Reland "Add --serial-id option to host_forwarder."

tools/android/forwarder2/device_forwarder_main.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 <signal.h>
-#include <stdio.h>
 #include <stdlib.h>
 
+#include <iostream>
 #include <string>
 
 #include "base/at_exit.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread.h"
 #include "tools/android/forwarder2/common.h"
 #include "tools/android/forwarder2/daemon.h"
 #include "tools/android/forwarder2/device_controller.h"
 #include "tools/android/forwarder2/pipe_notifier.h"
 
 namespace forwarder2 {
 namespace {
 
 // Leaky global instance, accessed from the signal handler.
 forwarder2::PipeNotifier* g_notifier = NULL;
 
 const int kBufSize = 256;
 
+const char kUnixDomainSocketPath[] = "chrome_device_forwarder";
 const char kDaemonIdentifier[] = "chrome_device_forwarder_daemon";
 
-const char kKillServerCommand[] = "kill-server";
-const char kStartCommand[] = "start";
-
 void KillHandler(int /* unused */) {
   CHECK(g_notifier);
   if (!g_notifier->Notify())
     exit(1);
 }
 
 // Lets the daemon fetch the exit notifier file descriptor.
 int GetExitNotifierFD() {
   DCHECK(g_notifier);
   return g_notifier->receiver_fd();
 }
 
 class ServerDelegate : public Daemon::ServerDelegate {
  public:
+  ServerDelegate() : initialized_(false) {}
+
   // Daemon::ServerDelegate:
   virtual void Init() OVERRIDE {
     DCHECK(!g_notifier);
     g_notifier = new forwarder2::PipeNotifier();
     signal(SIGTERM, KillHandler);
     signal(SIGINT, KillHandler);
     controller_thread_.reset(new base::Thread("controller_thread"));
     controller_thread_->Start();
   }
 
   virtual void OnClientConnected(scoped_ptr<Socket> client_socket) OVERRIDE {
-    char buf[kBufSize];
-    const int bytes_read = client_socket->Read(buf, sizeof(buf));
-    if (bytes_read <= 0) {
-      if (client_socket->DidReceiveEvent())
-        return;
-      PError("Read()");
-      return;
-    }
-    const std::string adb_socket_path(buf, bytes_read);
-    if (adb_socket_path == adb_socket_path_) {
+    if (initialized_) {
       client_socket->WriteString("OK");
       return;
     }
-    if (!adb_socket_path_.empty()) {
-      client_socket->WriteString(
-          base::StringPrintf(
-              "ERROR: Device controller already running (adb_socket_path=%s)",
-              adb_socket_path_.c_str()));
-      return;
-    }
-    adb_socket_path_ = adb_socket_path;
     controller_thread_->message_loop()->PostTask(
         FROM_HERE,
-        base::Bind(&ServerDelegate::StartController, adb_socket_path,
-                   GetExitNotifierFD(), base::Passed(&client_socket)));
+        base::Bind(&ServerDelegate::StartController, GetExitNotifierFD(),
+                   base::Passed(&client_socket)));
+    initialized_ = true;
   }
 
   virtual void OnServerExited() OVERRIDE {}
 
  private:
-  static void StartController(const std::string& adb_socket_path,
-                              int exit_notifier_fd,
+  static void StartController(int exit_notifier_fd,
                               scoped_ptr<Socket> client_socket) {
     forwarder2::DeviceController controller(exit_notifier_fd);
-    if (!controller.Init(adb_socket_path)) {
+    if (!controller.Init(kUnixDomainSocketPath)) {
       client_socket->WriteString(
           base::StringPrintf("ERROR: Could not initialize device controller "
                              "with ADB socket path: %s",
-                             adb_socket_path.c_str()));
+                             kUnixDomainSocketPath));
       return;
     }
     client_socket->WriteString("OK");
     client_socket->Close();
     // Note that the following call is blocking which explains why the device
     // controller has to live on a separate thread (so that the daemon command
     // server is not blocked).
     controller.Start();
   }
 
   base::AtExitManager at_exit_manager_;  // Used by base::Thread.
   scoped_ptr<base::Thread> controller_thread_;
-  std::string adb_socket_path_;
+  bool initialized_;
 };
 
 class ClientDelegate : public Daemon::ClientDelegate {
  public:
-  ClientDelegate(const std::string& adb_socket)
-      : adb_socket_(adb_socket),
-        has_failed_(false) {
-  }
+  ClientDelegate() : has_failed_(false) {}
 
   bool has_failed() const { return has_failed_; }
 
   // Daemon::ClientDelegate:
   virtual void OnDaemonReady(Socket* daemon_socket) OVERRIDE {
-    // Send the adb socket path to the daemon.
-    CHECK(daemon_socket->Write(adb_socket_.c_str(),
-                               adb_socket_.length()));
     char buf[kBufSize];
     const int bytes_read = daemon_socket->Read(
         buf, sizeof(buf) - 1 /* leave space for null terminator */);
     CHECK_GT(bytes_read, 0);
     DCHECK(bytes_read < sizeof(buf));
     buf[bytes_read] = 0;
     base::StringPiece msg(buf, bytes_read);
     if (msg.starts_with("ERROR")) {
       LOG(ERROR) << msg;
       has_failed_ = true;
       return;
     }
   }
 
  private:
-  const std::string adb_socket_;
   bool has_failed_;
 };
 
 int RunDeviceForwarder(int argc, char** argv) {
-  if (argc != 2) {
-    fprintf(stderr,
-            "Usage: %s kill-server|<adb_socket>\n"
-            "  <adb_socket> is the abstract Unix Domain Socket path "
-            "where Adb is configured to forward from.\n", argv[0]);
+  CommandLine::Init(argc, argv);  // Needed by logging.
+  const bool kill_server = CommandLine::ForCurrentProcess()->HasSwitch(
+      "kill-server");
+  if ((kill_server && argc != 2) || (!kill_server && argc != 1)) {
+    std::cerr << "Usage: device_forwarder [--kill-server]" << std::endl;
     return 1;
   }
-  CommandLine::Init(argc, argv);  // Needed by logging.
-  const char* const command =
-      !strcmp(argv[1], kKillServerCommand) ? kKillServerCommand : kStartCommand;
-  ClientDelegate client_delegate(argv[1]);
+  ClientDelegate client_delegate;
   ServerDelegate daemon_delegate;
   const char kLogFilePath[] = "";  // Log to logcat.
   Daemon daemon(kLogFilePath, kDaemonIdentifier, &client_delegate,
                 &daemon_delegate, &GetExitNotifierFD);
 
-  if (command == kKillServerCommand)
+  if (kill_server)
     return !daemon.Kill();
 
-  DCHECK(command == kStartCommand);
   if (!daemon.SpawnIfNeeded())
     return 1;
   return client_delegate.has_failed();
 }
 
 }  // namespace
 }  // namespace forwarder2
 
 int main(int argc, char** argv) {
   return forwarder2::RunDeviceForwarder(argc, argv);
 }