content/common/child_process.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/common/child_process.h"
   6
   7 #if defined(OS_POSIX) && !defined(OS_ANDROID)
   8 #include <signal.h>  // For SigUSR1Handler below.
   9 #endif
  10
  11 #include "base/message_loop.h"
  12 #include "base/metrics/statistics_recorder.h"
  13 #include "base/process_util.h"
  14 #include "base/string_number_conversions.h"
  15 #include "base/threading/thread.h"
  16 #include "base/utf_string_conversions.h"
  17 #include "content/common/child_thread.h"
  18
  19 #if defined(OS_ANDROID)
  20 #include "base/debug/debugger.h"
  21 #endif
  22
  23 #if defined(OS_POSIX) && !defined(OS_ANDROID)
  24 static void SigUSR1Handler(int signal) { }
  25 #endif
  26
  27 namespace content {
  28
  29 ChildProcess* ChildProcess::child_process_;
  30
  31 ChildProcess::ChildProcess()
  32     : ref_count_(0),
  33       shutdown_event_(true, false),
  34       io_thread_("Chrome_ChildIOThread") {
  35   DCHECK(!child_process_);
  36   child_process_ = this;
  37
  38   base::StatisticsRecorder::Initialize();
  39
  40   // We can't recover from failing to start the IO thread.
  41   CHECK(io_thread_.StartWithOptions(
  42             base::Thread::Options(MessageLoop::TYPE_IO, 0)));
  43 }
  44
  45 ChildProcess::~ChildProcess() {
  46   DCHECK(child_process_ == this);
  47
  48   // Signal this event before destroying the child process.  That way all
  49   // background threads can cleanup.
  50   // For example, in the renderer the RenderThread instances will be able to
  51   // notice shutdown before the render process begins waiting for them to exit.
  52   shutdown_event_.Signal();
  53
  54   // Kill the main thread object before nulling child_process_, since
  55   // destruction code might depend on it.
  56   main_thread_.reset();
  57
  58   child_process_ = NULL;
  59 }
  60
  61 ChildThread* ChildProcess::main_thread() {
  62   return main_thread_.get();
  63 }
  64
  65 void ChildProcess::set_main_thread(ChildThread* thread) {
  66   main_thread_.reset(thread);
  67 }
  68
  69 void ChildProcess::AddRefProcess() {
  70   DCHECK(!main_thread_.get() ||  // null in unittests.
  71          MessageLoop::current() == main_thread_->message_loop());
  72   ref_count_++;
  73 }
  74
  75 void ChildProcess::ReleaseProcess() {
  76   DCHECK(!main_thread_.get() ||  // null in unittests.
  77          MessageLoop::current() == main_thread_->message_loop());
  78   DCHECK(ref_count_);
  79   DCHECK(child_process_);
  80   if (--ref_count_)
  81     return;
  82
  83   if (main_thread_.get())  // null in unittests.
  84     main_thread_->OnProcessFinalRelease();
  85 }
  86
  87 base::WaitableEvent* ChildProcess::GetShutDownEvent() {
  88   DCHECK(child_process_);
  89   return &child_process_->shutdown_event_;
  90 }
  91
  92 void ChildProcess::WaitForDebugger(const std::string& label) {
  93 #if defined(OS_WIN)
  94 #if defined(GOOGLE_CHROME_BUILD)
  95   std::string title = "Google Chrome";
  96 #else  // CHROMIUM_BUILD
  97   std::string title = "Chromium";
  98 #endif  // CHROMIUM_BUILD
  99   title += " ";
 100   title += label;  // makes attaching to process easier
 101   std::string message = label;
 102   message += " starting with pid: ";
 103   message += base::IntToString(base::GetCurrentProcId());
 104   ::MessageBox(NULL, UTF8ToWide(message).c_str(), UTF8ToWide(title).c_str(),
 105                MB_OK | MB_SETFOREGROUND);
 106 #elif defined(OS_POSIX)
 107 #if defined(OS_ANDROID)
 108   LOG(ERROR) << label << " waiting for GDB.";
 109   // Wait 24 hours for a debugger to be attached to the current process.
 110   base::debug::WaitForDebugger(24 * 60 * 60, false);
 111 #else
 112   // TODO(playmobil): In the long term, overriding this flag doesn't seem
 113   // right, either use our own flag or open a dialog we can use.
 114   // This is just to ease debugging in the interim.
 115   LOG(ERROR) << label
 116              << " ("
 117              << getpid()
 118              << ") paused waiting for debugger to attach @ pid";
 119   // Install a signal handler so that pause can be woken.
 120   struct sigaction sa;
 121   memset(&sa, 0, sizeof(sa));
 122   sa.sa_handler = SigUSR1Handler;
 123   sigaction(SIGUSR1, &sa, NULL);
 124
 125   pause();
 126 #endif  // defined(OS_ANDROID)
 127 #endif  // defined(OS_POSIX)
 128 }
 129
 130 }  // namespace content