From 18c1c39d5e3c096fdcfafa38487f735501c543fb Mon Sep 17 00:00:00 2001
From: Yuri Kunde Schlesner <yuriks@yuriks.net>
Date: Tue, 25 Aug 2015 23:47:29 -0300
Subject: [PATCH] SVC: Advance time when calling GetSystemTick to escape
busy-wait loops
Cubic Ninja waited for the frame to end by spinning on a loop calling
GetSystemTick while doing nothing else. Since GetSystemTick doesn't
cause a reschedule (which advances time), this meant that very little
emulated time would pass inside that loop, causing the game to spend
most of the frame burning away CPU.
---
src/core/hle/svc.cpp | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/src/core/hle/svc.cpp b/src/core/hle/svc.cpp
index 19f750d727..45d5f3c5d6 100644
--- a/src/core/hle/svc.cpp
+++ b/src/core/hle/svc.cpp
@@ -755,7 +755,10 @@ static void SleepThread(s64 nanoseconds) {
/// This returns the total CPU ticks elapsed since the CPU was powered-on
static s64 GetSystemTick() {
- return (s64)CoreTiming::GetTicks();
+ s64 result = CoreTiming::GetTicks();
+ // Advance time to defeat dumb games (like Cubic Ninja) that busy-wait for the frame to end.
+ Core::g_app_core->AddTicks(150); // Measured time between two calls on a 9.2 o3DS with Ninjhax 1.1b
+ return result;
}
/// Creates a memory block at the specified address with the specified permissions and size