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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/child/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/lazy_instance.h"
12 #include "base/message_loop/message_loop.h"
13 #include "base/metrics/statistics_recorder.h"
14 #include "base/process/process_handle.h"
15 #include "base/strings/string_number_conversions.h"
16 #include "base/strings/utf_string_conversions.h"
17 #include "base/threading/thread.h"
18 #include "base/threading/thread_local.h"
19 #include "content/child/child_thread.h"
20 
21 #if defined(OS_ANDROID)
22 #include "base/debug/debugger.h"
23 #endif
24 
25 #if defined(OS_POSIX) && !defined(OS_ANDROID)
SigUSR1Handler(int signal)26 static void SigUSR1Handler(int signal) { }
27 #endif
28 
29 namespace content {
30 
31 namespace {
32 
33 base::LazyInstance<base::ThreadLocalPointer<ChildProcess> > g_lazy_tls =
34     LAZY_INSTANCE_INITIALIZER;
35 }
36 
ChildProcess()37 ChildProcess::ChildProcess()
38     : ref_count_(0),
39       shutdown_event_(true, false),
40       io_thread_("Chrome_ChildIOThread") {
41   DCHECK(!g_lazy_tls.Pointer()->Get());
42   g_lazy_tls.Pointer()->Set(this);
43 
44   base::StatisticsRecorder::Initialize();
45 
46   // We can't recover from failing to start the IO thread.
47   CHECK(io_thread_.StartWithOptions(
48       base::Thread::Options(base::MessageLoop::TYPE_IO, 0)));
49 
50 #if defined(OS_ANDROID)
51   io_thread_.SetPriority(base::kThreadPriority_Display);
52 #endif
53 }
54 
~ChildProcess()55 ChildProcess::~ChildProcess() {
56   DCHECK(g_lazy_tls.Pointer()->Get() == this);
57 
58   // Signal this event before destroying the child process.  That way all
59   // background threads can cleanup.
60   // For example, in the renderer the RenderThread instances will be able to
61   // notice shutdown before the render process begins waiting for them to exit.
62   shutdown_event_.Signal();
63 
64   // Kill the main thread object before nulling child_process, since
65   // destruction code might depend on it.
66   if (main_thread_) {  // null in unittests.
67     main_thread_->Shutdown();
68     main_thread_.reset();
69   }
70 
71   g_lazy_tls.Pointer()->Set(NULL);
72 }
73 
main_thread()74 ChildThread* ChildProcess::main_thread() {
75   return main_thread_.get();
76 }
77 
set_main_thread(ChildThread * thread)78 void ChildProcess::set_main_thread(ChildThread* thread) {
79   main_thread_.reset(thread);
80 }
81 
AddRefProcess()82 void ChildProcess::AddRefProcess() {
83   DCHECK(!main_thread_.get() ||  // null in unittests.
84          base::MessageLoop::current() == main_thread_->message_loop());
85   ref_count_++;
86 }
87 
ReleaseProcess()88 void ChildProcess::ReleaseProcess() {
89   DCHECK(!main_thread_.get() ||  // null in unittests.
90          base::MessageLoop::current() == main_thread_->message_loop());
91   DCHECK(ref_count_);
92   if (--ref_count_)
93     return;
94 
95   if (main_thread_)  // null in unittests.
96     main_thread_->OnProcessFinalRelease();
97 }
98 
current()99 ChildProcess* ChildProcess::current() {
100   return g_lazy_tls.Pointer()->Get();
101 }
102 
GetShutDownEvent()103 base::WaitableEvent* ChildProcess::GetShutDownEvent() {
104   return &shutdown_event_;
105 }
106 
WaitForDebugger(const std::string & label)107 void ChildProcess::WaitForDebugger(const std::string& label) {
108 #if defined(OS_WIN)
109 #if defined(GOOGLE_CHROME_BUILD)
110   std::string title = "Google Chrome";
111 #else  // CHROMIUM_BUILD
112   std::string title = "Chromium";
113 #endif  // CHROMIUM_BUILD
114   title += " ";
115   title += label;  // makes attaching to process easier
116   std::string message = label;
117   message += " starting with pid: ";
118   message += base::IntToString(base::GetCurrentProcId());
119   ::MessageBox(NULL, UTF8ToWide(message).c_str(), UTF8ToWide(title).c_str(),
120                MB_OK | MB_SETFOREGROUND);
121 #elif defined(OS_POSIX)
122 #if defined(OS_ANDROID)
123   LOG(ERROR) << label << " waiting for GDB.";
124   // Wait 24 hours for a debugger to be attached to the current process.
125   base::debug::WaitForDebugger(24 * 60 * 60, false);
126 #else
127   // TODO(playmobil): In the long term, overriding this flag doesn't seem
128   // right, either use our own flag or open a dialog we can use.
129   // This is just to ease debugging in the interim.
130   LOG(ERROR) << label
131              << " ("
132              << getpid()
133              << ") paused waiting for debugger to attach. "
134              << "Send SIGUSR1 to unpause.";
135   // Install a signal handler so that pause can be woken.
136   struct sigaction sa;
137   memset(&sa, 0, sizeof(sa));
138   sa.sa_handler = SigUSR1Handler;
139   sigaction(SIGUSR1, &sa, NULL);
140 
141   pause();
142 #endif  // defined(OS_ANDROID)
143 #endif  // defined(OS_POSIX)
144 }
145 
146 }  // namespace content
147