Clearing the old systrace plumbing to make way for improved one (#149)

Author: mganandraj

ReactCommon/CMakeLists.txt

@@ -43,7 +43,6 @@ endif(WIN32)
 
 if(ANDROID)
 	set(SOURCES ${SOURCES}
-		cxxreact/fbsystrace.cpp
 		cxxreact/JSBigString.cpp
 		)
 endif(ANDROID)

ReactCommon/cxxreact/Android.mk

@@ -11,7 +11,6 @@ LOCAL_MODULE := reactnative
 
 LOCAL_SRC_FILES := \
   CxxNativeModule.cpp \
-  fbsystrace.cpp \
   Instance.cpp \
   JSBigString.cpp \
   JSBundleType.cpp \

ReactCommon/cxxreact/SystraceSection.h

@@ -9,71 +9,40 @@
 #include <fbsystrace.h>
 #endif
 
-#include <string>
-#include <chrono>
-
 namespace facebook {
 namespace react {
 
-void SystraceBeginSection(const char* name, const char* args) noexcept;
-void SystraceEndSection(const char* name, const char* args, std::chrono::nanoseconds duration) noexcept;
-
 /**
  * This is a convenience class to avoid lots of verbose profiling
  * #ifdefs.  If WITH_FBSYSTRACE is not defined, the optimizer will
  * remove this completely.  If it is defined, it will behave as
- * FbSystraceSection, with the right tag provided.
+ * FbSystraceSection, with the right tag provided. Use two separate classes to
+ * to ensure that the ODR rule isn't violated, that is, if WITH_FBSYSTRACE has
+ * different values in different files, there is no inconsistency in the sizes
+ * of defined symbols.
  */
-struct SystraceSection {
-public:
-  template<typename... ConvertsToStringPiece>
-  explicit SystraceSection(const char* name, ConvertsToStringPiece&&... args)
 #ifdef WITH_FBSYSTRACE
-    : m_section(TRACE_TAG_REACT_CXX_BRIDGE, name, std::forward<ConvertsToStringPiece>(args)...)
-#elif defined(WITH_OFFICE_TRACING)
-    : m_start(std::chrono::steady_clock::now())
-    , m_name{name}
-    , m_args{concatArgs(std::forward<ConvertsToStringPiece>(args)...)}
-  {
-    SystraceBeginSection(m_name.c_str(), m_args.c_str());
-  }
-
-  ~SystraceSection()
-  {
-    SystraceEndSection(m_name.c_str(), m_args.c_str(), std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::steady_clock::now()-m_start));
-  }
-
-private:
-  std::string concatArgs() noexcept
-  {
-    return "";
-  }
-
+struct ConcreteSystraceSection {
+public:
   template<typename... ConvertsToStringPiece>
-  std::string concatArgs(const char* name, const std::string& value, ConvertsToStringPiece&&... rest) noexcept
-  {
-    return std::string(name) + "=" + value + "|" + concatArgs(std::forward<ConvertsToStringPiece>(rest)...);
-  }
-#else
+  explicit
+  ConcreteSystraceSection(__unused const char* name, __unused ConvertsToStringPiece&&... args)
+    : m_section(TRACE_TAG_REACT_CXX_BRIDGE, name, args...)
   {}
-#endif
 
-#ifdef WITH_FBSYSTRACE
+private:
   fbsystrace::FbSystraceSection m_section;
-#elif defined(WITH_OFFICE_TRACING)
-  std::string m_name;
-  std::string m_args;
-  std::chrono::time_point<std::chrono::steady_clock> m_start;
-#endif
 };
-
-// Some placeholder definitions to satisfy linker.. as we are enabling some unintented code paths when enabling these macros.
-#if defined(WITH_OFFICE_TRACING)
-#define TRACE_TAG_REACT_CXX_BRIDGE 0
-struct FbSystraceAsyncFlow{
-    static void begin(uint64_t /*tag*/, const char* /*name*/, int /*cookie*/) {}
-    static void end(uint64_t /*tag*/, const char* /*name*/, int /*cookie*/) {}
+using SystraceSection = ConcreteSystraceSection;
+#else
+struct DummySystraceSection {
+public:
+  template<typename... ConvertsToStringPiece>
+  explicit
+  DummySystraceSection(__unused const char* name, __unused ConvertsToStringPiece&&... args)
+    {}
 };
+using SystraceSection = DummySystraceSection;
 #endif
 
 }}