Make Chrome Trace work with Android ATrace.

base/debug/trace_event.h

 // 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.
 
 // This header is designed to give you trace_event macros without specifying
 // how the events actually get collected and stored. If you need to expose trace
 // event to some other universe, you can copy-and-paste this file,
 // implement the TRACE_EVENT_API macros, and do any other necessary fixup for
 // the target platform. The end result is that multiple libraries can funnel
 // events through to a shared trace event collector.
@@ skipping 579 matching lines @@
 //                    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)
 #define TRACE_EVENT_API_ADD_TRACE_EVENT \
     base::debug::TraceLog::GetInstance()->AddTraceEvent
 
+// Checks if Android ATrace is enabled.
+#if defined(OS_ANDROID)
+#define TRACE_EVENT_API_IS_ATRACE_ENABLED() \
+    base::debug::TraceLog::IsATraceEnabled()
+#else
+#define TRACE_EVENT_API_IS_ATRACE_ENABLED() false
+#endif
+
 ////////////////////////////////////////////////////////////////////////////////
 
 // Implementation detail: trace event macros create temporary variables
 // to keep instrumentation overhead low. These macros give each temporary
 // variable a unique name based on the line number to prevent name collissions.
 #define INTERNAL_TRACE_EVENT_UID3(a,b) \
     trace_event_unique_##a##b
 #define INTERNAL_TRACE_EVENT_UID2(a,b) \
     INTERNAL_TRACE_EVENT_UID3(a,b)
 #define INTERNAL_TRACE_EVENT_UID(name_prefix) \
     INTERNAL_TRACE_EVENT_UID2(name_prefix, __LINE__)
 
 // Implementation detail: internal macro to create static category.
 // No barriers are needed, because this code is designed to operate safely
 // even when the unsigned char* points to garbage data (which may be the case
 // on processors without cache coherency).
 #define INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category) \
     static base::subtle::AtomicWord INTERNAL_TRACE_EVENT_UID(atomic) = 0; \
     const uint8* INTERNAL_TRACE_EVENT_UID(catstatic) = \
         reinterpret_cast<const uint8*>( \
             base::subtle::NoBarrier_Load(&INTERNAL_TRACE_EVENT_UID(atomic))); \
     if (!INTERNAL_TRACE_EVENT_UID(catstatic)) { \
       INTERNAL_TRACE_EVENT_UID(catstatic) = \
           TRACE_EVENT_API_GET_CATEGORY_ENABLED(category); \
       base::subtle::NoBarrier_Store(&INTERNAL_TRACE_EVENT_UID(atomic), \
           reinterpret_cast<base::subtle::AtomicWord>( \
               INTERNAL_TRACE_EVENT_UID(catstatic))); \
     }
 
+// Implementation detail: internal macro to check if Android ATrace or the
+// current category (using the current static category variable) is enabled.
+#define INTERNAL_TRACE_EVENT_IS_ATRACE_OR_CATEGORY_ENABLED() \
+    TRACE_EVENT_API_IS_ATRACE_ENABLED() || *INTERNAL_TRACE_EVENT_UID(catstatic)
+
 // Implementation detail: internal macro to create static category and add
 // event if the category is enabled.
 #define INTERNAL_TRACE_EVENT_ADD(phase, category, name, flags, ...) \
     do { \
       INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category); \
-      if (*INTERNAL_TRACE_EVENT_UID(catstatic)) { \
+      if (INTERNAL_TRACE_EVENT_IS_ATRACE_OR_CATEGORY_ENABLED()) { \
         trace_event_internal::AddTraceEvent( \
             phase, INTERNAL_TRACE_EVENT_UID(catstatic), name, \
             trace_event_internal::kNoEventId, flags, ##__VA_ARGS__); \
       } \
     } while (0)
 
 // Implementation detail: internal macro to create static category and add begin
 // event if the category is enabled. Also adds the end event when the scope
 // ends.
 #define INTERNAL_TRACE_EVENT_ADD_SCOPED(category, name, ...) \
     INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category); \
     trace_event_internal::TraceEndOnScopeClose \
         INTERNAL_TRACE_EVENT_UID(profileScope); \
-    if (*INTERNAL_TRACE_EVENT_UID(catstatic)) { \
+    if (INTERNAL_TRACE_EVENT_IS_ATRACE_OR_CATEGORY_ENABLED()) { \
       trace_event_internal::AddTraceEvent( \
           TRACE_EVENT_PHASE_BEGIN, \
           INTERNAL_TRACE_EVENT_UID(catstatic), \
           name, trace_event_internal::kNoEventId, \
           TRACE_EVENT_FLAG_NONE, ##__VA_ARGS__); \
       INTERNAL_TRACE_EVENT_UID(profileScope).Initialize( \
           INTERNAL_TRACE_EVENT_UID(catstatic), name); \
     }
 
 // Implementation detail: internal macro to create static category and add begin
 // event if the category is enabled. Also adds the end event when the scope
 // ends. If the elapsed time is < threshold time, the begin/end pair is erased.
 #define INTERNAL_TRACE_EVENT_ADD_SCOPED_IF_LONGER_THAN(threshold, \
         category, name, ...) \
     INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category); \
     trace_event_internal::TraceEndOnScopeCloseThreshold \
         INTERNAL_TRACE_EVENT_UID(profileScope); \
-    if (*INTERNAL_TRACE_EVENT_UID(catstatic)) { \
+    if (INTERNAL_TRACE_EVENT_IS_ATRACE_OR_CATEGORY_ENABLED()) { \
       int INTERNAL_TRACE_EVENT_UID(begin_event_id) = \
         trace_event_internal::AddTraceEvent( \
             TRACE_EVENT_PHASE_BEGIN, \
             INTERNAL_TRACE_EVENT_UID(catstatic), \
             name, trace_event_internal::kNoEventId, \
             TRACE_EVENT_FLAG_NONE, ##__VA_ARGS__); \
       INTERNAL_TRACE_EVENT_UID(profileScope).Initialize( \
           INTERNAL_TRACE_EVENT_UID(catstatic), name, \
           INTERNAL_TRACE_EVENT_UID(begin_event_id), threshold); \
     }
 
 // Implementation detail: internal macro to create static category and add
 // event if the category is enabled.
 #define INTERNAL_TRACE_EVENT_ADD_WITH_ID(phase, category, name, id, flags, \
                                          ...) \
     do { \
       INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category); \
-      if (*INTERNAL_TRACE_EVENT_UID(catstatic)) { \
+      if (INTERNAL_TRACE_EVENT_IS_ATRACE_OR_CATEGORY_ENABLED()) { \
         unsigned char trace_event_flags = flags | TRACE_EVENT_FLAG_HAS_ID; \
         trace_event_internal::TraceID trace_event_trace_id( \
             id, &trace_event_flags); \
         trace_event_internal::AddTraceEvent( \
             phase, INTERNAL_TRACE_EVENT_UID(catstatic), \
             name, trace_event_trace_id.data(), trace_event_flags, \
             ##__VA_ARGS__); \
       } \
     } while (0)
 
@@ skipping 297 matching lines @@
     const char* name;
     int threshold_begin_id;
   };
   Data* p_data_;
   Data data_;
 };
 
 }  // namespace trace_event_internal
 
 #endif  // BASE_DEBUG_TRACE_EVENT_H_