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 "SkTraceEvent.h"
+
+class GrGpuTraceMarker {
+public:
+    GrGpuTraceMarker(const char* marker, int idCounter) : fMarker(marker), fID(idCounter) {}
+
+    bool operator<(const GrGpuTraceMarker& rhs) const {
+        return this->fMarker < rhs.fMarker || (this->fMarker == rhs.fMarker && this->fID < rhs.fID);
+    }
+
+    bool operator==(const GrGpuTraceMarker& rhs) const {
+        return (this->fID == rhs.fID && this->fMarker == rhs.fMarker);
+    }
+
+    const char* fMarker;
+    int fID;
+};
+
+template<typename T>
+class SkTDArray;
+
+class GrTraceMarkerSet {
+public:
+    GrTraceMarkerSet() {}
+
+    GrTraceMarkerSet(const GrTraceMarkerSet& other);
+
+    // Adds marker to the set.
+    void add(const GrGpuTraceMarker& marker); 
+    // Adds all markers from one set into this set.
+    void addSet(const GrTraceMarkerSet& markerSet);
+
+    void remove(const GrGpuTraceMarker& marker);
+
+    int count() const;
+
+    // First sorts fMarkerArray and returns a string of the format
+    // MarkerName1(#,#,...)%MarkerName2(#,#,...):... where MarkerName is the
+    // marker string used in the TraceMarker and the (#,#,..) is a list of instance
+    // id's for the the given marker string
+    SkString toString() const; 
+
+    class Iter;
+
+    Iter begin() const;
+
+    Iter end() const;
+
+private:
+    mutable SkTDArray<GrGpuTraceMarker> fMarkerArray;
+};
+
+class GrDrawTarget;
+
+/**
+ * Marker generation class used for adding and removing markers around code blocks
+ */
+class GrGpuTraceMarkerGenerator : public ::SkNoncopyable {
+public:
+    GrGpuTraceMarkerGenerator(const char* marker_str, int* marker_counter, GrDrawTarget* target);

[bsalomon, 2014/03/20 16:32:53]

I think these should be inlinable. Otherwise we add a pair of function calls for
every marker whether tracing is enabled or not.

+    ~GrGpuTraceMarkerGenerator();
+
+private:
+    GrDrawTarget* fTarget;
+    GrGpuTraceMarker fTraceMarker;
+};
+
+////////// macros to place around the internal draw calls //////////////////

[bsalomon, 2014/03/20 16:32:53]

Can we use the /** style comments?
                *
                */

+// 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(marker_str, target)                        \

[bsalomon, 2014/03/20 16:32:53]

If we want to do tracing in SkGpuDevice.cpp we'll need a version of this that
operates on GrContext. But it seems OK to keep it at GrContext and below for
now.

+    static const char* static_str = marker_str;                           \
+    static int marker_counter = 0;                                        \

[bsalomon, 2014/03/20 16:32:53]

I think these statics need some mangling to make sure they're unique if two are
inserted in the same scope.

+    GR_CREATE_GPU_TRACE_MARKER(static_str, target, marker_counter)        \
+    TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("skia.gpu"), static_str,       \
+                 "id", marker_counter)                                    \
+    sk_atomic_inc(&marker_counter);                                       \
+
+#define GR_CREATE_GPU_TRACE_MARKER(marker_str, target, marker_counter)    \
+    GrGpuTraceMarkerGenerator SK_MACRO_APPEND_LINE(TMG)(static_str,       \
+                                                   &marker_counter,       \
+                                                   target);               \
+
+////////////////////////////////////////////////////////////////////////////
+
+
+#endif
+