wip: prevent reusing startTimestamp

Author: not-matthias

testing/testing/benchmark.go

@@ -164,6 +164,7 @@ func (b *B) StartTimer() {
 		b.timerOn = true
 		// b.loop.i &^= loopPoisonTimer
 
+		// Capture fresh start timestamp for this timing session
 		b.codspeed.startTimestamp = capi.CurrentTimestamp()
 	}
 }
@@ -182,14 +183,17 @@ func (b *B) StopTimer() {
 		// If we hit B.Loop with the timer stopped, fail.
 		// b.loop.i |= loopPoisonTimer
 
+		// Only accumulate timestamps if we have a valid start timestamp
+		if b.codspeed.startTimestamp == 0 {
+			panic(fmt.Sprintf("StopTimer called without StartTimer for benchmark %s", b.name))
+		}
+
 		// Accumulate timestamps for batch submission instead of immediate hook call
 		b.codspeed.accumulatedStartTimestamps = append(b.codspeed.accumulatedStartTimestamps, b.codspeed.startTimestamp)
 		b.codspeed.accumulatedEndTimestamps = append(b.codspeed.accumulatedEndTimestamps, endTimestamp)
 
-		// Debug log every 10000 accumulated timestamps to detect potential memory issues
-		if len(b.codspeed.accumulatedStartTimestamps)%10000 == 0 && len(b.codspeed.accumulatedStartTimestamps) > 0 {
-			fmt.Printf("DEBUG: Accumulated %d timestamp pairs for benchmark %s\n", len(b.codspeed.accumulatedStartTimestamps), b.name)
-		}
+		// Reset startTimestamp to prevent reuse
+		b.codspeed.startTimestamp = 0
 
 		// For b.N loops: This will be called in runN which sets b.N to the number of iterations.
 		// For b.Loop() loops: loopSlowPath sets b.N to 0 to prevent b.N loops within b.Loop. However, since