.kill('SIGINT', client_pid)
+    Process.kill('SIGTERM', client_controller.client_pid)
+    Process.kill('SIGINT', client_controller.client_pid)
     count += 1
   end
-  cleanup(control_stub, client_pid, server_runner)
+  client_controller.stub.shutdown(ClientControl::Void.new)
+  Process.wait(client_controller.client_pid)
+  fail "client exit code: #{$CHILD_STATUS}" unless $CHILD_STATUS.to_i.zero?
+  server_runner.stop
 end
 
 main

src/ruby/end2end/sig_int_during_channel_watch_client.rb

@@ -22,10 +22,11 @@ require_relative './end2end_common'
 # middle of a blocking connectivity_state call.
 def main
   STDERR.puts 'sig_int_during_channel_watch_client.rb main'
+  parent_controller_port = ''
   server_port = ''
   OptionParser.new do |opts|
-    opts.on('--client_control_port=P', String) do
-      STDERR.puts 'client_control_port not used'
+    opts.on('--parent_controller_port=P', String) do |p|
+      parent_controller_port = p
     end
     opts.on('--server_port=P', String) do |p|
       server_port = p
@@ -34,16 +35,8 @@ def main
 
   trap('SIGINT') { exit 0 }
   STDERR.puts 'sig_int_during_channel_watch_client.rb: SIGINT trap has been set'
-  # First, notify the parent process that we're ready for a SIGINT by sending
-  # an RPC
-  begin
-    stub = Echo::EchoServer::Stub.new(
-      "localhost:#{server_port}", :this_channel_is_insecure)
-    stub.echo(ClientControl::DoEchoRpcRequest.new)
-  rescue => e
-    fail "received error:|#{e}| while sending an RPC to the parent process " \
-         'to indicate that the SIGINT trap has been set'
-  end
+  # notify the parent process that we're ready for signals
+  report_controller_port_to_parent(parent_controller_port, 0)
 
   thd = Thread.new do
     child_thread_channel = GRPC::Core::Channel.new("localhost:#{server_port}",

src/ruby/end2end/sig_int_during_channel_watch_test.rb

@@ -25,23 +25,20 @@ def main
   server_runner = ServerRunner.new(echo_service)
   server_port = server_runner.run
   STDERR.puts 'start client'
-  _, client_pid = start_client('sig_int_during_channel_watch_client.rb',
-                               server_port)
-  # use receipt of one RPC to indicate that the child process is
-  # ready for a SIGINT
-  echo_service.wait_for_first_rpc_received(20)
+  client_controller = ClientController.new(
+    'sig_int_during_channel_watch_client.rb', server_port)
   # give time for the client to get into the middle
   # of a channel state watch call
   sleep 1
-  Process.kill('SIGINT', client_pid)
+  Process.kill('SIGINT', client_controller.client_pid)
   begin
     Timeout.timeout(10) do
-      Process.wait(client_pid)
+      Process.wait(client_controller.client_pid)
     end
   rescue Timeout::Error
-    STDERR.puts "timeout wait for client pid #{client_pid}"
-    Process.kill('SIGKILL', client_pid)
-    Process.wait(client_pid)
+    STDERR.puts "timeout wait for client pid #{client_controller.client_pid}"
+    Process.kill('SIGKILL', client_controller.client_pid)
+    Process.wait(client_controller.client_pid)
     STDERR.puts 'killed client child'
     raise 'Timed out waiting for client process. It likely hangs when a ' \
       'SIGINT is sent while there is an active connectivity_state call'