De-client tracing.TraceController interface

services/tracing/main.cc

 // Copyright 2014 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 "base/bind.h"
 #include "mojo/application/application_runner_chromium.h"
 #include "mojo/common/weak_binding_set.h"
+#include "mojo/common/weak_interface_ptr_set.h"
 #include "mojo/public/c/system/main.h"
 #include "mojo/public/cpp/application/application_delegate.h"
 #include "mojo/public/cpp/application/application_impl.h"
 #include "services/tracing/trace_data_sink.h"
 #include "services/tracing/tracing.mojom.h"
 
 namespace tracing {
 
 class TracingApp : public mojo::ApplicationDelegate,
                    public mojo::InterfaceFactory<TraceCoordinator>,
                    public tracing::TraceCoordinator,
-                   public mojo::InterfaceFactory<TraceDataCollector>,
                    public tracing::TraceDataCollector {
  public:
   TracingApp() {}
   ~TracingApp() override {}
 
  private:
   // mojo::ApplicationDelegate implementation.
   bool ConfigureIncomingConnection(
       mojo::ApplicationConnection* connection) override {
     connection->AddService<TraceCoordinator>(this);
-    connection->AddService<TraceDataCollector>(this);
+
+    // If someone connects to us they may want to use the TraceCoordinator
+    // interface and/or they may want to expose themselves to be traced. Attempt
+    // to connect to the TraceController interface to see if the application
+    // connecting to us wants to be traced. They can refuse the connection or
+    // close the pipe if not.
+    mojo::InterfacePtr<TraceController> controller_ptr;
+    connection->ConnectToService(&controller_ptr);
+    controller_ptrs_.AddInterfacePtr(controller_ptr.Pass());
     return true;
   }
 
   // mojo::InterfaceFactory<TraceCoordinator> implementation.
   void Create(mojo::ApplicationConnection* connection,
               mojo::InterfaceRequest<TraceCoordinator> request) override {
     coordinator_bindings_.AddBinding(this, request.Pass());
   }
 
-  // mojo::InterfaceFactory<TraceDataCollector> implementation.
-  void Create(mojo::ApplicationConnection* connection,
-              mojo::InterfaceRequest<TraceDataCollector> request) override {
-    collector_bindings_.AddBinding(this, request.Pass());
-  }
-
   // tracing::TraceCoordinator implementation.
   void Start(const mojo::String& base_name,
              const mojo::String& categories) override {
     base::FilePath base_name_path =
         base::FilePath::FromUTF8Unsafe(base_name.To<std::string>());
     sink_.reset(new TraceDataSink(base_name_path));
-    collector_bindings_.ForAllBindings([categories](
-        TraceController* controller) { controller->StartTracing(categories); });
+    controller_ptrs_.ForAllPtrs(
+        [categories, this](TraceController* controller) {
+          auto binding = new mojo::Binding<TraceDataCollector>(this);
+          TraceDataCollectorPtr ptr;
+          binding->Bind(&ptr);
+          collector_bindings_.push_back(binding);
+          controller->StartTracing(categories, ptr.Pass());
+        });
   }
   void StopAndFlush() override {
-    collector_bindings_.ForAllBindings(
+    controller_ptrs_.ForAllPtrs(
         [](TraceController* controller) { controller->StopTracing(); });
 
     // TODO: We really should keep track of how many connections we have here

[jamesr, 2014/12/19 02:00:59]

what i really want do to is join all controller message pipes up to some timeout

     // and flush + reset the sink after we receive a EndTracing or a detect a
     // pipe closure on all pipes.
     base::MessageLoop::current()->PostDelayedTask(
         FROM_HERE,
-        base::Bind(&TraceDataSink::Flush, base::Unretained(sink_.get())),
+        base::Bind(&TracingApp::AllDataCollected, base::Unretained(this)),
         base::TimeDelta::FromSeconds(1));
   }
 
+  void AllDataCollected() {
+    for (auto p : collector_bindings_)
+      delete p;
+    collector_bindings_.clear();
+    sink_->Flush();
+  }
+
   // tracing::TraceDataCollector implementation.
   void DataCollected(const mojo::String& json) override {
     if (sink_)
       sink_->AddChunk(json.To<std::string>());
   }
-  // tracing::TraceDataCollector implementation.
-  void EndTracing() override {}
 
   scoped_ptr<TraceDataSink> sink_;
-  mojo::WeakBindingSet<TraceDataCollector> collector_bindings_;
+  std::vector<mojo::Binding<TraceDataCollector>*> collector_bindings_;
+  mojo::WeakInterfacePtrSet<TraceController> controller_ptrs_;
   mojo::WeakBindingSet<TraceCoordinator> coordinator_bindings_;
 
   DISALLOW_COPY_AND_ASSIGN(TracingApp);
 };
 
 }  // namespace tracing
 
 MojoResult MojoMain(MojoHandle shell_handle) {
   mojo::ApplicationRunnerChromium runner(new tracing::TracingApp);
   return runner.Run(shell_handle);
 }