Merge pull request #11764 from apolcyn/fix_ruby_socket_leak

Release resources more eagerly on ruby server

src/ruby/lib/grpc/generic/active_call.rb

@@ -40,13 +40,13 @@ end
 module GRPC
   # The ActiveCall class provides simple methods for sending marshallable
   # data to a call
-  class ActiveCall
+  class ActiveCall # rubocop:disable Metrics/ClassLength
     include Core::TimeConsts
     include Core::CallOps
     extend Forwardable
-    attr_reader :deadline, :metadata_sent, :metadata_to_send
+    attr_reader :deadline, :metadata_sent, :metadata_to_send, :peer, :peer_cert
     def_delegators :@call, :cancel, :metadata, :write_flag, :write_flag=,
-                   :peer, :peer_cert, :trailing_metadata
+                   :trailing_metadata, :status
 
     # client_invoke begins a client invocation.
     #
@@ -100,6 +100,18 @@ module GRPC
       fail(ArgumentError, 'Already sent md') if started && metadata_to_send
       @metadata_to_send = metadata_to_send || {} unless started
       @send_initial_md_mutex = Mutex.new
+
+      @output_stream_done = false
+      @input_stream_done = false
+      @call_finished = false
+      @call_finished_mu = Mutex.new
+
+      @client_call_executed = false
+      @client_call_executed_mu = Mutex.new
+
+      # set the peer now so that the accessor can still function
+      # after the server closes the call
+      @peer = call.peer
     end
 
     # Sends the initial metadata that has yet to be sent.
@@ -142,11 +154,9 @@ module GRPC
       Operation.new(self)
     end
 
-    # finished waits until a client call is completed.
-    #
-    # It blocks until the remote endpoint acknowledges by sending a status.
-    def finished
+    def receive_and_check_status
       batch_result = @call.run_batch(RECV_STATUS_ON_CLIENT => nil)
+      set_input_stream_done
       attach_status_results_and_complete_call(batch_result)
     end
 
@@ -155,8 +165,6 @@ module GRPC
         @call.trailing_metadata = recv_status_batch_result.status.metadata
       end
       @call.status = recv_status_batch_result.status
-      @call.close
-      op_is_done
 
       # The RECV_STATUS in run_batch always succeeds
       # Check the status for a bad status or failed run batch
@@ -193,9 +201,19 @@ module GRPC
       }
       ops[RECV_CLOSE_ON_SERVER] = nil if assert_finished
       @call.run_batch(ops)
+      set_output_stream_done
+
       nil
     end
 
+    # Intended for use on server-side calls when a single request from
+    # the client is expected (i.e., unary and server-streaming RPC types).
+    def read_unary_request
+      req = remote_read
+      set_input_stream_done
+      req
+    end
+
     def server_unary_response(req, trailing_metadata: {},
                               code: Core::StatusCodes::OK, details: 'OK')
       ops = {}
@@ -211,6 +229,7 @@ module GRPC
       ops[RECV_CLOSE_ON_SERVER] = nil
 
       @call.run_batch(ops)
+      set_output_stream_done
     end
 
     # remote_read reads a response from the remote endpoint.
@@ -241,6 +260,8 @@ module GRPC
 
     # each_remote_read passes each response to the given block or returns an
     # enumerator the responses if no block is given.
+    # Used to generate the request enumerable for
+    # server-side client-streaming RPC's.
     #
     # == Enumerator ==
     #
@@ -258,10 +279,14 @@ module GRPC
     # @return [Enumerator] if no block was given
     def each_remote_read
       return enum_for(:each_remote_read) unless block_given?
-      loop do
-        resp = remote_read
-        break if resp.nil?  # the last response was received
-        yield resp
+      begin
+        loop do
+          resp = remote_read
+          break if resp.nil?  # the last response was received
+          yield resp
+        end
+      ensure
+        set_input_stream_done
       end
     end
 
@@ -287,13 +312,17 @@ module GRPC
     # @return [Enumerator] if no block was given
     def each_remote_read_then_finish
       return enum_for(:each_remote_read_then_finish) unless block_given?
-      loop do
-        resp = remote_read
-        if resp.nil?  # the last response was received, but not finished yet
-          finished
-          break
+      begin
+        loop do
+          resp = remote_read
+          if resp.nil?  # the last response was received
+            receive_and_check_status
+            break
+          end
+          yield resp
         end
-        yield resp
+      ensure
+        set_input_stream_done
       end
     end
 
@@ -305,6 +334,7 @@ module GRPC
     # a list, multiple metadata for its key are sent
     # @return [Object] the response received from the server
     def request_response(req, metadata: {})
+      raise_error_if_already_executed
       ops = {
         SEND_MESSAGE => @marshal.call(req),
         SEND_CLOSE_FROM_CLIENT => nil,
@@ -319,7 +349,15 @@ module GRPC
         end
         @metadata_sent = true
       end
-      batch_result = @call.run_batch(ops)
+
+      begin
+        batch_result = @call.run_batch(ops)
+        # no need to check for cancellation after a CallError because this
+        # batch contains a RECV_STATUS op
+      ensure
+        set_input_stream_done
+        set_output_stream_done
+      end
 
       @call.metadata = batch_result.metadata
       attach_status_results_and_complete_call(batch_result)
@@ -339,10 +377,20 @@ module GRPC
     # a list, multiple metadata for its key are sent
     # @return [Object] the response received from the server
     def client_streamer(requests, metadata: {})
-      # Metadata might have already been sent if this is an operation view
-      merge_metadata_and_send_if_not_already_sent(metadata)
+      raise_error_if_already_executed
+      begin
+        merge_metadata_and_send_if_not_already_sent(metadata)
+        requests.each { |r| @call.run_batch(SEND_MESSAGE => @marshal.call(r)) }
+      rescue GRPC::Core::CallError => e
+        receive_and_check_status # check for Cancelled
+        raise e
+      rescue => e
+        set_input_stream_done
+        raise e
+      ensure
+        set_output_stream_done
+      end
 
-      requests.each { |r| @call.run_batch(SEND_MESSAGE => @marshal.call(r)) }
       batch_result = @call.run_batch(
         SEND_CLOSE_FROM_CLIENT => nil,
         RECV_INITIAL_METADATA => nil,
@@ -350,12 +398,11 @@ module GRPC
         RECV_STATUS_ON_CLIENT => nil
       )
 
+      set_input_stream_done
+
       @call.metadata = batch_result.metadata
       attach_status_results_and_complete_call(batch_result)
       get_message_from_batch_result(batch_result)
-    rescue GRPC::Core::CallError => e
-      finished  # checks for Cancelled
-      raise e
     end
 
     # server_streamer sends one request to the GRPC server, which yields a
@@ -373,6 +420,7 @@ module GRPC
     # a list, multiple metadata for its key are sent
     # @return [Enumerator|nil] a response Enumerator
     def server_streamer(req, metadata: {})
+      raise_error_if_already_executed
       ops = {
         SEND_MESSAGE => @marshal.call(req),
         SEND_CLOSE_FROM_CLIENT => nil
@@ -384,13 +432,22 @@ module GRPC
         end
         @metadata_sent = true
       end
-      @call.run_batch(ops)
+
+      begin
+        @call.run_batch(ops)
+      rescue GRPC::Core::CallError => e
+        receive_and_check_status # checks for Cancelled
+        raise e
+      rescue => e
+        set_input_stream_done
+        raise e
+      ensure
+        set_output_stream_done
+      end
+
       replies = enum_for(:each_remote_read_then_finish)
       return replies unless block_given?
       replies.each { |r| yield r }
-    rescue GRPC::Core::CallError => e
-      finished  # checks for Cancelled
-      raise e
     end
 
     # bidi_streamer sends a stream of requests to the GRPC server, and yields
@@ -421,6 +478,7 @@ module GRPC
     # a list, multiple metadata for its key are sent
     # @return [Enumerator, nil] a response Enumerator
     def bidi_streamer(requests, metadata: {}, &blk)
+      raise_error_if_already_executed
       # Metadata might have already been sent if this is an operation view
       merge_metadata_and_send_if_not_already_sent(metadata)
       bd = BidiCall.new(@call,
@@ -428,7 +486,10 @@ module GRPC
                         @unmarshal,
                         metadata_received: @metadata_received)
 
-      bd.run_on_client(requests, @op_notifier, &blk)
+      bd.run_on_client(requests,
+                       proc { set_input_stream_done },
+                       proc { set_output_stream_done },
+                       &blk)
     end
 
     # run_server_bidi orchestrates a BiDi stream processing on a server.
@@ -449,7 +510,7 @@ module GRPC
                         metadata_received: @metadata_received,
                         req_view: MultiReqView.new(self))
 
-      bd.run_on_server(gen_each_reply)
+      bd.run_on_server(gen_each_reply, proc { set_input_stream_done })
     end
 
     # Waits till an operation completes
@@ -459,7 +520,8 @@ module GRPC
       @op_notifier.wait
     end
 
-    # Signals that an operation is done
+    # Signals that an operation is done.
+    # Only relevant on the client-side (this is a no-op on the server-side)
     def op_is_done
       return if @op_notifier.nil?
       @op_notifier.notify(self)
@@ -484,8 +546,40 @@ module GRPC
       end
     end
 
+    def attach_peer_cert(peer_cert)
+      @peer_cert = peer_cert
+    end
+
     private
 
+    # To be called once the "input stream" has been completelly
+    # read through (i.e, done reading from client or received status)
+    # note this is idempotent
+    def set_input_stream_done
+      @call_finished_mu.synchronize do
+        @input_stream_done = true
+        maybe_finish_and_close_call_locked
+      end
+    end
+
+    # To be called once the "output stream" has been completelly
+    # sent through (i.e, done sending from client or sent status)
+    # note this is idempotent
+    def set_output_stream_done
+      @call_finished_mu.synchronize do
+        @output_stream_done = true
+        maybe_finish_and_close_call_locked
+      end
+    end
+
+    def maybe_finish_and_close_call_locked
+      return unless @output_stream_done && @input_stream_done
+      return if @call_finished
+      @call_finished = true
+      op_is_done
+      @call.close
+    end
+
     # Starts the call if not already started
     # @param metadata [Hash] metadata to be sent to the server. If a value is
     # a list, multiple metadata for its key are sent
@@ -493,6 +587,15 @@ module GRPC
       merge_metadata_to_send(metadata) && send_initial_metadata
     end
 
+    def raise_error_if_already_executed
+      @client_call_executed_mu.synchronize do
+        if @client_call_executed
+          fail GRPC::Core::CallError, 'attempting to re-run a call'
+        end
+        @client_call_executed = true
+      end
+    end
+
     def self.view_class(*visible_methods)
       Class.new do
         extend ::Forwardable
@@ -518,6 +621,7 @@ module GRPC
     # server client_streamer handlers.
     MultiReqView = view_class(:cancelled?, :deadline,
                               :each_remote_read, :metadata, :output_metadata,
+                              :peer, :peer_cert,
                               :send_initial_metadata,
                               :metadata_to_send,
                               :merge_metadata_to_send,

src/ruby/lib/grpc/generic/bidi_call.rb

@@ -62,12 +62,19 @@ module GRPC
     # block that can be invoked with each response.
     #
     # @param requests the Enumerable of requests to send
-    # @param op_notifier a Notifier used to signal completion
+    # @param set_input_stream_done [Proc] called back when we're done
+    #   reading the input stream
+    # @param set_input_stream_done [Proc] called back when we're done
+    #   sending data on the output stream
     # @return an Enumerator of requests to yield
-    def run_on_client(requests, op_notifier, &blk)
-      @op_notifier = op_notifier
-      @enq_th = Thread.new { write_loop(requests) }
-      read_loop(&blk)
+    def run_on_client(requests,
+                      set_input_stream_done,
+                      set_output_stream_done,
+                      &blk)
+      @enq_th = Thread.new do
+        write_loop(requests, set_output_stream_done: set_output_stream_done)
+      end
+      read_loop(set_input_stream_done, &blk)
     end
 
     # Begins orchestration of the Bidi stream for a server generating replies.
@@ -81,12 +88,17 @@ module GRPC
     # produced by gen_each_reply could ignore the received_msgs
     #
     # @param gen_each_reply [Proc] generates the BiDi stream replies.
-    def run_on_server(gen_each_reply)
+    # @param set_input_steam_done [Proc] call back to call when
+    #   the reads have been completely read through.
+    def run_on_server(gen_each_reply, set_input_stream_done)
       # Pass in the optional call object parameter if possible
       if gen_each_reply.arity == 1
-        replys = gen_each_reply.call(read_loop(is_client: false))
+        replys = gen_each_reply.call(
+          read_loop(set_input_stream_done, is_client: false))
       elsif gen_each_reply.arity == 2
-        replys = gen_each_reply.call(read_loop(is_client: false), @req_view)
+        replys = gen_each_reply.call(
+          read_loop(set_input_stream_done, is_client: false),
+          @req_view)
       else
         fail 'Illegal arity of reply generator'
       end
@@ -99,22 +111,6 @@ module GRPC
     END_OF_READS = :end_of_reads
     END_OF_WRITES = :end_of_writes
 
-    # signals that bidi operation is complete
-    def notify_done
-      return unless @op_notifier
-      GRPC.logger.debug("bidi-notify-done: notifying  #{@op_notifier}")
-      @op_notifier.notify(self)
-    end
-
-    # signals that a bidi operation is complete (read + write)
-    def finished
-      @done_mutex.synchronize do
-        return unless @reads_complete && @writes_complete && !@complete
-        @call.close
-        @complete = true
-      end
-    end
-
     # performs a read using @call.run_batch, ensures metadata is set up
     def read_using_run_batch
       ops = { RECV_MESSAGE => nil }
@@ -127,7 +123,8 @@ module GRPC
       batch_result
     end
 
-    def write_loop(requests, is_client: true)
+    # set_output_stream_done is relevant on client-side
+    def write_loop(requests, is_client: true, set_output_stream_done: nil)
       GRPC.logger.debug('bidi-write-loop: starting')
       count = 0
       requests.each do |req|
@@ -151,23 +148,20 @@ module GRPC
         GRPC.logger.debug("bidi-write-loop: client sent #{count}, waiting")
         @call.run_batch(SEND_CLOSE_FROM_CLIENT => nil)
         GRPC.logger.debug('bidi-write-loop: done')
-        notify_done
-        @writes_complete = true
-        finished
       end
       GRPC.logger.debug('bidi-write-loop: finished')
     rescue StandardError => e
       GRPC.logger.warn('bidi-write-loop: failed')
       GRPC.logger.warn(e)
-      notify_done
-      @writes_complete = true
-      finished
       raise e
+    ensure
+      set_output_stream_done.call if is_client
     end
 
     # Provides an enumerator that yields results of remote reads
-    def read_loop(is_client: true)
+    def read_loop(set_input_stream_done, is_client: true)
       return enum_for(:read_loop,
+                      set_input_stream_done,
                       is_client: is_client) unless block_given?
       GRPC.logger.debug('bidi-read-loop: starting')
       begin
@@ -201,10 +195,10 @@ module GRPC
         GRPC.logger.warn('bidi: read-loop failed')
         GRPC.logger.warn(e)
         raise e
+      ensure
+        set_input_stream_done.call
       end
       GRPC.logger.debug('bidi-read-loop: finished')
-      @reads_complete = true
-      finished
       # Make sure that the write loop is done done before finishing the call.
       # Note that blocking is ok at this point because we've already received
       # a status

src/ruby/lib/grpc/generic/rpc_desc.rb

@@ -48,7 +48,7 @@ module GRPC
     end
 
     def handle_request_response(active_call, mth)
-      req = active_call.remote_read
+      req = active_call.read_unary_request
       resp = mth.call(req, active_call.single_req_view)
       active_call.server_unary_response(
         resp, trailing_metadata: active_call.output_metadata)
@@ -61,7 +61,7 @@ module GRPC
     end
 
     def handle_server_streamer(active_call, mth)
-      req = active_call.remote_read
+      req = active_call.read_unary_request
       replys = mth.call(req, active_call.single_req_view)
       replys.each { |r| active_call.remote_send(r) }
       send_status(active_call, OK, 'OK', active_call.output_metadata)

src/ruby/lib/grpc/generic/rpc_server.rb

@@ -418,6 +418,7 @@ module GRPC
                          metadata_received: true,
                          started: false,
                          metadata_to_send: connect_md)
+      c.attach_peer_cert(an_rpc.call.peer_cert)
       mth = an_rpc.method.to_sym
       [c, mth]
     end

src/ruby/spec/client_auth_spec.rb

@@ -0,0 +1,137 @@
+# Copyright 2015 gRPC authors.
+#
+# Licensed 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.
+
+require 'grpc'
+
+def create_channel_creds
+  test_root = File.join(File.dirname(__FILE__), 'testdata')
+  files = ['ca.pem', 'client.key', 'client.pem']
+  creds = files.map { |f| File.open(File.join(test_root, f)).read }
+  GRPC::Core::ChannelCredentials.new(creds[0], creds[1], creds[2])
+end
+
+def client_cert
+  test_root = File.join(File.dirname(__FILE__), 'testdata')
+  cert = File.open(File.join(test_root, 'client.pem')).read
+  fail unless cert.is_a?(String)
+  cert
+end
+
+def create_server_creds
+  test_root = File.join(File.dirname(__FILE__), 'testdata')
+  p "test root: #{test_root}"
+  files = ['ca.pem', 'server1.key', 'server1.pem']
+  creds = files.map { |f| File.open(File.join(test_root, f)).read }
+  GRPC::Core::ServerCredentials.new(
+    creds[0],
+    [{ private_key: creds[1], cert_chain: creds[2] }],
+    true) # force client auth
+end
+
+# A test message
+class EchoMsg
+  def self.marshal(_o)
+    ''
+  end
+
+  def self.unmarshal(_o)
+    EchoMsg.new
+  end
+end
+
+# a test service that checks the cert of its peer
+class SslTestService
+  include GRPC::GenericService
+  rpc :an_rpc, EchoMsg, EchoMsg
+  rpc :a_client_streaming_rpc, stream(EchoMsg), EchoMsg
+  rpc :a_server_streaming_rpc, EchoMsg, stream(EchoMsg)
+  rpc :a_bidi_rpc, stream(EchoMsg), stream(EchoMsg)
+
+  def check_peer_cert(call)
+    error_msg = "want:\n#{client_cert}\n\ngot:\n#{call.peer_cert}"
+    fail(error_msg) unless call.peer_cert == client_cert
+  end
+
+  def an_rpc(req, call)
+    check_peer_cert(call)
+    req
+  end
+
+  def a_client_streaming_rpc(call)
+    check_peer_cert(call)
+    call.each_remote_read.each { |r| p r }
+    EchoMsg.new
+  end
+
+  def a_server_streaming_rpc(_, call)
+    check_peer_cert(call)
+    [EchoMsg.new, EchoMsg.new]
+  end
+
+  def a_bidi_rpc(requests, call)
+    check_peer_cert(call)
+    requests.each { |r| p r }
+    [EchoMsg.new, EchoMsg.new]
+  end
+end
+
+SslTestServiceStub = SslTestService.rpc_stub_class
+
+describe 'client-server auth' do
+  RpcServer = GRPC::RpcServer
+
+  before(:all) do
+    server_opts = {
+      poll_period: 1
+    }
+    @srv = RpcServer.new(**server_opts)
+    port = @srv.add_http2_port('0.0.0.0:0', create_server_creds)
+    @srv.handle(SslTestService)
+    @srv_thd = Thread.new { @srv.run }
+    @srv.wait_till_running
+
+    client_opts = {
+      channel_args: {
+        GRPC::Core::Channel::SSL_TARGET => 'foo.test.google.fr'
+      }
+    }
+    @stub = SslTestServiceStub.new("localhost:#{port}",
+                                   create_channel_creds,
+                                   **client_opts)
+  end
+
+  after(:all) do
+    expect(@srv.stopped?).to be(false)
+    @srv.stop
+    @srv_thd.join
+  end
+
+  it 'client-server auth with unary RPCs' do
+    @stub.an_rpc(EchoMsg.new)
+  end
+
+  it 'client-server auth with client streaming RPCs' do
+    @stub.a_client_streaming_rpc([EchoMsg.new, EchoMsg.new])
+  end
+
+  it 'client-server auth with server streaming RPCs' do
+    responses = @stub.a_server_streaming_rpc(EchoMsg.new)
+    responses.each { |r| p r }
+  end
+
+  it 'client-server auth with bidi RPCs' do
+    responses = @stub.a_bidi_rpc([EchoMsg.new, EchoMsg.new])
+    responses.each { |r| p r }
+  end
+end

src/ruby/spec/generic/active_call_spec.rb

@@ -473,7 +473,7 @@ describe GRPC::ActiveCall do
       server_call.remote_send('server_response')
       expect(client_call.remote_read).to eq('server_response')
       server_call.send_status(OK, 'status code is OK')
-      expect { client_call.finished }.to_not raise_error
+      expect { client_call.receive_and_check_status }.to_not raise_error
     end
 
     it 'finishes ok if the server sends an early status response' do
@@ -490,7 +490,7 @@ describe GRPC::ActiveCall do
       expect do
         call.run_batch(CallOps::SEND_CLOSE_FROM_CLIENT => nil)
       end.to_not raise_error
-      expect { client_call.finished }.to_not raise_error
+      expect { client_call.receive_and_check_status }.to_not raise_error
     end
 
     it 'finishes ok if SEND_CLOSE and RECV_STATUS has been sent' do

src/ruby/spec/generic/client_stub_spec.rb

@@ -36,6 +36,53 @@ include GRPC::Core::StatusCodes
 include GRPC::Core::TimeConsts
 include GRPC::Core::CallOps
 
+# check that methods on a finished/closed call t crash
+def check_op_view_of_finished_client_call(op_view,
+                                          expected_metadata,
+                                          expected_trailing_metadata)
+  # use read_response_stream to try to iterate through
+  # possible response stream
+  fail('need something to attempt reads') unless block_given?
+  expect do
+    resp = op_view.execute
+    yield resp
+  end.to raise_error(GRPC::Core::CallError)
+
+  expect { op_view.start_call }.to raise_error(RuntimeError)
+
+  sanity_check_values_of_accessors(op_view,
+                                   expected_metadata,
+                                   expected_trailing_metadata)
+
+  expect do
+    op_view.wait
+    op_view.cancel
+    op_view.write_flag = 1
+  end.to_not raise_error
+end
+
+def sanity_check_values_of_accessors(op_view,
+                                     expected_metadata,
+                                     expected_trailing_metadata)
+  expected_status = Struct::Status.new
+  expected_status.code = 0
+  expected_status.details = 'OK'
+  expected_status.metadata = expected_trailing_metadata
+
+  expect(op_view.status).to eq(expected_status)
+  expect(op_view.metadata).to eq(expected_metadata)
+  expect(op_view.trailing_metadata).to eq(expected_trailing_metadata)
+
+  expect(op_view.cancelled?).to be(false)
+  expect(op_view.write_flag).to be(nil)
+
+  # The deadline attribute of a call can be either
+  # a GRPC::Core::TimeSpec or a Time, which are mutually exclusive.
+  # TODO: fix so that the accessor always returns the same type.
+  expect(op_view.deadline.is_a?(GRPC::Core::TimeSpec) ||
+         op_view.deadline.is_a?(Time)).to be(true)
+end
+
 describe 'ClientStub' do
   let(:noop) { proc { |x| x } }
 
@@ -45,6 +92,7 @@ describe 'ClientStub' do
     @method = 'an_rpc_method'
     @pass = OK
     @fail = INTERNAL
+    @metadata = { k1: 'v1', k2: 'v2' }
   end
 
   after(:each) do
@@ -107,7 +155,7 @@ describe 'ClientStub' do
     end
   end
 
-  describe '#request_response' do
+  describe '#request_response', request_response: true do
     before(:each) do
       @sent_msg, @resp = 'a_msg', 'a_reply'
     end
@@ -126,7 +174,7 @@ describe 'ClientStub' do
         server_port = create_test_server
         host = "localhost:#{server_port}"
         th = run_request_response(@sent_msg, @resp, @pass,
-                                  k1: 'v1', k2: 'v2')
+                                  expected_metadata: { k1: 'v1', k2: 'v2' })
         stub = GRPC::ClientStub.new(host, :this_channel_is_insecure)
         expect(get_response(stub)).to eq(@resp)
         th.join
@@ -187,13 +235,24 @@ describe 'ClientStub' do
         # Kill the server thread so tests can complete
         th.kill
       end
+
+      it 'should raise ArgumentError if metadata contains invalid values' do
+        @metadata.merge!(k3: 3)
+        server_port = create_test_server
+        host = "localhost:#{server_port}"
+        stub = GRPC::ClientStub.new(host, :this_channel_is_insecure)
+        expect do
+          get_response(stub)
+        end.to raise_error(ArgumentError,
+                           /Header values must be of type string or array/)
+      end
     end
 
     describe 'without a call operation' do
       def get_response(stub, credentials: nil)
         puts credentials.inspect
         stub.request_response(@method, @sent_msg, noop, noop,
-                              metadata: { k1: 'v1', k2: 'v2' },
+                              metadata: @metadata,
                               credentials: credentials)
       end
 
@@ -201,40 +260,62 @@ describe 'ClientStub' do
     end
 
     describe 'via a call operation' do
+      after(:each) do
+        # make sure op.wait doesn't hang, even if there's a bad status
+        @op.wait
+      end
       def get_response(stub, run_start_call_first: false, credentials: nil)
-        op = stub.request_response(@method, @sent_msg, noop, noop,
-                                   return_op: true,
-                                   metadata: { k1: 'v1', k2: 'v2' },
-                                   deadline: from_relative_time(2),
-                                   credentials: credentials)
-        expect(op).to be_a(GRPC::ActiveCall::Operation)
-        op.start_call if run_start_call_first
-        result = op.execute
-        op.wait # make sure wait doesn't hang
+        @op = stub.request_response(@method, @sent_msg, noop, noop,
+                                    return_op: true,
+                                    metadata: @metadata,
+                                    deadline: from_relative_time(2),
+                                    credentials: credentials)
+        expect(@op).to be_a(GRPC::ActiveCall::Operation)
+        @op.start_call if run_start_call_first
+        result = @op.execute
         result
       end
 
       it_behaves_like 'request response'
 
-      it 'sends metadata to the server ok when running start_call first' do
+      def run_op_view_metadata_test(run_start_call_first)
         server_port = create_test_server
         host = "localhost:#{server_port}"
-        th = run_request_response(@sent_msg, @resp, @pass,
-                                  k1: 'v1', k2: 'v2')
+
+        @server_initial_md = { 'sk1' => 'sv1', 'sk2' => 'sv2' }
+        @server_trailing_md = { 'tk1' => 'tv1', 'tk2' => 'tv2' }
+        th = run_request_response(
+          @sent_msg, @resp, @pass,
+          expected_metadata: @metadata,
+          server_initial_md: @server_initial_md,
+          server_trailing_md: @server_trailing_md)
         stub = GRPC::ClientStub.new(host, :this_channel_is_insecure)
-        expect(get_response(stub)).to eq(@resp)
+        expect(
+          get_response(stub,
+                       run_start_call_first: run_start_call_first)).to eq(@resp)
         th.join
       end
+
+      it 'sends metadata to the server ok when running start_call first' do
+        run_op_view_metadata_test(true)
+        check_op_view_of_finished_client_call(
+          @op, @server_initial_md, @server_trailing_md) { |r| p r }
+      end
+
+      it 'does not crash when used after the call has been finished' do
+        run_op_view_metadata_test(false)
+        check_op_view_of_finished_client_call(
+          @op, @server_initial_md, @server_trailing_md) { |r| p r }
+      end
     end
   end
 
-  describe '#client_streamer' do
+  describe '#client_streamer', client_streamer: true do
     before(:each) do
       Thread.abort_on_exception = true
       server_port = create_test_server
       host = "localhost:#{server_port}"
       @stub = GRPC::ClientStub.new(host, :this_channel_is_insecure)
-      @metadata = { k1: 'v1', k2: 'v2' }
       @sent_msgs = Array.new(3) { |i| 'msg_' + (i + 1).to_s }
       @resp = 'a_reply'
     end
@@ -247,7 +328,8 @@ describe 'ClientStub' do
       end
 
       it 'should send metadata to the server ok' do
-        th = run_client_streamer(@sent_msgs, @resp, @pass, **@metadata)
+        th = run_client_streamer(@sent_msgs, @resp, @pass,
+                                 expected_metadata: @metadata)
         expect(get_response(@stub)).to eq(@resp)
         th.join
       end
@@ -278,27 +360,50 @@ describe 'ClientStub' do
     end
 
     describe 'via a call operation' do
+      after(:each) do
+        # make sure op.wait doesn't hang, even if there's a bad status
+        @op.wait
+      end
       def get_response(stub, run_start_call_first: false)
-        op = stub.client_streamer(@method, @sent_msgs, noop, noop,
-                                  return_op: true, metadata: @metadata)
-        expect(op).to be_a(GRPC::ActiveCall::Operation)
-        op.start_call if run_start_call_first
-        result = op.execute
-        op.wait # make sure wait doesn't hang
+        @op = stub.client_streamer(@method, @sent_msgs, noop, noop,
+                                   return_op: true, metadata: @metadata)
+        expect(@op).to be_a(GRPC::ActiveCall::Operation)
+        @op.start_call if run_start_call_first
+        result = @op.execute
         result
       end
 
       it_behaves_like 'client streaming'
 
-      it 'sends metadata to the server ok when running start_call first' do
-        th = run_client_streamer(@sent_msgs, @resp, @pass, **@metadata)
-        expect(get_response(@stub, run_start_call_first: true)).to eq(@resp)
+      def run_op_view_metadata_test(run_start_call_first)
+        @server_initial_md = { 'sk1' => 'sv1', 'sk2' => 'sv2' }
+        @server_trailing_md = { 'tk1' => 'tv1', 'tk2' => 'tv2' }
+        th = run_client_streamer(
+          @sent_msgs, @resp, @pass,
+          expected_metadata: @metadata,
+          server_initial_md: @server_initial_md,
+          server_trailing_md: @server_trailing_md)
+        expect(
+          get_response(@stub,
+                       run_start_call_first: run_start_call_first)).to eq(@resp)
         th.join
       end
+
+      it 'sends metadata to the server ok when running start_call first' do
+        run_op_view_metadata_test(true)
+        check_op_view_of_finished_client_call(
+          @op, @server_initial_md, @server_trailing_md) { |r| p r }
+      end
+
+      it 'does not crash when used after the call has been finished' do
+        run_op_view_metadata_test(false)
+        check_op_view_of_finished_client_call(
+          @op, @server_initial_md, @server_trailing_md) { |r| p r }
+      end
     end
   end
 
-  describe '#server_streamer' do
+  describe '#server_streamer', server_streamer: true do
     before(:each) do
       @sent_msg = 'a_msg'
       @replys = Array.new(3) { |i| 'reply_' + (i + 1).to_s }
@@ -328,18 +433,42 @@ describe 'ClientStub' do
         server_port = create_test_server
         host = "localhost:#{server_port}"
         th = run_server_streamer(@sent_msg, @replys, @fail,
-                                 k1: 'v1', k2: 'v2')
+                                 expected_metadata: { k1: 'v1', k2: 'v2' })
         stub = GRPC::ClientStub.new(host, :this_channel_is_insecure)
         e = get_responses(stub)
         expect { e.collect { |r| r } }.to raise_error(GRPC::BadStatus)
         th.join
       end
+
+      it 'should raise ArgumentError if metadata contains invalid values' do
+        @metadata.merge!(k3: 3)
+        server_port = create_test_server
+        host = "localhost:#{server_port}"
+        stub = GRPC::ClientStub.new(host, :this_channel_is_insecure)
+        expect do
+          get_responses(stub)
+        end.to raise_error(ArgumentError,
+                           /Header values must be of type string or array/)
+      end
+
+      it 'the call terminates when there is an unmarshalling error' do
+        server_port = create_test_server
+        host = "localhost:#{server_port}"
+        th = run_server_streamer(@sent_msg, @replys, @pass)
+        stub = GRPC::ClientStub.new(host, :this_channel_is_insecure)
+
+        unmarshal = proc { fail(ArgumentError, 'test unmarshalling error') }
+        expect do
+          get_responses(stub, unmarshal: unmarshal).collect { |r| r }
+        end.to raise_error(ArgumentError, 'test unmarshalling error')
+        th.join
+      end
     end
 
     describe 'without a call operation' do
-      def get_responses(stub)
-        e = stub.server_streamer(@method, @sent_msg, noop, noop,
-                                 metadata: { k1: 'v1', k2: 'v2' })
+      def get_responses(stub, unmarshal: noop)
+        e = stub.server_streamer(@method, @sent_msg, noop, unmarshal,
+                                 metadata: @metadata)
         expect(e).to be_a(Enumerator)
         e
       end
@@ -351,10 +480,10 @@ describe 'ClientStub' do
       after(:each) do
         @op.wait # make sure wait doesn't hang
       end
-      def get_responses(stub, run_start_call_first: false)
-        @op = stub.server_streamer(@method, @sent_msg, noop, noop,
+      def get_responses(stub, run_start_call_first: false, unmarshal: noop)
+        @op = stub.server_streamer(@method, @sent_msg, noop, unmarshal,
                                    return_op: true,
-                                   metadata: { k1: 'v1', k2: 'v2' })
+                                   metadata: @metadata)
         expect(@op).to be_a(GRPC::ActiveCall::Operation)
         @op.start_call if run_start_call_first
         e = @op.execute
@@ -364,20 +493,41 @@ describe 'ClientStub' do
 
       it_behaves_like 'server streaming'
 
-      it 'should send metadata to the server ok when start_call is run first' do
+      def run_op_view_metadata_test(run_start_call_first)
         server_port = create_test_server
         host = "localhost:#{server_port}"
-        th = run_server_streamer(@sent_msg, @replys, @fail,
-                                 k1: 'v1', k2: 'v2')
+        @server_initial_md = { 'sk1' => 'sv1', 'sk2' => 'sv2' }
+        @server_trailing_md = { 'tk1' => 'tv1', 'tk2' => 'tv2' }
+        th = run_server_streamer(
+          @sent_msg, @replys, @pass,
+          expected_metadata: @metadata,
+          server_initial_md: @server_initial_md,
+          server_trailing_md: @server_trailing_md)
         stub = GRPC::ClientStub.new(host, :this_channel_is_insecure)
-        e = get_responses(stub, run_start_call_first: true)
-        expect { e.collect { |r| r } }.to raise_error(GRPC::BadStatus)
+        e = get_responses(stub, run_start_call_first: run_start_call_first)
+        expect(e.collect { |r| r }).to eq(@replys)
         th.join
       end
+
+      it 'should send metadata to the server ok when start_call is run first' do
+        run_op_view_metadata_test(true)
+        check_op_view_of_finished_client_call(
+          @op, @server_initial_md, @server_trailing_md) do |responses|
+          responses.each { |r| p r }
+        end
+      end
+
+      it 'does not crash when used after the call has been finished' do
+        run_op_view_metadata_test(false)
+        check_op_view_of_finished_client_call(
+          @op, @server_initial_md, @server_trailing_md) do |responses|
+          responses.each { |r| p r }
+        end
+      end
     end
   end
 
-  describe '#bidi_streamer' do
+  describe '#bidi_streamer', bidi: true do
     before(:each) do
       @sent_msgs = Array.new(3) { |i| 'msg_' + (i + 1).to_s }
       @replys = Array.new(3) { |i| 'reply_' + (i + 1).to_s }
@@ -386,7 +536,7 @@ describe 'ClientStub' do
     end
 
     shared_examples 'bidi streaming' do
-      it 'supports sending all the requests first', bidi: true do
+      it 'supports sending all the requests first' do
         th = run_bidi_streamer_handle_inputs_first(@sent_msgs, @replys,
                                                    @pass)
         stub = GRPC::ClientStub.new(@host, :this_channel_is_insecure)
@@ -395,7 +545,7 @@ describe 'ClientStub' do
         th.join
       end
 
-      it 'supports client-initiated ping pong', bidi: true do
+      it 'supports client-initiated ping pong' do
         th = run_bidi_streamer_echo_ping_pong(@sent_msgs, @pass, true)
         stub = GRPC::ClientStub.new(@host, :this_channel_is_insecure)
         e = get_responses(stub)
@@ -403,18 +553,39 @@ describe 'ClientStub' do
         th.join
       end
 
-      it 'supports a server-initiated ping pong', bidi: true do
+      it 'supports a server-initiated ping pong' do
         th = run_bidi_streamer_echo_ping_pong(@sent_msgs, @pass, false)
         stub = GRPC::ClientStub.new(@host, :this_channel_is_insecure)
         e = get_responses(stub)
         expect(e.collect { |r| r }).to eq(@sent_msgs)
         th.join
       end
+
+      it 'should raise an error if the status is not ok' do
+        th = run_bidi_streamer_echo_ping_pong(@sent_msgs, @fail, false)
+        stub = GRPC::ClientStub.new(@host, :this_channel_is_insecure)
+        e = get_responses(stub)
+        expect { e.collect { |r| r } }.to raise_error(GRPC::BadStatus)
+        th.join
+      end
+
+      # TODO: add test for metadata-related ArgumentError in a bidi call once
+      # issue mentioned in https://github.com/grpc/grpc/issues/10526 is fixed
+
+      it 'should send metadata to the server ok' do
+        th = run_bidi_streamer_echo_ping_pong(@sent_msgs, @pass, true,
+                                              expected_metadata: @metadata)
+        stub = GRPC::ClientStub.new(@host, :this_channel_is_insecure)
+        e = get_responses(stub)
+        expect(e.collect { |r| r }).to eq(@sent_msgs)
+        th.join
+      end
     end
 
     describe 'without a call operation' do
       def get_responses(stub)
-        e = stub.bidi_streamer(@method, @sent_msgs, noop, noop)
+        e = stub.bidi_streamer(@method, @sent_msgs, noop, noop,
+                               metadata: @metadata)
         expect(e).to be_a(Enumerator)
         e
       end
@@ -428,7 +599,8 @@ describe 'ClientStub' do
       end
       def get_responses(stub, run_start_call_first: false)
         @op = stub.bidi_streamer(@method, @sent_msgs, noop, noop,
-                                 return_op: true)
+                                 return_op: true,
+                                 metadata: @metadata)
         expect(@op).to be_a(GRPC::ActiveCall::Operation)
         @op.start_call if run_start_call_first
         e = @op.execute
@@ -438,27 +610,53 @@ describe 'ClientStub' do
 
       it_behaves_like 'bidi streaming'
 
-      it 'can run start_call before executing the call' do
-        th = run_bidi_streamer_handle_inputs_first(@sent_msgs, @replys,
-                                                   @pass)
+      def run_op_view_metadata_test(run_start_call_first)
+        @server_initial_md = { 'sk1' => 'sv1', 'sk2' => 'sv2' }
+        @server_trailing_md = { 'tk1' => 'tv1', 'tk2' => 'tv2' }
+        th = run_bidi_streamer_echo_ping_pong(
+          @sent_msgs, @pass, true,
+          expected_metadata: @metadata,
+          server_initial_md: @server_initial_md,
+          server_trailing_md: @server_trailing_md)
         stub = GRPC::ClientStub.new(@host, :this_channel_is_insecure)
-        e = get_responses(stub, run_start_call_first: true)
-        expect(e.collect { |r| r }).to eq(@replys)
+        e = get_responses(stub, run_start_call_first: run_start_call_first)
+        expect(e.collect { |r| r }).to eq(@sent_msgs)
         th.join
       end
+
+      it 'can run start_call before executing the call' do
+        run_op_view_metadata_test(true)
+        check_op_view_of_finished_client_call(
+          @op, @server_initial_md, @server_trailing_md) do |responses|
+          responses.each { |r| p r }
+        end
+      end
+
+      it 'doesnt crash when op_view used after call has finished' do
+        run_op_view_metadata_test(false)
+        check_op_view_of_finished_client_call(
+          @op, @server_initial_md, @server_trailing_md) do |responses|
+          responses.each { |r| p r }
+        end
+      end
     end
   end
 
-  def run_server_streamer(expected_input, replys, status, **kw)
-    wanted_metadata = kw.clone
+  def run_server_streamer(expected_input, replys, status,
+                          expected_metadata: {},
+                          server_initial_md: {},
+                          server_trailing_md: {})
+    wanted_metadata = expected_metadata.clone
     wakey_thread do |notifier|
-      c = expect_server_to_be_invoked(notifier)
+      c = expect_server_to_be_invoked(
+        notifier, metadata_to_send: server_initial_md)
       wanted_metadata.each do |k, v|
         expect(c.metadata[k.to_s]).to eq(v)
       end
       expect(c.remote_read).to eq(expected_input)
       replys.each { |r| c.remote_send(r) }
-      c.send_status(status, status == @pass ? 'OK' : 'NOK', true)
+      c.send_status(status, status == @pass ? 'OK' : 'NOK', true,
+                    metadata: server_trailing_md)
     end
   end
 
@@ -472,9 +670,17 @@ describe 'ClientStub' do
     end
   end
 
-  def run_bidi_streamer_echo_ping_pong(expected_inputs, status, client_starts)
+  def run_bidi_streamer_echo_ping_pong(expected_inputs, status, client_starts,
+                                       expected_metadata: {},
+                                       server_initial_md: {},
+                                       server_trailing_md: {})
+    wanted_metadata = expected_metadata.clone
     wakey_thread do |notifier|
-      c = expect_server_to_be_invoked(notifier)
+      c = expect_server_to_be_invoked(
+        notifier, metadata_to_send: server_initial_md)
+      wanted_metadata.each do |k, v|
+        expect(c.metadata[k.to_s]).to eq(v)
+      end
       expected_inputs.each do |i|
         if client_starts
           expect(c.remote_read).to eq(i)
@@ -484,33 +690,44 @@ describe 'ClientStub' do
           expect(c.remote_read).to eq(i)
         end
       end
-      c.send_status(status, status == @pass ? 'OK' : 'NOK', true)
+      c.send_status(status, status == @pass ? 'OK' : 'NOK', true,
+                    metadata: server_trailing_md)
     end
   end
 
-  def run_client_streamer(expected_inputs, resp, status, **kw)
-    wanted_metadata = kw.clone
+  def run_client_streamer(expected_inputs, resp, status,
+                          expected_metadata: {},
+                          server_initial_md: {},
+                          server_trailing_md: {})
+    wanted_metadata = expected_metadata.clone
     wakey_thread do |notifier|
-      c = expect_server_to_be_invoked(notifier)
+      c = expect_server_to_be_invoked(
+        notifier, metadata_to_send: server_initial_md)
       expected_inputs.each { |i| expect(c.remote_read).to eq(i) }
       wanted_metadata.each do |k, v|
         expect(c.metadata[k.to_s]).to eq(v)
       end
       c.remote_send(resp)
-      c.send_status(status, status == @pass ? 'OK' : 'NOK', true)
+      c.send_status(status, status == @pass ? 'OK' : 'NOK', true,
+                    metadata: server_trailing_md)
     end
   end
 
-  def run_request_response(expected_input, resp, status, **kw)
-    wanted_metadata = kw.clone
+  def run_request_response(expected_input, resp, status,
+                           expected_metadata: {},
+                           server_initial_md: {},
+                           server_trailing_md: {})
+    wanted_metadata = expected_metadata.clone
     wakey_thread do |notifier|
-      c = expect_server_to_be_invoked(notifier)
+      c = expect_server_to_be_invoked(
+        notifier, metadata_to_send: server_initial_md)
       expect(c.remote_read).to eq(expected_input)
       wanted_metadata.each do |k, v|
         expect(c.metadata[k.to_s]).to eq(v)
       end
       c.remote_send(resp)
-      c.send_status(status, status == @pass ? 'OK' : 'NOK', true)
+      c.send_status(status, status == @pass ? 'OK' : 'NOK', true,
+                    metadata: server_trailing_md)
     end
   end
 
@@ -528,13 +745,13 @@ describe 'ClientStub' do
     @server.add_http2_port('0.0.0.0:0', :this_port_is_insecure)
   end
 
-  def expect_server_to_be_invoked(notifier)
+  def expect_server_to_be_invoked(notifier, metadata_to_send: nil)
     @server.start
     notifier.notify(nil)
     recvd_rpc = @server.request_call
     recvd_call = recvd_rpc.call
     recvd_call.metadata = recvd_rpc.metadata
-    recvd_call.run_batch(SEND_INITIAL_METADATA => nil)
+    recvd_call.run_batch(SEND_INITIAL_METADATA => metadata_to_send)
     GRPC::ActiveCall.new(recvd_call, noop, noop, INFINITE_FUTURE,
                          metadata_received: true)
   end

src/ruby/spec/generic/rpc_desc_spec.rb

@@ -38,14 +38,14 @@ describe GRPC::RpcDesc do
 
   shared_examples 'it handles errors' do
     it 'sends the specified status if BadStatus is raised' do
-      expect(@call).to receive(:remote_read).once.and_return(Object.new)
+      expect(@call).to receive(:read_unary_request).once.and_return(Object.new)
       expect(@call).to receive(:send_status).once.with(@bs_code, 'NOK', false,
                                                        metadata: {})
       this_desc.run_server_method(@call, method(:bad_status))
     end
 
     it 'sends status UNKNOWN if other StandardErrors are raised' do
-      expect(@call).to receive(:remote_read).once.and_return(Object.new)
+      expect(@call).to receive(:read_unary_request).once.and_return(Object.new)
       expect(@call).to receive(:send_status).once.with(UNKNOWN,
                                                        arg_error_msg,
                                                        false, metadata: {})
@@ -53,7 +53,7 @@ describe GRPC::RpcDesc do
     end
 
     it 'absorbs CallError with no further action' do
-      expect(@call).to receive(:remote_read).once.and_raise(CallError)
+      expect(@call).to receive(:read_unary_request).once.and_raise(CallError)
       blk = proc do
         this_desc.run_server_method(@call, method(:fake_reqresp))
       end
@@ -75,7 +75,7 @@ describe GRPC::RpcDesc do
 
       it 'sends a response and closes the stream if there no errors' do
         req = Object.new
-        expect(@call).to receive(:remote_read).once.and_return(req)
+        expect(@call).to receive(:read_unary_request).once.and_return(req)
         expect(@call).to receive(:output_metadata).once.and_return(fake_md)
         expect(@call).to receive(:server_unary_response).once
           .with(@ok_response, trailing_metadata: fake_md)
@@ -133,7 +133,7 @@ describe GRPC::RpcDesc do
 
       it 'sends a response and closes the stream if there no errors' do
         req = Object.new
-        expect(@call).to receive(:remote_read).once.and_return(req)
+        expect(@call).to receive(:read_unary_request).once.and_return(req)
         expect(@call).to receive(:remote_send).twice.with(@ok_response)
         expect(@call).to receive(:output_metadata).and_return(fake_md)
         expect(@call).to receive(:send_status).once.with(OK, 'OK', true,

src/ruby/spec/generic/rpc_server_spec.rb

@@ -111,6 +111,47 @@ end
 
 SlowStub = SlowService.rpc_stub_class
 
+# a test service that hangs onto call objects
+# and uses them after the server-side call has been
+# finished
+class CheckCallAfterFinishedService
+  include GRPC::GenericService
+  rpc :an_rpc, EchoMsg, EchoMsg
+  rpc :a_client_streaming_rpc, stream(EchoMsg), EchoMsg
+  rpc :a_server_streaming_rpc, EchoMsg, stream(EchoMsg)
+  rpc :a_bidi_rpc, stream(EchoMsg), stream(EchoMsg)
+  attr_reader :server_side_call
+
+  def an_rpc(req, call)
+    fail 'shouldnt reuse service' unless @server_side_call.nil?
+    @server_side_call = call
+    req
+  end
+
+  def a_client_streaming_rpc(call)
+    fail 'shouldnt reuse service' unless @server_side_call.nil?
+    @server_side_call = call
+    # iterate through requests so call can complete
+    call.each_remote_read.each { |r| p r }
+    EchoMsg.new
+  end
+
+  def a_server_streaming_rpc(_, call)
+    fail 'shouldnt reuse service' unless @server_side_call.nil?
+    @server_side_call = call
+    [EchoMsg.new, EchoMsg.new]
+  end
+
+  def a_bidi_rpc(requests, call)
+    fail 'shouldnt reuse service' unless @server_side_call.nil?
+    @server_side_call = call
+    requests.each { |r| p r }
+    [EchoMsg.new, EchoMsg.new]
+  end
+end
+
+CheckCallAfterFinishedServiceStub = CheckCallAfterFinishedService.rpc_stub_class
+
 describe GRPC::RpcServer do
   RpcServer = GRPC::RpcServer
   StatusCodes = GRPC::Core::StatusCodes
@@ -505,5 +546,109 @@ describe GRPC::RpcServer do
         t.join
       end
     end
+
+    context 'when call objects are used after calls have completed' do
+      before(:each) do
+        server_opts = {
+          poll_period: 1
+        }
+        @srv = RpcServer.new(**server_opts)
+        alt_port = @srv.add_http2_port('0.0.0.0:0', :this_port_is_insecure)
+        @alt_host = "0.0.0.0:#{alt_port}"
+
+        @service = CheckCallAfterFinishedService.new
+        @srv.handle(@service)
+        @srv_thd  = Thread.new { @srv.run }
+        @srv.wait_till_running
+      end
+
+      # check that the server-side call is still in a usable state even
+      # after it has finished
+      def check_single_req_view_of_finished_call(call)
+        common_check_of_finished_server_call(call)
+
+        expect(call.peer).to be_a(String)
+        expect(call.peer_cert).to be(nil)
+      end
+
+      def check_multi_req_view_of_finished_call(call)
+        common_check_of_finished_server_call(call)
+
+        expect do
+          call.each_remote_read.each { |r| p r }
+        end.to raise_error(GRPC::Core::CallError)
+      end
+
+      def common_check_of_finished_server_call(call)
+        expect do
+          call.merge_metadata_to_send({})
+        end.to raise_error(RuntimeError)
+
+        expect do
+          call.send_initial_metadata
+        end.to_not raise_error
+
+        expect(call.cancelled?).to be(false)
+        expect(call.metadata).to be_a(Hash)
+        expect(call.metadata['user-agent']).to be_a(String)
+
+        expect(call.metadata_sent).to be(true)
+        expect(call.output_metadata).to eq({})
+        expect(call.metadata_to_send).to eq({})
+        expect(call.deadline.is_a?(Time)).to be(true)
+      end
+
+      it 'should not crash when call used after an unary call is finished' do
+        req = EchoMsg.new
+        stub = CheckCallAfterFinishedServiceStub.new(@alt_host,
+                                                     :this_channel_is_insecure)
+        resp = stub.an_rpc(req)
+        expect(resp).to be_a(EchoMsg)
+        @srv.stop
+        @srv_thd.join
+
+        check_single_req_view_of_finished_call(@service.server_side_call)
+      end
+
+      it 'should not crash when call used after client streaming finished' do
+        requests = [EchoMsg.new, EchoMsg.new]
+        stub = CheckCallAfterFinishedServiceStub.new(@alt_host,
+                                                     :this_channel_is_insecure)
+        resp = stub.a_client_streaming_rpc(requests)
+        expect(resp).to be_a(EchoMsg)
+        @srv.stop
+        @srv_thd.join
+
+        check_multi_req_view_of_finished_call(@service.server_side_call)
+      end
+
+      it 'should not crash when call used after server streaming finished' do
+        req = EchoMsg.new
+        stub = CheckCallAfterFinishedServiceStub.new(@alt_host,
+                                                     :this_channel_is_insecure)
+        responses = stub.a_server_streaming_rpc(req)
+        responses.each do |r|
+          expect(r).to be_a(EchoMsg)
+        end
+        @srv.stop
+        @srv_thd.join
+
+        check_single_req_view_of_finished_call(@service.server_side_call)
+      end
+
+      it 'should not crash when call used after a bidi call is finished' do
+        requests = [EchoMsg.new, EchoMsg.new]
+        stub = CheckCallAfterFinishedServiceStub.new(@alt_host,
+                                                     :this_channel_is_insecure)
+        responses = stub.a_bidi_rpc(requests)
+        responses.each do |r|
+          expect(r).to be_a(EchoMsg)
+        end
+        @srv.stop
+        @srv_thd.join
+
+        check_multi_req_view_of_finished_call(@service.server_side_call)
+      end
+    end
   end
 end

src/ruby/spec/testdata/client.key

@@ -0,0 +1,16 @@
+-----BEGIN PRIVATE KEY-----
+MIICeQIBADANBgkqhkiG9w0BAQEFAASCAmMwggJfAgEAAoGBAOxUR9uhvhbeVUIM
+s5WbH0px0mehl2+6sZpNjzvE2KimZpHzMJHukVH0Ffkvhs0b8+S5Ut9VNUAqd3IM
+JCCAEGtRNoQhM1t9Yr2zAckSvbRacp+FL/Cj9eDmyo00KsVGaeefA4Dh4OW+ZhkT
+NKcldXqkSuj1sEf244JZYuqZp6/tAgMBAAECgYEAi2NSVqpZMafE5YYUTcMGe6QS
+k2jtpsqYgggI2RnLJ/2tNZwYI5pwP8QVSbnMaiF4gokD5hGdrNDfTnb2v+yIwYEH
+0w8+oG7Z81KodsiZSIDJfTGsAZhVNwOz9y0VD8BBZZ1/274Zh52AUKLjZS/ZwIbS
+W2ywya855dPnH/wj+0ECQQD9X8D920kByTNHhBG18biAEZ4pxs9f0OAG8333eVcI
+w2lJDLsYDZrCB2ocgA3lUdozlzPC7YDYw8reg0tkiRY5AkEA7sdNzOeQsQRn7++5
+0bP9DtT/iON1gbfxRzCfCfXdoOtfQWIzTePWtURt9X/5D9NofI0Rg5W2oGy/MLe5
+/sXHVQJBAIup5XrJDkQywNZyAUU2ecn2bCWBFjwtqd+LBmuMciI9fOKsZtEKZrz/
+U0lkeMRoSwvXE8wmGLjjrAbdfohrXFkCQQDZEx/LtIl6JINJQiswVe0tWr6k+ASP
+1WXoTm+HYpoF/XUvv9LccNF1IazFj34hwRQwhx7w/V52Ieb+p0jUMYGxAkEAjDhd
+9pBO1fKXWiXzi9ZKfoyTNcUq3eBSVKwPG2nItg5ycXengjT5sgcWDnciIzW7BIVI
+JiqOszq9GWESErAatg==
+-----END PRIVATE KEY-----

src/ruby/spec/testdata/client.pem

@@ -0,0 +1,14 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----