Output a Trace Event metadata event identifying each named thread

Move the generic dummy implementation of
TraceEvent::emitOneRecording() to a source file of its own. (That is
the one which is used in test and tool executables.)

Signed-off-by: Tor Lillqvist <tml@collabora.com>
Change-Id: I81cab07e5a6852b42d278a5446c13c3825cf546e

3 files changed, 33 insertions, 4 deletions

diff --git a/common/DummyTraceEventEmitter.cpp b/common/DummyTraceEventEmitter.cpp
new file mode 100644
index 0000000000..cb1d0dc2fb
--- /dev/null
+++ b/common/DummyTraceEventEmitter.cpp
@@ -0,0 +1,18 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+// Compile and link this into test and utility executables that need it to link
+
+#include <common/TraceEvent.hpp>
+
+void TraceEvent::emitOneRecording(const std::string &recording)
+{
+    // Dummy.
+    (void) recording;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/common/TraceEvent.hpp b/common/TraceEvent.hpp
index 7e2fc3ac49..8780bb24e7 100644
--- a/common/TraceEvent.hpp
+++ b/common/TraceEvent.hpp
@@ -102,10 +102,6 @@ protected:
         }
     }
 
-    // This method needs to be implemented separately in the WSD and Kit processes. (WSD writes the
-    // actual Trace Event log file, Kit just forwards the Trace Events to WSD for output.)
-    static void emitOneRecording(const std::string &recording);
-
 public:
     static void startRecording();
     static void stopRecording();
@@ -120,6 +116,10 @@ public:
         emitInstantEvent(name, createArgsString(args));
     }
 
+    // This method needs to be implemented separately in the WSD and Kit processes. (WSD writes the
+    // actual Trace Event log file, Kit just forwards the Trace Events to WSD for output.)
+    static void emitOneRecording(const std::string &recording);
+
     TraceEvent(const TraceEvent&) = delete;
     void operator=(const TraceEvent&) = delete;
 };
diff --git a/common/Util.cpp b/common/Util.cpp
index 5af9d6b4e2..15875e16db 100644
--- a/common/Util.cpp
+++ b/common/Util.cpp
@@ -62,6 +62,7 @@
 #include "Common.hpp"
 #include "Log.hpp"
 #include "Protocol.hpp"
+#include "TraceEvent.hpp"
 
 namespace Util
 {
@@ -573,6 +574,16 @@ namespace Util
         [[NSThread currentThread] setName:[NSString stringWithUTF8String:ThreadName]];
         LOG_INF("Thread " << getThreadId() << ") is now called [" << s << ']');
 #endif
+
+        // Emit a metadata Trace Event identifying this thread. This will invoke a different function
+        // depending on which executable this is in.
+        TraceEvent::emitOneRecording("{\"name\":\"thread_name\",\"ph\":\"M\",\"args\":{\"name\":\""
+                                     + s
+                                     + "\"},\"pid\":"
+                                     + std::to_string(getpid())
+                                     + ",\"tid\":"
+                                     + std::to_string(Util::getThreadId())
+                                     + "},");
     }
 
     const char *getThreadName()