Add Gpu Tracing to Ganesh

src/gpu/GrTracing.h

+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrTracing_DEFINED
+#define GrTracing_DEFINED
+
+#include "GrDrawTarget.h"
+#include "GrTraceMarker.h"
+#include "SkTraceEvent.h"
+
+/**
+ * Marker generation class used for adding and removing markers around code blocks
+ */
+class GrGpuTraceMarkerGenerator : public ::SkNoncopyable {
+public:
+    GrGpuTraceMarkerGenerator() : p_data_(NULL) {}
+
+    ~GrGpuTraceMarkerGenerator() {
+        if (p_data_) {
+            data_.fTarget->removeGpuTraceMarker(&(data_.fTraceMarker));
+        }
+    }
+
+    void Initialize(const char* marker_str, int* marker_counter, GrDrawTarget* target) {
+        data_.fTarget = target;
+        data_.fTraceMarker.fMarker = marker_str;
+        data_.fTraceMarker.fID = *marker_counter;
+        p_data_ = &data_;
+        data_.fTarget->addGpuTraceMarker(&(data_.fTraceMarker));
+    }
+
+private:
+    /**
+     * This Data struct workaround is to avoid initializing all the members
+     * in Data during construction of this object, since this object is always
+     * constructed, even when tracing is disabled. If the members of Data were
+     * members of this class instead, compiler warnings occur about potential
+     * uninitialized accesses.
+     */
+    struct Data {

[bsalomon, 2014/03/24 14:34:38]

Check out SkTLazy.

+        GrDrawTarget* fTarget;
+        GrGpuTraceMarker fTraceMarker;
+    };
+    Data* p_data_;
+    Data data_;
+};
+
+/**
+ * GR_CREATE_TRACE_MARKER will place begin and end trace markers for both
+ * cpu and gpu (if gpu tracing enabled) for the current scope.
+ * marker is of type const char* and target is of type GrDrawTarget*
+ */
+#define GR_CREATE_TRACE_MARKER(name, target)                              \
+    static const char* SK_MACRO_APPEND_LINE(static_name) = name;          \
+    static int SK_MACRO_APPEND_LINE(name_counter) = 0;                    \
+    INTERNAL_GR_CREATE_TRACE_MARKER(SK_MACRO_APPEND_LINE(static_name),    \
+                                    SK_MACRO_APPEND_LINE(name_counter),   \
+                                    target)                               \
+
+#define INTERNAL_GR_CREATE_TRACE_MARKER(name, name_counter, target)       \
+    GR_CREATE_GPU_TRACE_MARKER(name, name_counter, target)                \
+    TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("skia.gpu"),name,              \
+                 "id", name_counter)                                      \
+    sk_atomic_inc(&name_counter);                                         \
+
+#define GR_CREATE_GPU_TRACE_MARKER(name, name_counter, target)            \
+    GrGpuTraceMarkerGenerator SK_MACRO_APPEND_LINE(TMG);                  \
+    if (target->isGpuTracingEnabled()) {                                  \
+        SK_MACRO_APPEND_LINE(TMG).Initialize(name, &name_counter, target);\
+    }                                                                     \
+
+
+#endif
+