mojo_runner: Get --trace-start working with generic mojo_runner.

Android didn't like our magic to automatically include a connection to mojo:tracing in ApplicationImpl. This does things the explicit way: including a mojo:TracingImpl in each and every mojo application package.

BUG=534895

Review URL: https://codereview.chromium.org/1459453003

Cr-Commit-Position: refs/heads/master@{#360434}

6 files changed, 47 insertions, 0 deletions

diff --git a/mojo/runner/desktop/launcher_process.cc b/mojo/runner/desktop/launcher_process.cc
index 4fa6956..b55953c 100644
--- a/mojo/runner/desktop/launcher_process.cc
+++ b/mojo/runner/desktop/launcher_process.cc
@@ -15,6 +15,7 @@
 #include "base/message_loop/message_loop.h"
 #include "base/path_service.h"
 #include "base/synchronization/waitable_event.h"
+#include "base/threading/platform_thread.h"
 #include "mojo/runner/context.h"
 #include "mojo/runner/switches.h"
 #include "mojo/shell/switches.h"
@@ -31,6 +32,8 @@ int LauncherProcessMain(const GURL& mojo_url, const base::Closure& callback) {
   // http://crbug.com/546644
   command_line->AppendSwitch(switches::kMojoNoSandbox);
 
+  base::PlatformThread::SetName("mojo_runner");
+
   // We want the shell::Context to outlive the MessageLoop so that pipes are
   // all gracefully closed / error-out before we try to shut the Context down.
   Context shell_context;
diff --git a/mojo/services/network/BUILD.gn b/mojo/services/network/BUILD.gn
index 6b20a9b..76d6bdc 100644
--- a/mojo/services/network/BUILD.gn
+++ b/mojo/services/network/BUILD.gn
@@ -100,6 +100,7 @@ source_set("lib") {
     "//mojo/public/cpp/system:system",
     "//mojo/services/network/public/cpp",
     "//mojo/services/network/public/interfaces",
+    "//mojo/services/tracing/public/cpp",
     "//net",
     "//net:extras",
     "//net:http_server",
diff --git a/mojo/services/network/network_service_delegate.cc b/mojo/services/network/network_service_delegate.cc
index 14e642b..0a43964 100644
--- a/mojo/services/network/network_service_delegate.cc
+++ b/mojo/services/network/network_service_delegate.cc
@@ -129,6 +129,7 @@ void NetworkServiceDelegate::Initialize(ApplicationImpl* app) {
   worker_thread = io_worker_thread_->task_runner();
 #endif
   context_.reset(new NetworkContext(base_path, worker_thread, this));
+  tracing_.Initialize(app);
 }
 
 bool NetworkServiceDelegate::ConfigureIncomingConnection(
diff --git a/mojo/services/network/network_service_delegate.h b/mojo/services/network/network_service_delegate.h
index 216f961..16b2f96 100644
--- a/mojo/services/network/network_service_delegate.h
+++ b/mojo/services/network/network_service_delegate.h
@@ -16,6 +16,7 @@
 #include "mojo/services/network/public/interfaces/network_service.mojom.h"
 #include "mojo/services/network/public/interfaces/url_loader_factory.mojom.h"
 #include "mojo/services/network/public/interfaces/web_socket_factory.mojom.h"
+#include "mojo/services/tracing/public/cpp/tracing_impl.h"
 
 namespace sql {
 class ScopedMojoFilesystemVFS;
@@ -69,6 +70,7 @@ class NetworkServiceDelegate : public ApplicationDelegate,
 
  private:
   ApplicationImpl* app_;
+  mojo::TracingImpl tracing_;
 
   // Observers that want notifications that our worker thread is going away.
   base::ObserverList<NetworkServiceDelegateObserver> observers_;
diff --git a/mojo/services/tracing/public/cpp/tracing_impl.cc b/mojo/services/tracing/public/cpp/tracing_impl.cc
index 788cd31..1cffe03 100644
--- a/mojo/services/tracing/public/cpp/tracing_impl.cc
+++ b/mojo/services/tracing/public/cpp/tracing_impl.cc
@@ -4,6 +4,9 @@
 
 #include "mojo/services/tracing/public/cpp/tracing_impl.h"
 
+#include "base/lazy_instance.h"
+#include "base/synchronization/lock.h"
+#include "base/threading/platform_thread.h"
 #include "base/trace_event/trace_event_impl.h"
 #include "mojo/application/public/cpp/application_impl.h"
 
@@ -13,6 +16,22 @@
 #endif
 
 namespace mojo {
+namespace {
+
+// Controls access to |g_tracing_singleton_created|, which can be accessed from
+// different threads.
+base::LazyInstance<base::Lock>::Leaky g_singleton_lock =
+    LAZY_INSTANCE_INITIALIZER;
+
+// Whether we are the first TracingImpl to be created in this mojo
+// application. The first TracingImpl in a physical mojo application connects
+// to the mojo:tracing service.
+//
+// If this is a ContentHandler, it will outlive all its served Applications. If
+// this is a raw mojo application, it is the only Application served.
+bool g_tracing_singleton_created = false;
+
+}
 
 TracingImpl::TracingImpl() {
 }
@@ -21,6 +40,17 @@ TracingImpl::~TracingImpl() {
 }
 
 void TracingImpl::Initialize(ApplicationImpl* app) {
+  {
+    base::AutoLock lock(g_singleton_lock.Get());
+    if (g_tracing_singleton_created)
+      return;
+    g_tracing_singleton_created = true;
+  }
+
+  // This will only set the name for the first app in a loaded mojo file. It's
+  // up to something like CoreServices to name its own child threads.
+  base::PlatformThread::SetName(app->url());
+
   mojo::URLRequestPtr request(mojo::URLRequest::New());
   request->url = mojo::String::From("mojo:tracing");
   connection_ = app->ConnectToApplication(request.Pass());
diff --git a/mojo/services/tracing/public/cpp/tracing_impl.h b/mojo/services/tracing/public/cpp/tracing_impl.h
index 648023f..b832ef49 100644
--- a/mojo/services/tracing/public/cpp/tracing_impl.h
+++ b/mojo/services/tracing/public/cpp/tracing_impl.h
@@ -15,6 +15,16 @@ namespace mojo {
 class ApplicationConnection;
 class ApplicationImpl;
 
+// Connects to mojo:tracing during your Application's Initialize() call once
+// per process.
+//
+// We need to deal with multiple ways of packaging mojo applications
+// together. We'll need to deal with packages that use the mojo.ContentHandler
+// interface to bundle several Applciations into a single physical on disk
+// mojo binary, and with those same services each in their own mojo binary.
+//
+// Have your bundle ContentHandler own a TracingImpl, and each Application own
+// a TracingImpl. In bundles, the second TracingImpl will be a no-op.
 class TracingImpl : public InterfaceFactory<tracing::TraceProvider> {
  public:
   TracingImpl();