Include the thread name in the Trace Events emitted from the C++ code, too

Make sure to avoid most of the code path through createArgsString() if
Trace Event generation is not turned on.

Signed-off-by: Tor Lillqvist <tml@collabora.com>
Change-Id: Id86b2c9b4ded9d402647b7a12b9290d0122ba2aa

2 files changed, 49 insertions, 31 deletions

diff --git a/common/TraceEvent.cpp b/common/TraceEvent.cpp
index cde80aabe7..1aba7720a1 100644
--- a/common/TraceEvent.cpp
+++ b/common/TraceEvent.cpp
@@ -20,27 +20,22 @@ thread_local int TraceEvent::threadLocalNesting = 0; // level of overlapped zone
 
 static std::mutex mutex;
 
-void TraceEvent::emitInstantEvent(const std::string& name, const std::string& args)
+void TraceEvent::emitInstantEvent(const std::string& name, const std::string& argsOrEmpty)
 {
     if (!recordingOn)
         return;
 
-#ifdef TEST_TRACEEVENT_EXE
-    static thread_local int threadId = 0;
-    static int threadCounter = 1;
-
-    if (!threadId)
-        threadId = threadCounter++;
-#else
-    auto threadId = Util::getThreadId();
-#endif
+    std::string args;
+    if (argsOrEmpty.length() == 0)
+        args = createDefaultArgsString();
+    else
+        args = argsOrEmpty;
 
     emitOneRecording("{"
                      "\"name\":\""
                      + name
                      + "\","
                        "\"ph\":\"i\""
-                     + args
                      + ",\"ts\":"
                      + std::to_string(std::chrono::duration_cast<std::chrono::microseconds>(
                               std::chrono::system_clock::now().time_since_epoch())
@@ -50,7 +45,9 @@ void TraceEvent::emitInstantEvent(const std::string& name, const std::string& ar
                      + std::to_string(getpid())
                      + ","
                        "\"tid\":"
-                     + std::to_string(threadId)
+                     + std::to_string(getThreadId())
+                     + ",\"args\":"
+                     + args
                      + "}"
                      // We add a trailing comma and newline, it is up to the code that handles these "recordings"
                      // (outputs them into a JSON array) to remove the final comma before adding the terminating
@@ -70,19 +67,17 @@ void ProfileZone::emitRecording()
 {
     assert(recordingOn);
 
-#ifdef TEST_TRACEEVENT_EXE
-    static thread_local int threadId = 0;
-    static int threadCounter = 1;
-
-    if (!threadId)
-        threadId = threadCounter++;
-#else
-    auto threadId = Util::getThreadId();
-#endif
     auto now = std::chrono::system_clock::now();
 
     // Generate a single "Complete Event" (type X)
     auto duration = now - _createTime;
+
+    std::string args;
+    if (_args.length() == 0)
+        args = createDefaultArgsString();
+    else
+        args = _args;
+
     std::string recordingData(
         "{"
         "\"name\":\""
@@ -101,8 +96,9 @@ void ProfileZone::emitRecording()
         + std::to_string(_pid)
         + ","
           "\"tid\":"
-        + std::to_string(threadId)
-        + _args
+        + std::to_string(getThreadId())
+        + ",\"args\":"
+        + args
         + "}"
         // We emit a trailing comma and newline, it is up to the code that handles these "recordings"
         // (outputs them into a JSON array) to remove the final comma before emiting the terminating
diff --git a/common/TraceEvent.hpp b/common/TraceEvent.hpp
index 6316fbaa41..7e2fc3ac49 100644
--- a/common/TraceEvent.hpp
+++ b/common/TraceEvent.hpp
@@ -40,19 +40,40 @@ protected:
     std::string _args;
     thread_local static int threadLocalNesting; // For use only by the ProfileZone derived class
 
-    // Returns a string that can be inserted into the string representation of a JSON object between
-    // two other properties. The string is either completely empty, or starts with a comma and
-    // contains the property name "args" and as its value an object.
+    static long getThreadId()
+    {
+#ifdef TEST_TRACEEVENT_EXE
+        static thread_local int threadId = 0;
+        static std::atomic<int> threadCounter(1);
+
+        if (!threadId)
+            threadId = threadCounter++;
+        return threadId;
+#else
+    return Util::getThreadId();
+#endif
+    }
+
+    static std::string getThreadName()
+    {
+#ifdef TEST_TRACEEVENT_EXE
+        return "thread-" + std::to_string(getThreadId());
+#else
+        return Util::getThreadName();
+#endif
+    }
+
+    static std::string createDefaultArgsString()
+    {
+        return "{\"thread\":\"" + std::string(getThreadName()) + "\"}";
+    }
 
     static std::string createArgsString(const std::map<std::string, std::string>& args)
     {
         if (!recordingOn)
-            return "";
-
-        if (args.size() == 0)
-            return "";
+            return "0";
 
-        std::string result = ",\"args\":{";
+        std::string result = "{";
         bool first = true;
         for (auto i : args)
         {
@@ -65,6 +86,7 @@ protected:
             result += '"';
             first = false;
         }
+        result += ",\"thread\":\"" + std::string(getThreadName()) + "\"";
         result += '}';
 
         return result;