From 47950ee21673f32dca172eb16bb68b7e6de61eb7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Florian=20N=C3=BCcke?= <florian@nuecke.de>
Date: Wed, 16 Sep 2020 12:03:01 +0200
Subject: [PATCH] Synchronously read board output instead of thread for
 determinism in benchmark.

---
 src/main/java/li/cil/circuity/Main.java | 61 ++++++-------------------
 1 file changed, 14 insertions(+), 47 deletions(-)

diff --git a/src/main/java/li/cil/circuity/Main.java b/src/main/java/li/cil/circuity/Main.java
index 79ff4648..9c9a1eb3 100644
--- a/src/main/java/li/cil/circuity/Main.java
+++ b/src/main/java/li/cil/circuity/Main.java
@@ -20,16 +20,12 @@ public final class Main {
         final String firmware = "C:\\Users\\fnuecke\\Documents\\Repositories\\Circuity-1.15\\buildroot\\fw_jump.bin";
         final String kernel = "C:\\Users\\fnuecke\\Documents\\Repositories\\Circuity-1.15\\buildroot\\Image";
 
-        final UARTReader reader = new UARTReader(board);
-        final Thread thread = new Thread(reader);
-        thread.start();
-
         System.out.println("Waiting for profiler...");
         Thread.sleep(5 * 1000);
         System.out.println("Starting!");
 
         final long cyclesPerRun = 300_000_000;
-        final int cyclesPerStep = 10_000;
+        final int cyclesPerStep = 1_000;
         final int hz = 50_000_000;
 
         final int samples = 10;
@@ -38,28 +34,36 @@ public final class Main {
         int accRunDuration = 0;
 
         final R5CPU cpu = board.getCpu();
+        final StringBuilder sb = new StringBuilder(16 * 1024);
 
         for (int i = 0; i < 10; i++) {
+            board.reset();
             loadProgramFile(memory, 0, kernel);
             loadProgramFile(rom, 0, firmware);
-            cpu.reset();
+            sb.setLength(0);
 
             final long runStart = System.currentTimeMillis();
 
+            final long limit = cpu.getTime() + cyclesPerRun;
             int remaining = 0;
-            while (cpu.getTime() < cyclesPerRun) {
+            while (cpu.getTime() < limit) {
                 final long stepStart = System.currentTimeMillis();
 
                 remaining += hz;
                 while (remaining > 0) {
                     board.step(cyclesPerStep);
                     remaining -= cyclesPerStep;
+
+                    int value;
+                    while ((value = board.readValue()) != -1) {
+                        sb.append((char) value);
+                    }
                 }
 
                 final long stepDuration = System.currentTimeMillis() - stepStart;
                 final long sleep = 1000 - stepDuration;
                 if (sleep > 0) {
-//                Thread.sleep(sleep);
+//                    Thread.sleep(sleep);
                 } else {
                     System.out.println("Running behind by " + (-sleep) + "ms...");
                 }
@@ -70,16 +74,14 @@ public final class Main {
             minRunDuration = Integer.min(minRunDuration, runDuration);
             maxRunDuration = Integer.max(maxRunDuration, runDuration);
 
+            System.out.print(sb.toString());
+
             System.out.printf("\n\ntime: %.2fs\n", runDuration / 1000.0);
         }
 
-        reader.stop();
-
         final int avgDuration = accRunDuration / samples;
         System.out.printf("\n\ntimes: min=%.2fs, max=%.2fs, avg=%.2fs\n",
                 minRunDuration / 1000.0, maxRunDuration / 1000.0, avgDuration / 1000.0);
-
-        thread.join();
     }
 
     private static void loadProgramFile(final PhysicalMemory memory, int address, final String path) throws Exception {
@@ -90,39 +92,4 @@ public final class Main {
             }
         }
     }
-
-    private static final class UARTReader implements Runnable {
-        private final R5Board board;
-        private boolean keepRunning = true;
-
-        private UARTReader(final R5Board board) {
-            this.board = board;
-        }
-
-        public void stop() {
-            keepRunning = false;
-        }
-
-        @Override
-        public void run() {
-            try {
-                final StringBuilder sb = new StringBuilder();
-                while (keepRunning) {
-                    final int i = board.readValue();
-                    if (i >= 0) {
-                        final char ch = (char) i;
-                        sb.append(ch);
-                        if (ch == '\r' || ch == '\n') {
-                            final String line = sb.toString();
-                            System.out.print(line);
-                            sb.setLength(0);
-                        }
-                    }
-                    Thread.yield();
-                }
-            } catch (final Throwable t) {
-                t.printStackTrace();
-            }
-        }
-    }
 }