Fix Native-Initiated Exiting

app/src/main/cpp/emu_jni.cpp

@@ -2,8 +2,8 @@
 // Copyright © 2020 Skyline Team and Contributors (https://github.com/skyline-emu/)
 
 #include <csignal>
+#include <pthread.h>
 #include <unistd.h>
-#include <sys/resource.h>
 #include <android/log.h>
 #include "skyline/loader/loader.h"
 #include "skyline/common.h"
@@ -21,8 +21,7 @@ std::weak_ptr<skyline::gpu::GPU> GpuWeak;
 std::weak_ptr<skyline::input::Input> InputWeak;
 
 extern "C" JNIEXPORT void Java_emu_skyline_EmulationActivity_executeApplication(JNIEnv *env, jobject instance, jstring romUriJstring, jint romType, jint romFd, jint preferenceFd, jstring appFilesPathJstring) {
-    Fps = 0;
-    FrameTime = 0;
+    Fps = FrameTime = 0;
 
     pthread_setname_np(pthread_self(), "EmuMain");
 
@@ -65,31 +64,39 @@ extern "C" JNIEXPORT void Java_emu_skyline_EmulationActivity_executeApplication(
     close(romFd);
 }
 
-extern "C" JNIEXPORT void Java_emu_skyline_EmulationActivity_stopEmulation(JNIEnv *, jobject) {
+extern "C" JNIEXPORT jboolean Java_emu_skyline_EmulationActivity_stopEmulation(JNIEnv *, jobject) {
     auto os{OsWeak.lock()};
-    while (!os)
-        os = OsWeak.lock();
+    if (!os)
+        return false;
     auto process{os->state.process};
-    while (!process) {
-        __sync_synchronize();
-        process = os->state.process;
-    }
+    if (!process)
+        return false;
     process->Kill(true, false, true);
+    return true;
 }
 
-extern "C" JNIEXPORT void Java_emu_skyline_EmulationActivity_setSurface(JNIEnv *, jobject, jobject surface) {
+extern "C" JNIEXPORT jboolean Java_emu_skyline_EmulationActivity_setSurface(JNIEnv *, jobject, jobject surface) {
     auto gpu{GpuWeak.lock()};
-    while (!gpu)
-        gpu = GpuWeak.lock();
+    if (!gpu)
+        return false;
     gpu->presentation.UpdateSurface(surface);
+    return true;
 }
 
-extern "C" JNIEXPORT jint Java_emu_skyline_EmulationActivity_getFps(JNIEnv *, jobject) {
-    return Fps;
-}
+extern "C" JNIEXPORT void Java_emu_skyline_EmulationActivity_updatePerformanceStatistics(JNIEnv *env, jobject thiz) {
+    static jclass clazz{};
+    if (!clazz)
+        clazz = env->GetObjectClass(thiz);
 
-extern "C" JNIEXPORT jfloat Java_emu_skyline_EmulationActivity_getFrametime(JNIEnv *, jobject) {
-    return static_cast<float>(FrameTime) / 100;
+    static jfieldID fpsField{};
+    if (!fpsField)
+        fpsField = env->GetFieldID(clazz, "fps", "I");
+    env->SetIntField(thiz, fpsField, Fps);
+
+    static jfieldID frametimeField{};
+    if (!frametimeField)
+        frametimeField = env->GetFieldID(clazz, "frametime", "F");
+    env->SetFloatField(thiz, frametimeField, static_cast<float>(FrameTime) / 100);
 }
 
 extern "C" JNIEXPORT void JNICALL Java_emu_skyline_EmulationActivity_setController(JNIEnv *, jobject, jint index, jint type, jint partnerIndex) {

app/src/main/cpp/skyline/common.h

@@ -132,7 +132,7 @@ namespace skyline {
         }
 
         /**
-         * @brief A way to implicitly convert a pointer to size_t and leave it unaffected if it isn't a pointer
+         * @brief A way to implicitly convert a pointer to uintptr_t and leave it unaffected if it isn't a pointer
          */
         template<class T>
         T PointerValue(T item) {
@@ -144,6 +144,17 @@ namespace skyline {
             return reinterpret_cast<uintptr_t>(item);
         }
 
+        /**
+         * @brief A way to implicitly convert an integral to a pointer, if the return type is a pointer
+         */
+        template<class Return, class T>
+        Return ValuePointer(T item) {
+            if constexpr (std::is_pointer<Return>::value)
+                return reinterpret_cast<Return>(item);
+            else
+                return item;
+        }
+
         /**
          * @return The value aligned up to the next multiple
          * @note The multiple needs to be a power of 2
@@ -151,7 +162,7 @@ namespace skyline {
         template<typename TypeVal, typename TypeMul>
         constexpr TypeVal AlignUp(TypeVal value, TypeMul multiple) {
             multiple--;
-            return (PointerValue(value) + multiple) & ~(multiple);
+            return ValuePointer<TypeVal>((PointerValue(value) + multiple) & ~(multiple));
         }
 
         /**
@@ -160,7 +171,7 @@ namespace skyline {
          */
         template<typename TypeVal, typename TypeMul>
         constexpr TypeVal AlignDown(TypeVal value, TypeMul multiple) {
-            return PointerValue(value) & ~(multiple - 1);
+            return ValuePointer<TypeVal>(PointerValue(value) & ~(multiple - 1));
         }
 
         /**

app/src/main/cpp/skyline/nce.cpp

@@ -59,7 +59,7 @@ namespace skyline::nce {
                 constexpr u16 instructionCount{20}; // The amount of previous instructions to print
                 auto offset{ctx.pc - (instructionCount * sizeof(u32)) + (2 * sizeof(u32))};
                 span instructions(reinterpret_cast<u32 *>(offset), instructionCount);
-                if (mprotect(instructions.data(), instructions.size_bytes(), PROT_READ | PROT_WRITE | PROT_EXEC) == 0) {
+                if (mprotect(util::AlignDown(instructions.data(), PAGE_SIZE), util::AlignUp(instructions.size_bytes(), PAGE_SIZE), PROT_READ | PROT_WRITE | PROT_EXEC) == 0) {
                     for (auto &instruction : instructions) {
                         instruction = __builtin_bswap32(instruction);
 
@@ -75,7 +75,7 @@ namespace skyline::nce {
                     state.logger->Debug("Process Trace:{}", trace);
                     state.logger->Debug("Raw Instructions: 0x{}", raw);
                 } else {
-                    cpuContext += fmt::format("\nPC: 0x{:X}", ctx.pc);
+                    cpuContext += fmt::format("\nPC: 0x{:X} ('mprotect' failed with '{}')", ctx.pc, strerror(errno));
                 }
 
                 if (ctx.fault_address)
@@ -85,7 +85,7 @@ namespace skyline::nce {
                     cpuContext += fmt::format("\nStack Pointer: 0x{:X}", ctx.sp);
 
                 for (u8 index{}; index < ((sizeof(mcontext_t::regs) / sizeof(u64)) - 2); index += 2)
-                    cpuContext += fmt::format("\n{}X{}: 0x{:<16X} {}{}: 0x{:X}", index < 10 ? ' ' : '\0', index, ctx.regs[index], index < 10 ? ' ' : '\0', index + 1, ctx.regs[index]);
+                    cpuContext += fmt::format("\n{}X{}: 0x{:<16X} {}{}: 0x{:X}", index < 10 ? ' ' : '\0', index, ctx.regs[index], index < 10 ? 'X' : '\0', index + 1, ctx.regs[index]);
 
                 state.logger->Debug("CPU Context:{}", cpuContext);
             }

app/src/main/java/emu/skyline/EmulationActivity.kt

@@ -68,26 +68,25 @@ class EmulationActivity : AppCompatActivity(), SurfaceHolder.Callback, View.OnTo
     private external fun executeApplication(romUri : String, romType : Int, romFd : Int, preferenceFd : Int, appFilesPath : String)
 
     /**
-     * Terminate of all emulator threads and cause [emulationThread] to return
+     * @return If it successfully caused the [emulationThread] to gracefully stop
      */
-    private external fun stopEmulation()
+    private external fun stopEmulation() : Boolean
 
     /**
      * This sets the surface object in libskyline to the provided value, emulation is halted if set to null
      *
      * @param surface The value to set surface to
+     * @return If the value was successfully set
      */
-    private external fun setSurface(surface : Surface?)
+    private external fun setSurface(surface : Surface?) : Boolean
+
+    var fps : Int = 0
+    var frametime : Float = 0.0f
 
     /**
-     * This returns the current FPS of the application
+     * Writes the current performance statistics into [fps] and [frametime] fields
      */
-    private external fun getFps() : Int
-
-    /**
-     * This returns the current frame-time of the application
-     */
-    private external fun getFrametime() : Float
+    private external fun updatePerformanceStatistics()
 
     /**
      * This initializes a guest controller in libskyline
@@ -170,7 +169,10 @@ class EmulationActivity : AppCompatActivity(), SurfaceHolder.Callback, View.OnTo
         emulationThread = Thread {
             executeApplication(rom.toString(), romType, romFd.detachFd(), preferenceFd.detachFd(), applicationContext.filesDir.canonicalPath + "/")
             if (shouldFinish)
-                runOnUiThread { finish() }
+                runOnUiThread {
+                    emulationThread.join()
+                    finish()
+                }
         }
 
         emulationThread.start()
@@ -203,7 +205,8 @@ class EmulationActivity : AppCompatActivity(), SurfaceHolder.Callback, View.OnTo
         if (settings.perfStats) {
             perf_stats.postDelayed(object : Runnable {
                 override fun run() {
-                    perf_stats.text = "${getFps()} FPS\n${getFrametime()}ms"
+                    updatePerformanceStatistics()
+                    perf_stats.text = "$fps FPS\n${frametime}ms"
                     perf_stats.postDelayed(this, 250)
                 }
             }, 250)
@@ -234,8 +237,9 @@ class EmulationActivity : AppCompatActivity(), SurfaceHolder.Callback, View.OnTo
         super.onNewIntent(intent)
         shouldFinish = false
 
-        stopEmulation()
-        emulationThread.join()
+        while (emulationThread.isAlive)
+            if (stopEmulation())
+                emulationThread.join()
 
         shouldFinish = true
 
@@ -246,8 +250,9 @@ class EmulationActivity : AppCompatActivity(), SurfaceHolder.Callback, View.OnTo
         super.onDestroy()
         shouldFinish = false
 
-        stopEmulation()
-        emulationThread.join()
+        while (emulationThread.isAlive)
+            if (stopEmulation())
+                emulationThread.join()
 
         vibrators.forEach { (_, vibrator) -> vibrator.cancel() }
         vibrators.clear()
@@ -259,7 +264,9 @@ class EmulationActivity : AppCompatActivity(), SurfaceHolder.Callback, View.OnTo
     override fun surfaceCreated(holder : SurfaceHolder) {
         Log.d(Tag, "surfaceCreated Holder: $holder")
         surface = holder.surface
-        setSurface(surface)
+        while (emulationThread.isAlive)
+            if (setSurface(surface))
+                return
     }
 
     /**
@@ -275,7 +282,9 @@ class EmulationActivity : AppCompatActivity(), SurfaceHolder.Callback, View.OnTo
     override fun surfaceDestroyed(holder : SurfaceHolder) {
         Log.d(Tag, "surfaceDestroyed Holder: $holder")
         surface = null
-        setSurface(surface)
+        while (emulationThread.isAlive)
+            if (setSurface(surface))
+                return
     }
 
     /**