clang-format plus helpful comments

test/cpp/qps/client.h

@@ -69,7 +69,9 @@ typedef std::chrono::time_point<grpc_time_source> grpc_time;
 class Client {
  public:
   explicit Client(const ClientConfig& config)
-    : channels_(config.client_channels()), timer_(new Timer), interarrival_timer_() {
+      : channels_(config.client_channels()),
+        timer_(new Timer),
+        interarrival_timer_() {
     for (int i = 0; i < config.client_channels(); i++) {
       channels_[i].init(config.server_targets(i % config.server_targets_size()),
                         config);
@@ -110,14 +112,21 @@ class Client {
    public:
     ClientChannelInfo() {}
     ClientChannelInfo(const ClientChannelInfo& i) : channel_(), stub_() {
+      // The copy constructor is to satisfy old compilers
+      // that need it for using std::vector . It is only ever
+      // used for empty entries
       GPR_ASSERT(!i.channel_ && !i.stub_);
     }
     void init(const grpc::string& target, const ClientConfig& config) {
+      // We have to use a 2-phase init like this with a default
+      // constructor followed by an initializer function to make
+      // old compilers happy with using this in std::vector
       channel_ = CreateTestChannel(target, config.enable_ssl());
       stub_ = TestService::NewStub(channel_);
     }
     ChannelInterface* get_channel() { return channel_.get(); }
     TestService::Stub* get_stub() { return stub_.get(); }
+
    private:
     std::shared_ptr<ChannelInterface> channel_;
     std::unique_ptr<TestService::Stub> stub_;

test/cpp/qps/client_async.cc

@@ -337,7 +337,8 @@ class AsyncClient : public Client {
   std::vector<boolean> issue_allowed_;  // may this thread attempt to issue
   std::vector<grpc_time> next_issue_;   // when should it issue?
 
-  std::mutex *channel_lock_; // a vector, but avoid std::vector for old compilers
+  std::mutex*
+      channel_lock_;  // a vector, but avoid std::vector for old compilers
   std::vector<context_list> contexts_;  // per-channel list of idle contexts
   int max_outstanding_per_channel_;
   int channel_count_;

test/cpp/qps/client_sync.cc

@@ -125,7 +125,8 @@ class SynchronousStreamingClient GRPC_FINAL : public SynchronousClient {
   }
   ~SynchronousStreamingClient() {
     EndThreads();
-    for (auto stream = &stream_[0]; stream != &stream_[num_threads_]; stream++) {
+    for (auto stream = &stream_[0]; stream != &stream_[num_threads_];
+         stream++) {
       if (*stream) {
         (*stream)->WritesDone();
         EXPECT_TRUE((*stream)->Finish().ok());
@@ -150,8 +151,8 @@ class SynchronousStreamingClient GRPC_FINAL : public SynchronousClient {
   // These are both conceptually std::vector but cannot be for old compilers
   // that expect contained classes to support copy constructors
   grpc::ClientContext* context_;
-  std::unique_ptr<
+  std::unique_ptr<grpc::ClientReaderWriter<SimpleRequest, SimpleResponse>>*
-      grpc::ClientReaderWriter<SimpleRequest, SimpleResponse>>* stream_;
+      stream_;
 };
 
 std::unique_ptr<Client> CreateSynchronousUnaryClient(

test/cpp/qps/driver.cc

@@ -79,6 +79,7 @@ static deque<string> get_hosts(const string& name) {
 
 // Namespace for classes and functions used only in RunScenario
 // Using this rather than local definitions to workaround gcc-4.4 limitations
+// regarding using templates without linkage
 namespace runsc {
 
 // ClientContext allocator
@@ -149,6 +150,8 @@ std::unique_ptr<ScenarioResult> RunScenario(
 
   // Start servers
   using runsc::ServerData;
+  // servers is array rather than std::vector to avoid gcc-4.4 issues
+  // where class contained in std::vector must have a copy constructor
   ServerData servers[num_servers];
   for (size_t i = 0; i < num_servers; i++) {
     servers[i].stub = std::move(Worker::NewStub(
@@ -157,7 +160,8 @@ std::unique_ptr<ScenarioResult> RunScenario(
     result_server_config = server_config;
     result_server_config.set_host(workers[i]);
     *args.mutable_setup() = server_config;
-    servers[i].stream = std::move(servers[i].stub->RunServer(runsc::AllocContext(&contexts)));
+    servers[i].stream =
+        std::move(servers[i].stub->RunServer(runsc::AllocContext(&contexts)));
     GPR_ASSERT(servers[i].stream->Write(args));
     ServerStatus init_status;
     GPR_ASSERT(servers[i].stream->Read(&init_status));
@@ -174,6 +178,8 @@ std::unique_ptr<ScenarioResult> RunScenario(
 
   // Start clients
   using runsc::ClientData;
+  // clients is array rather than std::vector to avoid gcc-4.4 issues
+  // where class contained in std::vector must have a copy constructor
   ClientData clients[num_clients];
   for (size_t i = 0; i < num_clients; i++) {
     clients[i].stub = std::move(Worker::NewStub(CreateChannel(
@@ -182,7 +188,8 @@ std::unique_ptr<ScenarioResult> RunScenario(
     result_client_config = client_config;
     result_client_config.set_host(workers[i + num_servers]);
     *args.mutable_setup() = client_config;
-    clients[i].stream = std::move(clients[i].stub->RunTest(runsc::AllocContext(&contexts)));
+    clients[i].stream =
+        std::move(clients[i].stub->RunTest(runsc::AllocContext(&contexts)));
     GPR_ASSERT(clients[i].stream->Write(args));
     ClientStatus init_status;
     GPR_ASSERT(clients[i].stream->Read(&init_status));
@@ -217,6 +224,8 @@ std::unique_ptr<ScenarioResult> RunScenario(
 
   // Wait some time
   gpr_log(GPR_INFO, "Running");
+  // Use gpr_sleep_until rather than this_thread::sleep_until to support
+  // compilers that don't work with this_thread
   gpr_sleep_until(gpr_time_add(
       start, gpr_time_from_seconds(benchmark_seconds, GPR_TIMESPAN)));