Feat[launcher]: user facing dialog when exiting with a signal

app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/ExitActivity.java

@@ -4,7 +4,6 @@
 
 import android.annotation.SuppressLint;
 import android.content.Context;
-import android.content.DialogInterface;
 import android.content.Intent;
 import android.os.Bundle;
 
@@ -20,22 +19,26 @@ public class ExitActivity extends AppCompatActivity {
     @Override
     public void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        int code = -1;
+        int code = -1; boolean isSignal = false;
         Bundle extras = getIntent().getExtras();
         if(extras != null) {
             code = extras.getInt("code",-1);
+            isSignal = extras.getBoolean("isSignal", false);
         }
 
+        int message = isSignal ? R.string.mcn_signal_title : R.string.mcn_exit_title;
+
         new AlertDialog.Builder(this)
-                .setMessage(getString(R.string.mcn_exit_title,code))
+                .setMessage(getString(message,code))
                 .setPositiveButton(R.string.main_share_logs, (dialog, which) -> shareLog(this))
                 .setOnDismissListener(dialog -> ExitActivity.this.finish())
                 .show();
     }
 
-    public static void showExitMessage(Context ctx, int code) {
+    public static void showExitMessage(Context ctx, int code, boolean isSignal) {
         Intent i = new Intent(ctx,ExitActivity.class);
         i.putExtra("code",code);
+        i.putExtra("isSignal", isSignal);
         i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
         i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
         ctx.startActivity(i);

app_pojavlauncher/src/main/java/net/kdt/pojavlaunch/utils/JREUtils.java

@@ -572,6 +572,5 @@ public static int getDetectedVersion() {
     static {
         System.loadLibrary("pojavexec");
         System.loadLibrary("pojavexec_awt");
-        System.loadLibrary("istdio");
     }
 }

app_pojavlauncher/src/main/jni/Android.mk

@@ -20,12 +20,15 @@ LOCAL_SRC_FILES := tinywrapper/main.c tinywrapper/string_utils.c
 LOCAL_C_INCLUDES := $(LOCAL_PATH)/tinywrapper
 include $(BUILD_SHARED_LIBRARY)
 
+$(call import-module,prefab/bytehook)
+LOCAL_PATH := $(HERE_PATH)
 
 include $(CLEAR_VARS)
 # Link GLESv2 for test
 LOCAL_LDLIBS := -ldl -llog -landroid
 # -lGLESv2
 LOCAL_MODULE := pojavexec
+LOCAL_SHARED_LIBRARIES := bytehook
 # LOCAL_CFLAGS += -DDEBUG
 # -DGLES_TEST
 LOCAL_SRC_FILES := \
@@ -40,6 +43,7 @@ LOCAL_SRC_FILES := \
     input_bridge_v3.c \
     jre_launcher.c \
     utils.c \
+    stdio_is.c \
     driver_helper/nsbypass.c
 
 ifeq ($(TARGET_ARCH_ABI),arm64-v8a)
@@ -56,16 +60,6 @@ LOCAL_LDFLAGS := -z global
 include $(BUILD_SHARED_LIBRARY)
 #endif
 
-$(call import-module,prefab/bytehook)
-LOCAL_PATH := $(HERE_PATH)
-
-include $(CLEAR_VARS)
-LOCAL_MODULE := istdio
-LOCAL_SHARED_LIBRARIES := bytehook
-LOCAL_SRC_FILES := \
-    stdio_is.c
-include $(BUILD_SHARED_LIBRARY)
-
 include $(CLEAR_VARS)
 LOCAL_MODULE := pojavexec_awt
 LOCAL_SRC_FILES := \

app_pojavlauncher/src/main/jni/jre_launcher.c

@@ -65,6 +65,62 @@ typedef jint JLI_Launch_func(int argc, char ** argv, /* main argc, argc */
         jint ergo                               /* ergonomics class policy */
 );
 
+struct {
+    sigset_t tracked_sigset;
+    int pipe[2];
+} abrt_waiter_data;
+
+_Noreturn extern void nominal_exit(int code, bool is_signal);
+
+_Noreturn static void* abrt_waiter_thread(void* extraArg) {
+    // Don't allow this thread to receive signals this thread is tracking.
+    // We should only receive them externally.
+    pthread_sigmask(SIG_BLOCK, &abrt_waiter_data.tracked_sigset, NULL);
+    int signal;
+    // Block for reading the signal ID until it arrives
+    read(abrt_waiter_data.pipe[0], &signal, sizeof(int));
+    // Die
+    nominal_exit(signal, true);
+}
+
+_Noreturn static void abrt_waiter_handler(int signal) {
+    // Write the final signal into the pipe and block forever.
+    write(abrt_waiter_data.pipe[1], &signal, sizeof(int));
+    while(1) {};
+};
+
+static void abrt_waiter_setup() {
+    // Only abort on SIGABRT as the JVM either emits SIGABRT or SIGKILL (which we can't catch)
+    // when a fatal crash occurs. Still, keep expandability if we would want to add more
+    // user-friendly fatal signals in the future.
+    const static int tracked_signals[] = {SIGABRT};
+    const static int ntracked = (sizeof(tracked_signals) / sizeof(tracked_signals[0]));
+    struct sigaction sigactions[ntracked];
+    sigemptyset(&abrt_waiter_data.tracked_sigset);
+    for(size_t i = 0; i < ntracked; i++) {
+        sigaddset(&abrt_waiter_data.tracked_sigset, tracked_signals[i]);
+        sigactions[i].sa_handler = abrt_waiter_handler;
+    }
+    if(pipe(abrt_waiter_data.pipe) != 0) {
+        printf("Failed to set up aborter pipe: %s\n", strerror(errno));
+        return;
+    }
+    pthread_t waiter_thread; int result;
+    if((result = pthread_create(&waiter_thread, NULL, abrt_waiter_thread, NULL)) != 0) {
+        printf("Failed to start up waiter thread: %s", strerror(result));
+        for(int i = 0; i < 2; i++) close(abrt_waiter_data.pipe[i]);
+        return;
+    }
+    // Only set the sigactions *after* we have already set up the pipe and the thread.
+    for(size_t i = 0; i < ntracked; i++) {
+        if(sigaction(tracked_signals[i], &sigactions[i], NULL) != 0) {
+            // Not returning here because we may have set some handlers successfully.
+            // Some handling is better than no handling.
+            printf("Failed to set signal hander for signal %i: %s", i, strerror(errno));
+        }
+    }
+}
+
 static jint launchJVM(int margc, char** margv) {
    void* libjli = dlopen("libjli.so", RTLD_LAZY | RTLD_GLOBAL);
 
@@ -80,6 +136,8 @@ static jint launchJVM(int margc, char** margv) {
        else clean_sa.sa_handler = SIG_DFL;
        sigaction(sigid, &clean_sa, NULL);
    }
+   // Set up the thread that will abort the launcher with an user-facing dialog on a signal.
+   abrt_waiter_setup();
 
    // Boardwalk: silence
    // LOGD("JLI lib = %x", (int)libjli);

app_pojavlauncher/src/main/jni/stdio_is.c

@@ -9,6 +9,7 @@
 #include <errno.h>
 #include <stdlib.h>
 #include <bytehook.h>
+#include <environ/environ.h>
 
 //
 // Created by maks on 17.02.21.
@@ -19,7 +20,6 @@ static volatile jclass exitTrap_exitClass;
 static volatile jmethodID exitTrap_staticMethod;
 static JavaVM *exitTrap_jvm;
 
-static JavaVM *stdiois_jvm;
 static int pfd[2];
 static pthread_t logger;
 static jmethodID logger_onEventLogged;
@@ -37,19 +37,11 @@ static bool recordBuffer(char* buf, ssize_t len) {
     return true;
 }
 
-JNIEXPORT jint JNI_OnLoad(JavaVM* vm, __attribute((unused)) void* reserved) {
-    stdiois_jvm = vm;
-    JNIEnv *env;
-    (*vm)->GetEnv(vm, (void**)&env, JNI_VERSION_1_4);
-    jclass eventLogListener = (*env)->FindClass(env, "net/kdt/pojavlaunch/Logger$eventLogListener");
-    logger_onEventLogged = (*env)->GetMethodID(env, eventLogListener, "onEventLogged", "(Ljava/lang/String;)V");
-    return JNI_VERSION_1_4;
-}
-
 static void *logger_thread() {
     JNIEnv *env;
     jstring writeString;
-    (*stdiois_jvm)->AttachCurrentThread(stdiois_jvm, &env, NULL);
+    JavaVM* dvm = pojav_environ->dalvikJavaVMPtr;
+    (*dvm)->AttachCurrentThread(dvm, &env, NULL);
     ssize_t  rsize;
     char buf[2050];
     while((rsize = read(pfd[0], buf, sizeof(buf)-1)) > 0) {
@@ -64,7 +56,7 @@ static void *logger_thread() {
             (*env)->DeleteLocalRef(env, writeString);
         }
     }
-    (*stdiois_jvm)->DetachCurrentThread(stdiois_jvm);
+    (*dvm)->DetachCurrentThread(dvm);
     return NULL;
 }
 JNIEXPORT void JNICALL
@@ -74,6 +66,10 @@ Java_net_kdt_pojavlaunch_Logger_begin(JNIEnv *env, __attribute((unused)) jclass
         latestlog_fd = -1;
         close(localfd);
     }
+    if(logger_onEventLogged == NULL) {
+        jclass eventLogListener = (*env)->FindClass(env, "net/kdt/pojavlaunch/Logger$eventLogListener");
+        logger_onEventLogged = (*env)->GetMethodID(env, eventLogListener, "onEventLogged", "(Ljava/lang/String;)V");
+    }
     jclass ioeClass = (*env)->FindClass(env, "java/io/IOException");
 
 
@@ -109,7 +105,7 @@ Java_net_kdt_pojavlaunch_Logger_begin(JNIEnv *env, __attribute((unused)) jclass
 
 typedef void (*exit_func)(int);
 
-_Noreturn static void nominal_exit(int code) {
+_Noreturn void nominal_exit(int code, bool is_signal) {
     JNIEnv *env;
     jint errorCode = (*exitTrap_jvm)->GetEnv(exitTrap_jvm, (void**)&env, JNI_VERSION_1_6);
     if(errorCode == JNI_EDETACHED) {
@@ -124,7 +120,7 @@ _Noreturn static void nominal_exit(int code) {
     if(code != 0) {
         // Exit code 0 is pretty established as "eh it's fine"
         // so only open the GUI if the code is != 0
-        (*env)->CallStaticVoidMethod(env, exitTrap_exitClass, exitTrap_staticMethod, exitTrap_ctx, code);
+        (*env)->CallStaticVoidMethod(env, exitTrap_exitClass, exitTrap_staticMethod, exitTrap_ctx, code, is_signal);
     }
     // Delete the reference, not gonna need 'em later anyway
     (*env)->DeleteGlobalRef(env, exitTrap_ctx);
@@ -155,7 +151,7 @@ static void custom_exit(int code) {
     }
     exit_tripped = true;
     // Perform a nominal exit, as we expect.
-    nominal_exit(code);
+    nominal_exit(code, false);
     BYTEHOOK_POP_STACK();
 }
 
@@ -165,14 +161,14 @@ static void custom_atexit() {
         return;
     }
     exit_tripped = true;
-    nominal_exit(0);
+    nominal_exit(0, false);
 }
 
 JNIEXPORT void JNICALL Java_net_kdt_pojavlaunch_utils_JREUtils_setupExitTrap(JNIEnv *env, __attribute((unused)) jclass clazz, jobject context) {
     exitTrap_ctx = (*env)->NewGlobalRef(env,context);
     (*env)->GetJavaVM(env,&exitTrap_jvm);
     exitTrap_exitClass = (*env)->NewGlobalRef(env,(*env)->FindClass(env,"net/kdt/pojavlaunch/ExitActivity"));
-    exitTrap_staticMethod = (*env)->GetStaticMethodID(env,exitTrap_exitClass,"showExitMessage","(Landroid/content/Context;I)V");
+    exitTrap_staticMethod = (*env)->GetStaticMethodID(env,exitTrap_exitClass,"showExitMessage","(Landroid/content/Context;IZ)V");
 
     if(bytehook_init(BYTEHOOK_MODE_AUTOMATIC, false) == BYTEHOOK_STATUS_CODE_OK) {
         bytehook_hook_all(NULL,

app_pojavlauncher/src/main/res/values/strings.xml

@@ -93,6 +93,7 @@
 
     <!-- MainActivity: strings -->
     <string name="mcn_exit_title">Application/Game exited with code %d, check latestlog.txt for more details.</string>
+    <string name="mcn_signal_title">Application/Game aborted by fatal signal %d, check latestlog.txt for more details.</string>
     <string name="mcn_exit_confirm">Are you sure want to force close?</string>
     <string name="mcn_check_fail_vulkan_support">Zink (Vulkan) renderer is not supported on this device!</string>