TabManager: Set OOM scores via a new debugd interface on ChromeOS.

chromeos/dbus/debug_daemon_client.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chromeos/dbus/debug_daemon_client.h"
 
 #include <fcntl.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <unistd.h>
@@ skipping 442 matching lines @@
         base::Bind(&DebugDaemonClientImpl::OnRemoveRootfsVerification,
                    weak_ptr_factory_.GetWeakPtr(),
                    callback));
   }
 
   void WaitForServiceToBeAvailable(
       const WaitForServiceToBeAvailableCallback& callback) override {
     debugdaemon_proxy_->WaitForServiceToBeAvailable(callback);
   }
 
+  void SetOomScoreAdj(const std::map<int, int>& scores,
+                      const SetOomScoreAdjCallback& callback) override {
+    dbus::MethodCall method_call(debugd::kDebugdInterface,
+                                 debugd::kSetOomScoreAdj);
+    dbus::MessageWriter writer(&method_call);
+    dbus::MessageWriter sub_writer(NULL);

[hashimoto, 2016/08/15 03:54:23]

Please declare this variable in as local a scope as possible, and as close to
the first use as possible.
(https://google.github.io/styleguide/cppguide.html#Local_Variables)

Also, please use nullptr.

[cylee1, 2016/08/16 19:47:10]

Done.

+    dbus::MessageWriter elem_writer(NULL);

[hashimoto, 2016/08/15 03:54:23]

ditto.

[cylee1, 2016/08/16 19:47:10]

Done.

+
+    writer.OpenArray("{ii}", &sub_writer);
+    for (const auto& entry : scores) {
+      sub_writer.OpenDictEntry(&elem_writer);
+      elem_writer.AppendInt32(entry.first);
+      elem_writer.AppendInt32(entry.second);
+      sub_writer.CloseContainer(&elem_writer);
+    }
+    writer.CloseContainer(&sub_writer);
+
+    debugdaemon_proxy_->CallMethod(
+        &method_call,
+        dbus::ObjectProxy::TIMEOUT_USE_DEFAULT,
+        base::Bind(&DebugDaemonClientImpl::OnSetOomScoreAdj,
+                   weak_ptr_factory_.GetWeakPtr(),
+                   callback));
+  }
+
  protected:
   void Init(dbus::Bus* bus) override {
     debugdaemon_proxy_ =
         bus->GetObjectProxy(debugd::kDebugdServiceName,
                             dbus::ObjectPath(debugd::kDebugdServicePath));
   }
 
  private:
   // Called when a CheckValidity response is received.
   void OnCheckValidityGetDebugLogs(bool is_compressed,
@@ skipping 240 matching lines @@
 
   // Called when pipe i/o completes; pass data on and delete the instance.
   void OnIOComplete() {
     std::string pipe_data;
     pipe_reader_->GetData(&pipe_data);
     callback_.Run(GetTracingAgentName(), GetTraceEventLabel(),
                   base::RefCountedString::TakeString(&pipe_data));
     pipe_reader_.reset();
   }
 
+  void OnSetOomScoreAdj(const SetOomScoreAdjCallback& callback,
+                        dbus::Response* response) {
+    if (callback.is_null())

[hashimoto, 2016/08/15 03:54:23]

Is there any strong reason to allow null callbacks?
If not, please remove this code.

[cylee1, 2016/08/16 19:47:10]

Done.

+      return;
+
+    std::string output;
+    if (response && dbus::MessageReader(response).PopString(&output))
+      callback.Run(true, output);
+    else
+      callback.Run(false, "");
+  }
+
   dbus::ObjectProxy* debugdaemon_proxy_;
   std::unique_ptr<PipeReaderForString> pipe_reader_;
   StopAgentTracingCallback callback_;
   scoped_refptr<base::TaskRunner> stop_agent_tracing_task_runner_;
   base::WeakPtrFactory<DebugDaemonClientImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DebugDaemonClientImpl);
 };
 
 DebugDaemonClient::DebugDaemonClient() {
 }
 
 DebugDaemonClient::~DebugDaemonClient() {
 }
 
 // static
 DebugDaemonClient::StopAgentTracingCallback
 DebugDaemonClient::EmptyStopAgentTracingCallback() {
   return base::Bind(&EmptyStopAgentTracingCallbackBody);
 }
 
 // static
 DebugDaemonClient* DebugDaemonClient::Create() {
   return new DebugDaemonClientImpl();
 }
 
 }  // namespace chromeos