// 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 "content/browser/browser_main_loop.h"

#include "base/bind.h"
#include "base/command_line.h"
#include "base/debug/trace_event.h"
#include "base/logging.h"
#include "base/message_loop.h"
#include "base/metrics/field_trial.h"
#include "base/metrics/histogram.h"
#include "base/threading/thread_restrictions.h"
#include "content/browser/browser_thread_impl.h"
#include "content/browser/download/download_file_manager.h"
#include "content/browser/download/save_file_manager.h"
#include "content/browser/in_process_webkit/webkit_thread.h"
#include "content/browser/plugin_service_impl.h"
#include "content/browser/renderer_host/resource_dispatcher_host.h"
#include "content/browser/trace_controller.h"
#include "content/common/hi_res_timer_manager.h"
#include "content/common/sandbox_policy.h"
#include "content/public/browser/browser_main_parts.h"
#include "content/public/browser/browser_shutdown.h"
#include "content/public/browser/content_browser_client.h"
#include "content/public/common/content_switches.h"
#include "content/public/common/main_function_params.h"
#include "content/public/common/result_codes.h"
#include "crypto/nss_util.h"
#include "net/base/network_change_notifier.h"
#include "net/base/ssl_config_service.h"
#include "net/socket/client_socket_factory.h"
#include "net/socket/tcp_client_socket.h"

#if defined(OS_WIN)
#include <windows.h>
#include <commctrl.h>
#include <ole2.h>
#include <shellapi.h>

#include "content/browser/system_message_window_win.h"
#include "ui/base/l10n/l10n_util_win.h"
#include "net/base/winsock_init.h"
#endif

#if defined(OS_LINUX) || defined(OS_OPENBSD)
#include <glib-object.h>
#endif

#if defined(OS_CHROMEOS)
#include <dbus/dbus-glib.h>
#endif

#if defined(TOOLKIT_USES_GTK)
#include "ui/gfx/gtk_util.h"
#endif

#if defined(OS_POSIX) && !defined(OS_MACOSX)
#include <sys/stat.h>
#include "content/browser/renderer_host/render_sandbox_host_linux.h"
#include "content/browser/zygote_host_linux.h"
#endif

#if defined(USE_X11)
#include <X11/Xlib.h>
#endif

namespace {

#if defined(OS_POSIX) && !defined(OS_MACOSX)
void SetupSandbox(const CommandLine& parsed_command_line) {
  // TODO(evanm): move this into SandboxWrapper; I'm just trying to move this
  // code en masse out of chrome_main for now.
  const char* sandbox_binary = NULL;
  struct stat st;

  // In Chromium branded builds, developers can set an environment variable to
  // use the development sandbox. See
  // http://code.google.com/p/chromium/wiki/LinuxSUIDSandboxDevelopment
  if (stat("/proc/self/exe", &st) == 0 && st.st_uid == getuid())
    sandbox_binary = getenv("CHROME_DEVEL_SANDBOX");

#if defined(LINUX_SANDBOX_PATH)
  if (!sandbox_binary)
    sandbox_binary = LINUX_SANDBOX_PATH;
#endif

  std::string sandbox_cmd;
  if (sandbox_binary && !parsed_command_line.HasSwitch(switches::kNoSandbox))
    sandbox_cmd = sandbox_binary;

  // Tickle the sandbox host and zygote host so they fork now.
  RenderSandboxHostLinux* shost = RenderSandboxHostLinux::GetInstance();
  shost->Init(sandbox_cmd);
  ZygoteHost* zhost = ZygoteHost::GetInstance();
  zhost->Init(sandbox_cmd);
}
#endif

#if defined(OS_LINUX) || defined(OS_OPENBSD)
static void GLibLogHandler(const gchar* log_domain,
                           GLogLevelFlags log_level,
                           const gchar* message,
                           gpointer userdata) {
  if (!log_domain)
    log_domain = "<unknown>";
  if (!message)
    message = "<no message>";

  if (strstr(message, "Loading IM context type") ||
      strstr(message, "wrong ELF class: ELFCLASS64")) {
    // http://crbug.com/9643
    // Until we have a real 64-bit build or all of these 32-bit package issues
    // are sorted out, don't fatal on ELF 32/64-bit mismatch warnings and don't
    // spam the user with more than one of them.
    static bool alerted = false;
    if (!alerted) {
      LOG(ERROR) << "Bug 9643: " << log_domain << ": " << message;
      alerted = true;
    }
  } else if (strstr(message, "Unable to retrieve the file info for")) {
    LOG(ERROR) << "GTK File code error: " << message;
  } else if (strstr(message, "Theme file for default has no") ||
             strstr(message, "Theme directory") ||
             strstr(message, "theme pixmap") ||
             strstr(message, "locate theme engine")) {
    LOG(ERROR) << "GTK theme error: " << message;
  } else if (strstr(message, "gtk_drag_dest_leave: assertion")) {
    LOG(ERROR) << "Drag destination deleted: http://crbug.com/18557";
  } else if (strstr(message, "Out of memory") &&
             strstr(log_domain, "<unknown>")) {
    LOG(ERROR) << "DBus call timeout or out of memory: "
               << "http://crosbug.com/15496";
  } else if (strstr(message, "XDG_RUNTIME_DIR variable not set")) {
    LOG(ERROR) << message << " (http://bugs.chromium.org/97293)";
  } else {
    LOG(DFATAL) << log_domain << ": " << message;
  }
}

static void SetUpGLibLogHandler() {
  // Register GLib-handled assertions to go through our logging system.
  const char* kLogDomains[] = { NULL, "Gtk", "Gdk", "GLib", "GLib-GObject" };
  for (size_t i = 0; i < arraysize(kLogDomains); i++) {
    g_log_set_handler(kLogDomains[i],
                      static_cast<GLogLevelFlags>(G_LOG_FLAG_RECURSION |
                                                  G_LOG_FLAG_FATAL |
                                                  G_LOG_LEVEL_ERROR |
                                                  G_LOG_LEVEL_CRITICAL |
                                                  G_LOG_LEVEL_WARNING),
                      GLibLogHandler,
                      NULL);
  }
}
#endif

}  // namespace

namespace content {

// The currently-running BrowserMainLoop.  There can be one or zero.
// This is stored to enable immediate shutdown when needed.
BrowserMainLoop* current_browser_main_loop = NULL;

// This is just to be able to keep ShutdownThreadsAndCleanUp out of
// the public interface of BrowserMainLoop.
class BrowserShutdownImpl {
 public:
  static void ImmediateShutdownAndExitProcess() {
    DCHECK(current_browser_main_loop);
    current_browser_main_loop->ShutdownThreadsAndCleanUp();

#if defined(OS_WIN)
    // At this point the message loop is still running yet we've shut everything
    // down. If any messages are processed we'll likely crash. Exit now.
    ExitProcess(content::RESULT_CODE_NORMAL_EXIT);
#elif defined(OS_POSIX) && !defined(OS_MACOSX)
    _exit(content::RESULT_CODE_NORMAL_EXIT);
#else
    NOTIMPLEMENTED();
#endif
  }
};

void ImmediateShutdownAndExitProcess() {
  BrowserShutdownImpl::ImmediateShutdownAndExitProcess();
}

// BrowserMainLoop construction / destructione =============================

BrowserMainLoop::BrowserMainLoop(const content::MainFunctionParams& parameters)
    : parameters_(parameters),
      parsed_command_line_(parameters.command_line),
      result_code_(content::RESULT_CODE_NORMAL_EXIT) {
  DCHECK(!current_browser_main_loop);
  current_browser_main_loop = this;
#if defined(OS_WIN)
  OleInitialize(NULL);
#endif
}

BrowserMainLoop::~BrowserMainLoop() {
  DCHECK_EQ(this, current_browser_main_loop);
  current_browser_main_loop = NULL;
#if defined(OS_WIN)
  OleUninitialize();
#endif
}

void BrowserMainLoop::Init() {
  parts_.reset(
      GetContentClient()->browser()->CreateBrowserMainParts(parameters_));
}

// BrowserMainLoop stages ==================================================

void BrowserMainLoop::EarlyInitialization() {
#if defined(USE_X11)
  if (parsed_command_line_.HasSwitch(switches::kSingleProcess) ||
      parsed_command_line_.HasSwitch(switches::kInProcessGPU)) {
    if (!XInitThreads()) {
      LOG(ERROR) << "Failed to put Xlib into threaded mode.";
    }
  }
#endif

  if (parts_.get())
    parts_->PreEarlyInitialization();

#if defined(OS_WIN)
  net::EnsureWinsockInit();
#endif

#if !defined(USE_OPENSSL)
  // Use NSS for SSL by default.
  // The default client socket factory uses NSS for SSL by default on
  // Windows and Mac.
  bool init_nspr = false;
#if defined(OS_WIN) || defined(OS_MACOSX)
  if (parsed_command_line_.HasSwitch(switches::kUseSystemSSL)) {
    net::ClientSocketFactory::UseSystemSSL();
  } else {
    init_nspr = true;
  }
#elif defined(USE_NSS)
  init_nspr = true;
#endif
  if (init_nspr) {
    // We want to be sure to init NSPR on the main thread.
    crypto::EnsureNSPRInit();
  }
#endif  // !defined(USE_OPENSSL)

#if defined(OS_POSIX) && !defined(OS_MACOSX)
  SetupSandbox(parsed_command_line_);
#endif

  if (parsed_command_line_.HasSwitch(switches::kDisableSSLFalseStart))
    net::SSLConfigService::DisableFalseStart();
  if (parsed_command_line_.HasSwitch(switches::kEnableSSLCachedInfo))
    net::SSLConfigService::EnableCachedInfo();
  if (parsed_command_line_.HasSwitch(
          switches::kEnableDNSCertProvenanceChecking)) {
    net::SSLConfigService::EnableDNSCertProvenanceChecking();
  }

  // TODO(abarth): Should this move to InitializeNetworkOptions?  This doesn't
  // seem dependent on SSL initialization().
  if (parsed_command_line_.HasSwitch(switches::kEnableTcpFastOpen))
    net::set_tcp_fastopen_enabled(true);

  if (parts_.get())
    parts_->PostEarlyInitialization();
}

void BrowserMainLoop::MainMessageLoopStart() {
  if (parts_.get())
    parts_->PreMainMessageLoopStart();

#if defined(OS_WIN)
  // If we're running tests (ui_task is non-null), then the ResourceBundle
  // has already been initialized.
  if (!parameters_.ui_task) {
    // Override the configured locale with the user's preferred UI language.
    l10n_util::OverrideLocaleWithUILanguageList();
  }
#endif

  // Must first NULL pointer or we hit a DCHECK that the newly constructed
  // message loop is the current one.
  main_message_loop_.reset();
  main_message_loop_.reset(new MessageLoop(MessageLoop::TYPE_UI));

  InitializeMainThread();

  // Start tracing to a file if needed.
  if (base::debug::TraceLog::GetInstance()->IsEnabled())
    TraceController::GetInstance()->InitStartupTracing(parsed_command_line_);

  system_monitor_.reset(new base::SystemMonitor);
  hi_res_timer_manager_.reset(new HighResolutionTimerManager);

  network_change_notifier_.reset(net::NetworkChangeNotifier::Create());

#if defined(OS_WIN)
  system_message_window_.reset(new SystemMessageWindowWin);
#endif

  // Prior to any processing happening on the io thread, we create the
  // plugin service as it is predominantly used from the io thread,
  // but must be created on the main thread. The service ctor is
  // inexpensive and does not invoke the io_thread() accessor.
  PluginService::GetInstance()->Init();

  if (parts_.get())
    parts_->PostMainMessageLoopStart();
}

void BrowserMainLoop::RunMainMessageLoopParts(
    bool* completed_main_message_loop) {
  if (parts_.get())
    parts_->PreCreateThreads();

  base::Thread::Options default_options;
  base::Thread::Options io_message_loop_options;
  io_message_loop_options.message_loop_type = MessageLoop::TYPE_IO;
  base::Thread::Options ui_message_loop_options;
  ui_message_loop_options.message_loop_type = MessageLoop::TYPE_UI;

  // Start threads in the order they occur in the BrowserThread::ID
  // enumeration, except for BrowserThread::UI which is the main
  // thread.
  //
  // Must be size_t so we can increment it.
  for (size_t thread_id = BrowserThread::UI + 1;
       thread_id < BrowserThread::ID_COUNT;
       ++thread_id) {
    scoped_ptr<BrowserProcessSubThread>* thread_to_start = NULL;
    base::Thread::Options* options = &default_options;

    switch (thread_id) {
      case BrowserThread::DB:
        thread_to_start = &db_thread_;
        break;
      case BrowserThread::WEBKIT_DEPRECATED:
        // Special case as WebKitThread is a separate
        // type.  |thread_to_start| is not used in this case.
        break;
      case BrowserThread::FILE_USER_BLOCKING:
        thread_to_start = &file_user_blocking_thread_;
        break;
      case BrowserThread::FILE:
        thread_to_start = &file_thread_;
#if defined(OS_WIN)
        // On Windows, the FILE thread needs to be have a UI message loop
        // which pumps messages in such a way that Google Update can
        // communicate back to us.
        options = &ui_message_loop_options;
#else
        options = &io_message_loop_options;
#endif
        break;
      case BrowserThread::PROCESS_LAUNCHER:
        thread_to_start = &process_launcher_thread_;
        break;
      case BrowserThread::CACHE:
        thread_to_start = &cache_thread_;
        options = &io_message_loop_options;
        break;
      case BrowserThread::IO:
        thread_to_start = &io_thread_;
        options = &io_message_loop_options;
        break;
      case BrowserThread::UI:
      case BrowserThread::ID_COUNT:
      default:
        NOTREACHED();
        break;
    }

    BrowserThread::ID id = static_cast<BrowserThread::ID>(thread_id);

    if (thread_id == BrowserThread::WEBKIT_DEPRECATED) {
      webkit_thread_.reset(new WebKitThread);
      webkit_thread_->Initialize();
    } else if (thread_to_start) {
      (*thread_to_start).reset(new BrowserProcessSubThread(id));
      (*thread_to_start)->StartWithOptions(*options);
    } else {
      NOTREACHED();
    }
  }

  BrowserThreadsStarted();

  if (parts_.get())
    parts_->PreMainMessageLoopRun();

  TRACE_EVENT_BEGIN_ETW("BrowserMain:MESSAGE_LOOP", 0, "");
  // If the UI thread blocks, the whole UI is unresponsive.
  // Do not allow disk IO from the UI thread.
  base::ThreadRestrictions::SetIOAllowed(false);

  bool ran_main_loop = false;
  if (parts_.get())
    ran_main_loop = parts_->MainMessageLoopRun(&result_code_);

  if (!ran_main_loop)
    MainMessageLoopRun();

  TRACE_EVENT_END_ETW("BrowserMain:MESSAGE_LOOP", 0, "");

  if (completed_main_message_loop)
    *completed_main_message_loop = true;

  ShutdownThreadsAndCleanUp();
}

void BrowserMainLoop::ShutdownThreadsAndCleanUp() {
  // Teardown may start in PostMainMessageLoopRun, and during teardown we
  // need to be able to perform IO.
  base::ThreadRestrictions::SetIOAllowed(true);
  BrowserThread::PostTask(
      BrowserThread::IO, FROM_HERE,
      base::Bind(base::IgnoreResult(&base::ThreadRestrictions::SetIOAllowed),
                 true));

  if (parts_.get())
    parts_->PostMainMessageLoopRun();

  // Cancel pending requests and prevent new requests.
  if (resource_dispatcher_host_.get())
    resource_dispatcher_host_.get()->Shutdown();

  // Must be size_t so we can subtract from it.
  for (size_t thread_id = BrowserThread::ID_COUNT - 1;
       thread_id >= (BrowserThread::UI + 1);
       --thread_id) {
    // Find the thread object we want to stop. Looping over all valid
    // BrowserThread IDs and DCHECKing on a missing case in the switch
    // statement helps avoid a mismatch between this code and the
    // BrowserThread::ID enumeration.
    //
    // The destruction order is the reverse order of occurrence in the
    // BrowserThread::ID list. The rationale for the order is as
    // follows (need to be filled in a bit):
    //
    //
    // - The IO thread is the only user of the CACHE thread.
    //
    // - The PROCESS_LAUNCHER thread must be stopped after IO in case
    //   the IO thread posted a task to terminate a process on the
    //   process launcher thread.
    //
    // - (Not sure why FILE needs to stop before WEBKIT.)
    //
    // - The WEBKIT thread (which currently is the responsibility of
    //   the embedder to stop, by destroying ResourceDispatcherHost
    //   before the DB thread is stopped)
    //
    // - (Not sure why DB stops last.)
    scoped_ptr<BrowserProcessSubThread>* thread_to_stop = NULL;
    switch (thread_id) {
      case BrowserThread::DB:
        thread_to_stop = &db_thread_;
        break;
      case BrowserThread::WEBKIT_DEPRECATED:
        // Special case as WebKitThread is a separate
        // type.  |thread_to_stop| is not used in this case.

        // Need to destroy ResourceDispatcherHost before PluginService
        // and since it caches a pointer to it.
        resource_dispatcher_host_.reset();
        break;
      case BrowserThread::FILE_USER_BLOCKING:
        thread_to_stop = &file_user_blocking_thread_;
        break;
      case BrowserThread::FILE:
        thread_to_stop = &file_thread_;

        // Clean up state that lives on or uses the file_thread_ before
        // it goes away.
        if (resource_dispatcher_host_.get()) {
          resource_dispatcher_host_.get()->download_file_manager()->Shutdown();
          resource_dispatcher_host_.get()->save_file_manager()->Shutdown();
        }
        break;
      case BrowserThread::PROCESS_LAUNCHER:
        thread_to_stop = &process_launcher_thread_;
        break;
      case BrowserThread::CACHE:
        thread_to_stop = &cache_thread_;
        break;
      case BrowserThread::IO:
        thread_to_stop = &io_thread_;
        break;
      case BrowserThread::UI:
      case BrowserThread::ID_COUNT:
      default:
        NOTREACHED();
        break;
    }

    BrowserThread::ID id = static_cast<BrowserThread::ID>(thread_id);

    if (id == BrowserThread::WEBKIT_DEPRECATED) {
      webkit_thread_.reset();
    } else if (thread_to_stop) {
      thread_to_stop->reset();
    } else {
      NOTREACHED();
    }
  }

  // Close the blocking I/O pool after the other threads. Other threads such
  // as the I/O thread may need to schedule work like closing files or flushing
  // data during shutdown, so the blocking pool needs to be available. There
  // may also be slow operations pending that will blcok shutdown, so closing
  // it here (which will block until required operations are complete) gives
  // more head start for those operations to finish.
  BrowserThreadImpl::ShutdownThreadPool();

  if (parts_.get())
    parts_->PostDestroyThreads();
}

void BrowserMainLoop::InitializeMainThread() {
  const char* kThreadName = "CrBrowserMain";
  base::PlatformThread::SetName(kThreadName);
  main_message_loop_->set_thread_name(kThreadName);

  // Register the main thread by instantiating it, but don't call any methods.
  main_thread_.reset(new BrowserThreadImpl(BrowserThread::UI,
                                           MessageLoop::current()));
}


void BrowserMainLoop::BrowserThreadsStarted() {
  // RDH needs the IO thread to be created.
  resource_dispatcher_host_.reset(new ResourceDispatcherHost());
}

void BrowserMainLoop::InitializeToolkit() {
  // TODO(evan): this function is rather subtle, due to the variety
  // of intersecting ifdefs we have.  To keep it easy to follow, there
  // are no #else branches on any #ifs.
  // TODO(stevenjb): Move platform specific code into platform specific Parts
  // (Need to add InitializeToolkit stage to BrowserParts).
#if defined(OS_LINUX) || defined(OS_OPENBSD)
  // Glib type system initialization. Needed at least for gconf,
  // used in net/proxy/proxy_config_service_linux.cc. Most likely
  // this is superfluous as gtk_init() ought to do this. It's
  // definitely harmless, so retained as a reminder of this
  // requirement for gconf.
  g_type_init();

#if defined(USE_AURA)
  setlocale(LC_ALL, "");
#endif

#if !defined(USE_AURA)
  gfx::GtkInitFromCommandLine(parsed_command_line_);
#endif

  SetUpGLibLogHandler();
#endif

#if defined(TOOLKIT_GTK)
  // It is important for this to happen before the first run dialog, as it
  // styles the dialog as well.
  gfx::InitRCStyles();
#endif

#if defined(OS_WIN)
  // Init common control sex.
  INITCOMMONCONTROLSEX config;
  config.dwSize = sizeof(config);
  config.dwICC = ICC_WIN95_CLASSES;
  if (!InitCommonControlsEx(&config))
    LOG_GETLASTERROR(FATAL);
#endif

  if (parts_.get())
    parts_->ToolkitInitialized();
}

void BrowserMainLoop::MainMessageLoopRun() {
  if (parameters_.ui_task)
    MessageLoopForUI::current()->PostTask(FROM_HERE, *parameters_.ui_task);

#if defined(OS_MACOSX)
  MessageLoopForUI::current()->Run();
#else
  MessageLoopForUI::current()->RunWithDispatcher(NULL);
#endif
}

}  // namespace content