src/chrome/common/profiling.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 "chrome/common/profiling.h"
   6
   7 #include "base/at_exit.h"
   8 #include "base/bind.h"
   9 #include "base/command_line.h"
  10 #include "base/debug/profiler.h"
  11 #include "base/lazy_instance.h"
  12 #include "base/message_loop/message_loop.h"
  13 #include "base/strings/string_util.h"
  14 #include "base/threading/thread.h"
  15 #include "chrome/common/chrome_switches.h"
  16 #include "v8/include/v8.h"
  17
  18 namespace {
  19
  20 base::debug::AddDynamicSymbol add_dynamic_symbol_func = NULL;
  21 base::debug::MoveDynamicSymbol move_dynamic_symbol_func = NULL;
  22
  23 void JitCodeEventHandler(const v8::JitCodeEvent* event) {
  24   DCHECK_NE(static_cast<base::debug::AddDynamicSymbol>(NULL),
  25             add_dynamic_symbol_func);
  26   DCHECK_NE(static_cast<base::debug::MoveDynamicSymbol>(NULL),
  27             move_dynamic_symbol_func);
  28
  29   switch (event->type) {
  30     case v8::JitCodeEvent::CODE_ADDED:
  31       add_dynamic_symbol_func(event->code_start, event->code_len,
  32                               event->name.str, event->name.len);
  33       break;
  34
  35     case v8::JitCodeEvent::CODE_MOVED:
  36       move_dynamic_symbol_func(event->code_start, event->new_code_start);
  37       break;
  38
  39     default:
  40       break;
  41   }
  42 }
  43
  44 std::string GetProfileName() {
  45   static const char kDefaultProfileName[] = "chrome-profile-{type}-{pid}";
  46   CR_DEFINE_STATIC_LOCAL(std::string, profile_name, ());
  47
  48   if (profile_name.empty()) {
  49     const CommandLine& command_line = *CommandLine::ForCurrentProcess();
  50     if (command_line.HasSwitch(switches::kProfilingFile))
  51       profile_name = command_line.GetSwitchValueASCII(switches::kProfilingFile);
  52     else
  53       profile_name = std::string(kDefaultProfileName);
  54     std::string process_type =
  55         command_line.GetSwitchValueASCII(switches::kProcessType);
  56     std::string type = process_type.empty() ?
  57         std::string("browser") : std::string(process_type);
  58     ReplaceSubstringsAfterOffset(&profile_name, 0, "{type}", type.c_str());
  59   }
  60   return profile_name;
  61 }
  62
  63 void FlushProfilingData(base::Thread* thread) {
  64   static const int kProfilingFlushSeconds = 10;
  65
  66   if (!Profiling::BeingProfiled())
  67     return;
  68
  69   base::debug::FlushProfiling();
  70   static int flush_seconds;
  71   if (!flush_seconds) {
  72     const CommandLine& command_line = *CommandLine::ForCurrentProcess();
  73     std::string profiling_flush =
  74         command_line.GetSwitchValueASCII(switches::kProfilingFlush);
  75     if (!profiling_flush.empty()) {
  76       flush_seconds = atoi(profiling_flush.c_str());
  77       DCHECK(flush_seconds > 0);
  78     } else {
  79       flush_seconds = kProfilingFlushSeconds;
  80     }
  81   }
  82   thread->message_loop()->PostDelayedTask(
  83       FROM_HERE,
  84       base::Bind(&FlushProfilingData, thread),
  85       base::TimeDelta::FromSeconds(flush_seconds));
  86 }
  87
  88 class ProfilingThreadControl {
  89  public:
  90   ProfilingThreadControl() : thread_(NULL) {}
  91
  92   void Start() {
  93     base::AutoLock locked(lock_);
  94
  95     if (thread_ && thread_->IsRunning())
  96       return;
  97     thread_ = new base::Thread("Profiling_Flush");
  98     thread_->Start();
  99     thread_->message_loop()->PostTask(
 100         FROM_HERE, base::Bind(&FlushProfilingData, thread_));
 101   }
 102
 103   void Stop() {
 104     base::AutoLock locked(lock_);
 105
 106     if (!thread_ || !thread_->IsRunning())
 107       return;
 108     thread_->Stop();
 109     delete thread_;
 110     thread_ = NULL;
 111   }
 112
 113  private:
 114   base::Thread* thread_;
 115   base::Lock lock_;
 116
 117   DISALLOW_COPY_AND_ASSIGN(ProfilingThreadControl);
 118 };
 119
 120 base::LazyInstance<ProfilingThreadControl>::Leaky
 121     g_flush_thread_control = LAZY_INSTANCE_INITIALIZER;
 122
 123 } // namespace
 124
 125 // static
 126 void Profiling::ProcessStarted() {
 127   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
 128   std::string process_type =
 129       command_line.GetSwitchValueASCII(switches::kProcessType);
 130
 131   // Establish the V8 profiling hooks if we're an instrumented binary.
 132   if (base::debug::IsBinaryInstrumented()) {
 133     base::debug::ReturnAddressLocationResolver resolve_func =
 134         base::debug::GetProfilerReturnAddrResolutionFunc();
 135
 136     if (resolve_func != NULL) {
 137       v8::V8::SetReturnAddressLocationResolver(resolve_func);
 138     }
 139
 140     // Set up the JIT code entry handler and the symbol callbacks if the
 141     // profiler supplies them.
 142     // TODO(siggi): Maybe add a switch or an environment variable to turn off
 143     //     V8 profiling?
 144     base::debug::DynamicFunctionEntryHook entry_hook_func =
 145         base::debug::GetProfilerDynamicFunctionEntryHookFunc();
 146     add_dynamic_symbol_func = base::debug::GetProfilerAddDynamicSymbolFunc();
 147     move_dynamic_symbol_func = base::debug::GetProfilerMoveDynamicSymbolFunc();
 148
 149     v8::Isolate* isolate = v8::Isolate::GetCurrent();
 150     if (isolate != NULL &&
 151         entry_hook_func != NULL &&
 152         add_dynamic_symbol_func != NULL &&
 153         move_dynamic_symbol_func != NULL) {
 154       v8::V8::SetFunctionEntryHook(isolate, entry_hook_func);
 155       v8::V8::SetJitCodeEventHandler(v8::kJitCodeEventDefault,
 156                                      &JitCodeEventHandler);
 157     }
 158   }
 159
 160   if (command_line.HasSwitch(switches::kProfilingAtStart)) {
 161     std::string process_type_to_start =
 162         command_line.GetSwitchValueASCII(switches::kProfilingAtStart);
 163     if (process_type == process_type_to_start)
 164       Start();
 165   }
 166 }
 167
 168 // static
 169 void Profiling::Start() {
 170   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
 171   bool flush = command_line.HasSwitch(switches::kProfilingFlush);
 172   base::debug::StartProfiling(GetProfileName());
 173
 174   // Schedule profile data flushing for single process because it doesn't
 175   // get written out correctly on exit.
 176   if (flush)
 177     g_flush_thread_control.Get().Start();
 178 }
 179
 180 // static
 181 void Profiling::Stop() {
 182   g_flush_thread_control.Get().Stop();
 183   base::debug::StopProfiling();
 184 }
 185
 186 // static
 187 bool Profiling::BeingProfiled() {
 188   return base::debug::BeingProfiled();
 189 }
 190
 191 // static
 192 void Profiling::Toggle() {
 193   if (BeingProfiled())
 194     Stop();
 195   else
 196     Start();
 197 }