From 6f33547d757fb1394d1e643cdc226ae30b2edbc6 Mon Sep 17 00:00:00 2001
From: Gali Nelle <galinelle.mapbox@gmail.com>
Date: Sun, 9 Feb 2020 17:09:01 +0200
Subject: Add tracing entry points in the rendering pipeline

This also includes a default tracing implementation that does not require
hooking into a platform instrumentation, but simply stores timestamps
into an array that can be dumped into a json file.

Among possible use cases, dumping such metrics to file in CI to detect
regressions of specific stages of the pipeline.
---
 platform/glfw/glfw_renderer_frontend.cpp | 11 ++++++++++-
 platform/glfw/glfw_renderer_frontend.hpp |  2 ++
 platform/glfw/glfw_view.cpp              | 17 +++++++++++++++++
 3 files changed, 29 insertions(+), 1 deletion(-)

(limited to 'platform')

diff --git a/platform/glfw/glfw_renderer_frontend.cpp b/platform/glfw/glfw_renderer_frontend.cpp
index 46f1309901..0c180985b8 100644
--- a/platform/glfw/glfw_renderer_frontend.cpp
+++ b/platform/glfw/glfw_renderer_frontend.cpp
@@ -2,6 +2,7 @@
 
 #include <mbgl/renderer/renderer.hpp>
 #include <mbgl/gfx/backend_scope.hpp>
+#include <mbgl/perf/runtime_metrics.hpp>
 
 GLFWRendererFrontend::GLFWRendererFrontend(std::unique_ptr<mbgl::Renderer> renderer_, GLFWView& glfwView_)
     : glfwView(glfwView_)
@@ -30,7 +31,8 @@ void GLFWRendererFrontend::render() {
     assert(renderer);
     
     if (!updateParameters) return;
-    
+    MBGL_TRACE_RENDERER_BEGINRECORD(update);
+    MBGL_TRACE_RENDERER_BEGIN(attach);
     mbgl::gfx::BackendScope guard { glfwView.getRendererBackend(), mbgl::gfx::BackendScope::ScopeType::Implicit };
 
     // onStyleImageMissing might be called during a render. The user implemented method
@@ -38,10 +40,17 @@ void GLFWRendererFrontend::render() {
     // Copy the shared pointer here so that the parameters aren't destroyed while `render(...)` is
     // still using them.
     auto updateParameters_ = updateParameters;
+    MBGL_TRACE_RENDERER_END(attach);
     renderer->render(updateParameters_);
+    MBGL_TRACE_RENDERER_ENDRECORD(update);
 }
 
 mbgl::Renderer* GLFWRendererFrontend::getRenderer() {
     assert(renderer);
     return renderer.get();
 }
+
+void GLFWRendererFrontend::setRecordFrame(bool enabled)
+{
+    recordFrames = enabled;
+}
diff --git a/platform/glfw/glfw_renderer_frontend.hpp b/platform/glfw/glfw_renderer_frontend.hpp
index c992fe20fe..966f30d69a 100644
--- a/platform/glfw/glfw_renderer_frontend.hpp
+++ b/platform/glfw/glfw_renderer_frontend.hpp
@@ -21,9 +21,11 @@ public:
     void render();
     
     mbgl::Renderer* getRenderer();
+    void setRecordFrame(bool enabled);
 
 private:
     GLFWView& glfwView;
     std::unique_ptr<mbgl::Renderer> renderer;
     std::shared_ptr<mbgl::UpdateParameters> updateParameters;
+    bool recordFrames = false;
 };
diff --git a/platform/glfw/glfw_view.cpp b/platform/glfw/glfw_view.cpp
index 3d10f2c654..1c042983aa 100644
--- a/platform/glfw/glfw_view.cpp
+++ b/platform/glfw/glfw_view.cpp
@@ -23,11 +23,16 @@
 #include <mbgl/util/logging.hpp>
 #include <mbgl/util/platform.hpp>
 #include <mbgl/util/string.hpp>
+#include <mbgl/perf/runtime_metrics.hpp>
 
 #include <mapbox/cheap_ruler.hpp>
 #include <mapbox/geometry.hpp>
 #include <mapbox/geojson.hpp>
 
+#include <fstream>
+#include <string>
+#include <iostream>
+
 #if MBGL_USE_GLES2
 #define GLFW_INCLUDE_ES2
 #endif // MBGL_USE_GLES2
@@ -234,6 +239,18 @@ void GLFWView::onKey(GLFWwindow *window, int key, int /*scancode*/, int action,
         case GLFW_KEY_K:
             view->addRandomCustomPointAnnotations(1);
             break;
+        case GLFW_KEY_H:
+            MBGL_IF_TRACING(if (mbgl::util::Tracer::get().isCollectingData()) { \
+                mbgl::util::Tracer::get().setCollectData(false); \
+                std::string json = mbgl::util::Tracer::get().dumpAll(true); \
+                printf("%s\n", json.c_str()); \
+                                std::ofstream out("/tmp/mbgl_glfw_trace.json"); \
+                                out << json; \
+                                out.close(); \
+            } else { \
+                mbgl::util::Tracer::get().setCollectData(true); \
+            })
+            break;
         case GLFW_KEY_L:
             view->addRandomLineAnnotations(1);
             break;
-- 
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