Make Chrome Trace work with Android ATrace.

base/debug/trace_event_impl.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 "base/debug/trace_event_impl.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/debug/leak_annotations.h"
 #include "base/debug/trace_event.h"
-#include "base/file_util.h"
 #include "base/format_macros.h"
 #include "base/lazy_instance.h"
 #include "base/memory/singleton.h"
 #include "base/process_util.h"
 #include "base/stl_util.h"
 #include "base/stringprintf.h"
 #include "base/string_tokenizer.h"
 #include "base/string_util.h"
 #include "base/sys_info.h"
 #include "base/third_party/dynamic_annotations/dynamic_annotations.h"
@@ skipping 40 matching lines @@
 unsigned char g_category_enabled[TRACE_EVENT_MAX_CATEGORIES] = { 0 };
 const int g_category_already_shutdown = 0;
 const int g_category_categories_exhausted = 1;
 const int g_category_metadata = 2;
 int g_category_index = 3; // skip initial 3 categories
 
 // The most-recently captured name of the current thread
 LazyInstance<ThreadLocalPointer<const char> >::Leaky
     g_current_thread_name = LAZY_INSTANCE_INITIALIZER;
 
-void AppendValueAsJSON(unsigned char type,
-                       TraceEvent::TraceValue value,
-                       std::string* out) {
-  std::string::size_type start_pos;
-  switch (type) {
-    case TRACE_VALUE_TYPE_BOOL:
-      *out += value.as_bool ? "true" : "false";
-      break;
-    case TRACE_VALUE_TYPE_UINT:
-      StringAppendF(out, "%" PRIu64, static_cast<uint64>(value.as_uint));
-      break;
-    case TRACE_VALUE_TYPE_INT:
-      StringAppendF(out, "%" PRId64, static_cast<int64>(value.as_int));
-      break;
-    case TRACE_VALUE_TYPE_DOUBLE:
-      StringAppendF(out, "%f", value.as_double);
-      break;
-    case TRACE_VALUE_TYPE_POINTER:
-      // JSON only supports double and int numbers.
-      // So as not to lose bits from a 64-bit pointer, output as a hex string.
-      StringAppendF(out, "\"%" PRIx64 "\"", static_cast<uint64>(
-                                     reinterpret_cast<intptr_t>(
-                                     value.as_pointer)));
-      break;
-    case TRACE_VALUE_TYPE_STRING:
-    case TRACE_VALUE_TYPE_COPY_STRING:
-      *out += "\"";
-      start_pos = out->size();
-      *out += value.as_string ? value.as_string : "NULL";
-      // insert backslash before special characters for proper json format.
-      while ((start_pos = out->find_first_of("\\\"", start_pos)) !=
-             std::string::npos) {
-        out->insert(start_pos, 1, '\\');
-        // skip inserted escape character and following character.
-        start_pos += 2;
-      }
-      *out += "\"";
-      break;
-    default:
-      NOTREACHED() << "Don't know how to print this value";
-      break;
-  }
-}
-
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 //
 // TraceEvent
 //
 ////////////////////////////////////////////////////////////////////////////////
 
 namespace {
 
@@ skipping 91 matching lines @@
       if (arg_is_copy[i])
         CopyTraceEventParameter(&ptr, &arg_values_[i].as_string, end);
     }
     DCHECK_EQ(end, ptr) << "Overrun by " << ptr - end;
   }
 }
 
 TraceEvent::~TraceEvent() {
 }
 
+// static
+void TraceEvent::AppendValueAsJSON(unsigned char type,
+                                   TraceEvent::TraceValue value,
+                                   std::string* out) {
+  std::string::size_type start_pos;
+  switch (type) {
+    case TRACE_VALUE_TYPE_BOOL:
+      *out += value.as_bool ? "true" : "false";
+      break;
+    case TRACE_VALUE_TYPE_UINT:
+      StringAppendF(out, "%" PRIu64, static_cast<uint64>(value.as_uint));
+      break;
+    case TRACE_VALUE_TYPE_INT:
+      StringAppendF(out, "%" PRId64, static_cast<int64>(value.as_int));
+      break;
+    case TRACE_VALUE_TYPE_DOUBLE:
+      StringAppendF(out, "%f", value.as_double);
+      break;
+    case TRACE_VALUE_TYPE_POINTER:
+      // JSON only supports double and int numbers.
+      // So as not to lose bits from a 64-bit pointer, output as a hex string.
+      StringAppendF(out, "\"%" PRIx64 "\"", static_cast<uint64>(
+                                     reinterpret_cast<intptr_t>(
+                                     value.as_pointer)));
+      break;
+    case TRACE_VALUE_TYPE_STRING:
+    case TRACE_VALUE_TYPE_COPY_STRING:
+      *out += "\"";
+      start_pos = out->size();
+      *out += value.as_string ? value.as_string : "NULL";
+      // insert backslash before special characters for proper json format.
+      while ((start_pos = out->find_first_of("\\\"", start_pos)) !=
+             std::string::npos) {
+        out->insert(start_pos, 1, '\\');
+        // skip inserted escape character and following character.
+        start_pos += 2;
+      }
+      *out += "\"";
+      break;
+    default:
+      NOTREACHED() << "Don't know how to print this value";
+      break;
+  }
+}
+
 void TraceEvent::AppendEventsAsJSON(const std::vector<TraceEvent>& events,
                                     size_t start,
                                     size_t count,
                                     std::string* out) {
   for (size_t i = 0; i < count && start + i < events.size(); ++i) {
     if (i > 0)
       *out += ",";
     events[i + start].AppendAsJSON(out);
   }
 }
@@ skipping 298 matching lines @@
   dispatching_to_observer_list_ = false;
 
   enabled_ = false;
   included_categories_.clear();
   excluded_categories_.clear();
   watch_category_ = NULL;
   watch_event_name_ = "";
   for (int i = 0; i < g_category_index; i++)
     g_category_enabled[i] = 0;
   AddThreadNameMetadataEvents();
+#if defined(OS_ANDROID)
   AddClockSyncMetadataEvents();
+#endif
 }
 
 void TraceLog::SetEnabled(bool enabled) {
   if (enabled)
     SetEnabled(std::vector<std::string>(), std::vector<std::string>());
   else
     SetDisabled();
 }
 
 void TraceLog::AddEnabledStateObserver(EnabledStateChangedObserver* listener) {
@@ skipping 40 matching lines @@
                             const char* name,
                             unsigned long long id,
                             int num_args,
                             const char** arg_names,
                             const unsigned char* arg_types,
                             const unsigned long long* arg_values,
                             int threshold_begin_id,
                             long long threshold,
                             unsigned char flags) {
   DCHECK(name);
+
+#if defined(OS_ANDROID)
+  if (IsATraceEnabled()) {

[jbates, 2012/10/30 20:22:14]

This if looks redundant

[Xianzhu, 2012/10/30 21:45:01]

Done.

+    SendToATrace(phase, GetCategoryName(category_enabled), name,
+                 num_args, arg_names, arg_types, arg_values);
+  }
+#endif
+
   TimeTicks now = TimeTicks::NowFromSystemTraceTime();
   NotificationHelper notifier(this);
   int ret_begin_id = -1;
   {
     AutoLock lock(lock_);
     if (!*category_enabled)
       return -1;
     if (logged_events_.size() >= kTraceEventBufferSize)
       return -1;
 
@@ skipping 117 matching lines @@
     notifier.SendNotificationIfAny();
   }
 }
 
 void TraceLog::CancelWatchEvent() {
   AutoLock lock(lock_);
   watch_category_ = NULL;
   watch_event_name_ = "";
 }
 
-void TraceLog::AddClockSyncMetadataEvents() {
-#if defined(OS_ANDROID)
-  // Since Android does not support sched_setaffinity, we cannot establish clock
-  // sync unless the scheduler clock is set to global. If the trace_clock file
-  // can't be read, we will assume the kernel doesn't support tracing and do
-  // nothing.
-  std::string clock_mode;
-  if (!file_util::ReadFileToString(
-          FilePath("/sys/kernel/debug/tracing/trace_clock"),
-          &clock_mode))
-    return;
-
-  if (clock_mode != "local [global]\n") {
-    DLOG(WARNING) <<
-        "The kernel's tracing clock must be set to global in order for " <<
-        "trace_event to be synchronized with . Do this by\n" <<
-        "  echo global > /sys/kerel/debug/tracing/trace_clock";
-    return;
-  }
-
-  // Android's kernel trace system has a trace_marker feature: this is a file on
-  // debugfs that takes the written data and pushes it onto the trace
-  // buffer. So, to establish clock sync, we write our monotonic clock into that
-  // trace buffer.
-  TimeTicks now = TimeTicks::NowFromSystemTraceTime();
-
-  double now_in_seconds = now.ToInternalValue() / 1000000.0;
-  std::string marker =
-      StringPrintf("trace_event_clock_sync: parent_ts=%f\n",
-                   now_in_seconds);
-  if (file_util::WriteFile(
-          FilePath("/sys/kernel/debug/tracing/trace_marker"),
-          marker.c_str(), marker.size()) == -1) {
-    DLOG(WARNING) << "Couldn't write to /sys/kernel/debug/tracing/trace_marker";
-    return;
-  }
-#endif
-}
-
 void TraceLog::AddThreadNameMetadataEvents() {
   lock_.AssertAcquired();
   for(base::hash_map<int, std::string>::iterator it = thread_names_.begin();
       it != thread_names_.end();
       it++) {
     if (!it->second.empty()) {
       int num_args = 1;
       const char* arg_name = "name";
       unsigned char arg_type;
       unsigned long long arg_value;
@@ skipping 22 matching lines @@
   // Create a FNV hash from the process ID for XORing.
   // See http://isthe.com/chongo/tech/comp/fnv/ for algorithm details.
   unsigned long long offset_basis = 14695981039346656037ull;
   unsigned long long fnv_prime = 1099511628211ull;
   unsigned long long pid = static_cast<unsigned long long>(process_id_);
   process_id_hash_ = (offset_basis ^ pid) * fnv_prime;
 }
 
 }  // namespace debug
 }  // namespace base