From 4880a9d2f46208c70503513961cd36262cc187b4 Mon Sep 17 00:00:00 2001
From: Simon Wiesend <wiesendsi102436@th-nuernberg.de>
Date: Sun, 30 Nov 2025 10:34:01 +0100
Subject: [PATCH] fix: timers on Linux

On Linux the clock() function measures cpu time instead of wall time. This change uses the Apple code path for Linux.
---
 timer.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/timer.c b/timer.c
index fd8f6c1..2c80f33 100644
--- a/timer.c
+++ b/timer.c
@@ -1,6 +1,12 @@
 #include "timer.h"
 
-#if __APPLE__
+#ifdef __linux__
+// Defines strict posix compliance for CLOCK_MONOTONIC
+#define _POSIX_C_SOURCE 199309L
+#include <time.h>
+#endif
+
+#if __APPLE__ || __linux__
 #include <sys/time.h>
 static struct timespec start = {0, 0};
 
@@ -14,14 +20,15 @@ void startTimer()
 double stopTimer()
 {
     struct timespec end;
-    
+
     clock_gettime(CLOCK_MONOTONIC, &end);
 
     unsigned long long delta_us = (end.tv_sec - start.tv_sec) * 1000000 + (end.tv_nsec - start.tv_nsec) / 1000;
 
     double measuredSeconds = (double)delta_us / 1000000.;
 
-    if(start.tv_nsec > 0) {
+    if (start.tv_nsec > 0)
+    {
         start.tv_nsec = 0;
         start.tv_sec = 0;
     }
@@ -45,7 +52,7 @@ double stopTimer()
 {
     double measuredSeconds = (clock() - (double)startClocks) / CLOCKS_PER_SEC;
 
-    if(startClocks > 0)
+    if (startClocks > 0)
         startClocks = 0;
     else
         measuredSeconds = -1;