From c3bc5fb0ff2b68a5c69cad970cd762131c056ff2 Mon Sep 17 00:00:00 2001
From: Geoffrey McRae <geoff@hostfission.com>
Date: Fri, 9 Jul 2021 01:53:49 +1000
Subject: [PATCH] [client] app: collect render and frame timing information

---
 client/src/main.c | 24 +++++++++++++++++++++---
 client/src/main.h |  5 ++++-
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/client/src/main.c b/client/src/main.c
index 0159b521..a78ae3d8 100644
--- a/client/src/main.c
+++ b/client/src/main.c
@@ -149,11 +149,15 @@ static int renderThread(void * unused)
     }
     LG_UNLOCK(g_state.lgrLock);
 
+    const uint64_t t      = nanotime();
+    const uint64_t delta  = t - g_state.lastRenderTime;
+    g_state.lastRenderTime = t;
+    const float fdelta = (float)delta / 1000000.0f;
+    ringbuffer_push(g_state.renderTimings, &fdelta);
+
     if (g_state.showFPS)
     {
-      const uint64_t t    = nanotime();
-      g_state.renderTime   += t - g_state.lastFrameTime;
-      g_state.lastFrameTime = t;
+      g_state.renderTime   += delta;
       ++g_state.renderCount;
 
       if (g_state.renderTime > 1e9)
@@ -594,6 +598,12 @@ int main_frameThread(void * unused)
       g_state.autoIdleInhibitState = frame->blockScreensaver;
     }
 
+    const uint64_t t      = nanotime();
+    const uint64_t delta  = t - g_state.lastFrameTime;
+    g_state.lastFrameTime = t;
+    const float fdelta = (float)delta / 1000000.0f;
+    ringbuffer_push(g_state.frameTimings, &fdelta);
+
     atomic_fetch_add_explicit(&g_state.frameCount, 1, memory_order_relaxed);
     lgSignalEvent(e_frame);
     lgmpClientMessageDone(queue);
@@ -697,6 +707,10 @@ static int lg_run(void)
   ImFontAtlas_GetTexDataAsRGBA32(g_state.io->Fonts, &text_pixels,
       &text_w, &text_h, NULL);
 
+  // initialize metrics ringbuffers
+  g_state.renderTimings = ringbuffer_new(256, sizeof(float));
+  g_state.frameTimings  = ringbuffer_new(256, sizeof(float));
+
   // search for the best displayserver ops to use
   for(int i = 0; i < LG_DISPLAYSERVER_COUNT; ++i)
     if (LG_DisplayServers[i]->probe())
@@ -1064,6 +1078,10 @@ static void lg_shutdown(void)
 
   ivshmemClose(&g_state.shm);
 
+  // free metrics ringbuffers
+  ringbuffer_free(&g_state.renderTimings);
+  ringbuffer_free(&g_state.frameTimings );
+
   igDestroyContext(NULL);
 }
 
diff --git a/client/src/main.h b/client/src/main.h
index 9c7c239b..65781c2e 100644
--- a/client/src/main.h
+++ b/client/src/main.h
@@ -29,6 +29,7 @@
 #include "common/types.h"
 #include "common/ivshmem.h"
 #include "common/locking.h"
+#include "common/ringbuffer.h"
 
 #include "spice/spice.h"
 #include <lgmp/client.h>
@@ -96,9 +97,11 @@ struct AppState
   atomic_uint_least64_t frameTime;
   uint64_t              lastFrameTime;
   uint64_t              renderTime;
+  uint64_t              lastRenderTime;
   atomic_uint_least64_t frameCount;
   uint64_t              renderCount;
-
+  RingBuffer            renderTimings;
+  RingBuffer            frameTimings;
 
   uint64_t resizeTimeout;
   bool     resizeDone;