From 164d4852fa82111277d4e12421046aac3dfe55ba Mon Sep 17 00:00:00 2001
From: PixelyIon <pixelyion@protonmail.com>
Date: Sun, 10 Apr 2022 13:26:02 +0530
Subject: [PATCH] Sleep-loop rather than abort during termination

We don't want to actually exit the process as it'll automatically be restarted gracefully due to a timeout after being unable to exit within a fixed duration so we just want to infinite sleep during termination. This should fix issues where exiting any game would cause the app to force close after some time as exception signal handling would fail in the background, the app should stay open now and automatically restart itself when another game is loaded in.
---
 app/src/main/cpp/skyline/common/signal.cpp | 30 ++++++++++------------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/app/src/main/cpp/skyline/common/signal.cpp b/app/src/main/cpp/skyline/common/signal.cpp
index d5bccc36..526630eb 100644
--- a/app/src/main/cpp/skyline/common/signal.cpp
+++ b/app/src/main/cpp/skyline/common/signal.cpp
@@ -14,7 +14,12 @@ namespace skyline::signal {
         std::rethrow_exception(SignalExceptionPtr);
     }
 
-    std::terminate_handler terminateHandler{};
+    void SleepTillExit() {
+        // We don't want to actually exit the process ourselves as it'll automatically be restarted gracefully due to a timeout after being unable to exit within a fixed duration
+        Logger::EmulationContext.TryFlush(); // We want to attempt to flush logs before exiting
+        while (true)
+            sleep(std::numeric_limits<int>::max()); // We just trigger the timeout wait by sleeping forever
+    }
 
     inline StackFrame *SafeFrameRecurse(size_t depth, StackFrame *frame) {
         if (frame) {
@@ -22,17 +27,17 @@ namespace skyline::signal {
                 if (frame->lr && frame->next)
                     frame = frame->next;
                 else
-                    terminateHandler();
+                    SleepTillExit();
             }
         } else {
-            terminateHandler();
+            SleepTillExit();
         }
         return frame;
     }
 
     void TerminateHandler() {
         auto exception{std::current_exception()};
-        if (terminateHandler && exception && exception == SignalExceptionPtr) {
+        if (exception && exception == SignalExceptionPtr) {
             StackFrame *frame;
             asm("MOV %0, FP" : "=r"(frame));
             frame = SafeFrameRecurse(2, frame); // We unroll past 'std::terminate'
@@ -56,17 +61,14 @@ namespace skyline::signal {
                         frame = SafeFrameRecurse(2, lookupFrame);
                         hasAdvanced = true;
                     } else {
-                        Logger::EmulationContext.TryFlush();
-                        terminateHandler(); // We presumably have no exception handlers left on the stack to consume the exception, it's time to quit
+                        SleepTillExit(); // We presumably have no exception handlers left on the stack to consume the exception, it's time to quit
                     }
                 }
                 lookupFrame = lookupFrame->next;
             }
 
-            if (!frame->next) {
-                Logger::EmulationContext.TryFlush(); // We want to attempt to flush all logs before quitting
-                terminateHandler(); // We don't know the frame's stack boundaries, the only option is to quit
-            }
+            if (!frame->next)
+                SleepTillExit(); // We don't know the frame's stack boundaries, the only option is to quit
 
             asm("MOV SP, %x0\n\t" // Stack frame is the first item on a function's stack, it's used to calculate calling function's stack pointer
                 "MOV LR, %x1\n\t"
@@ -76,7 +78,7 @@ namespace skyline::signal {
 
             __builtin_unreachable();
         } else {
-            terminateHandler();
+            SleepTillExit(); // We don't want to delegate to the older terminate handler as it might cause an exit
         }
     }
 
@@ -97,11 +99,7 @@ namespace skyline::signal {
         SignalExceptionPtr = std::make_exception_ptr(signalException);
         context->uc_mcontext.pc = reinterpret_cast<u64>(&ExceptionThrow);
 
-        auto handler{std::get_terminate()};
-        if (handler != TerminateHandler) {
-            terminateHandler = handler;
-            std::set_terminate(TerminateHandler);
-        }
+        std::set_terminate(TerminateHandler);
 
         Logger::EmulationContext.TryFlush(); // We want to attempt to flush all logs in case exception handling fails and infloops
     }