native-activity: port android_app_entry (mainloop init) from C to Rust

android-activity/native-activity-csrc/native-activity/native_app_glue/android_native_app_glue.c

@@ -61,7 +61,7 @@ int8_t android_app_read_cmd(struct android_app* android_app) {
     return -1;
 }
 
-static void print_cur_config(struct android_app* android_app) {
+void print_cur_config(struct android_app* android_app) {
     char lang[2], country[2];
     AConfiguration_getLanguage(android_app->config, lang);
     AConfiguration_getCountry(android_app->config, country);
@@ -180,7 +180,7 @@ void android_app_post_exec_cmd(struct android_app* android_app, int8_t cmd) {
     }
 }
 
-static void android_app_destroy(struct android_app* android_app) {
+void android_app_destroy(struct android_app* android_app) {
     LOGV("android_app_destroy!");
     free_saved_state(android_app);
     pthread_mutex_lock(&android_app->mutex);
@@ -194,37 +194,9 @@ static void android_app_destroy(struct android_app* android_app) {
     // Can't touch android_app object after this.
 }
 
-static void process_cmd(struct android_app* app, __attribute__((unused)) struct android_poll_source* source) {
+void process_cmd(struct android_app* app, __attribute__((unused)) struct android_poll_source* source) {
     int8_t cmd = android_app_read_cmd(app);
     android_app_pre_exec_cmd(app, cmd);
     if (app->onAppCmd != NULL) app->onAppCmd(app, cmd);
     android_app_post_exec_cmd(app, cmd);
 }
-
-void* android_app_entry(void* param) {
-    struct android_app* android_app = (struct android_app*)param;
-
-    android_app->config = AConfiguration_new();
-    AConfiguration_fromAssetManager(android_app->config, android_app->activity->assetManager);
-
-    print_cur_config(android_app);
-
-    android_app->cmdPollSource.id = LOOPER_ID_MAIN;
-    android_app->cmdPollSource.app = android_app;
-    android_app->cmdPollSource.process = process_cmd;
-
-    ALooper* looper = ALooper_prepare(ALOOPER_PREPARE_ALLOW_NON_CALLBACKS);
-    ALooper_addFd(looper, android_app->msgread, LOOPER_ID_MAIN, ALOOPER_EVENT_INPUT, NULL,
-            &android_app->cmdPollSource);
-    android_app->looper = looper;
-
-    pthread_mutex_lock(&android_app->mutex);
-    android_app->running = 1;
-    pthread_cond_broadcast(&android_app->cond);
-    pthread_mutex_unlock(&android_app->mutex);
-
-    _rust_glue_entry(android_app);
-
-    android_app_destroy(android_app);
-    return NULL;
-}

android-activity/native-activity-csrc/native-activity/native_app_glue/android_native_app_glue.h

@@ -334,13 +334,9 @@ void android_app_post_exec_cmd(struct android_app* android_app, int8_t cmd);
 void android_app_attach_input_queue_looper(struct android_app* android_app);
 void android_app_detach_input_queue_looper(struct android_app* android_app);
 
-void* android_app_entry(void* param);
-
-/**
- * This is the function that application code must implement, representing
- * the main entry to the app.
- */
-extern void _rust_glue_entry(struct android_app* app);
+void print_cur_config(struct android_app* android_app);
+void process_cmd(struct android_app* app, __attribute__((unused)) struct android_poll_source* source);
+void android_app_destroy(struct android_app* android_app);
 
 #ifdef __cplusplus
 }

android-activity/src/native_activity/ffi_aarch64.rs

@@ -6329,11 +6329,12 @@ extern "C" {
     pub fn android_app_detach_input_queue_looper(android_app: *mut android_app);
 }
 extern "C" {
-    pub fn android_app_entry(param: *mut ::std::os::raw::c_void) -> *mut ::std::os::raw::c_void;
+    pub fn print_cur_config(android_app: *mut android_app);
 }
 extern "C" {
-    #[doc = " This is the function that application code must implement, representing"]
-    #[doc = " the main entry to the app."]
-    pub fn _rust_glue_entry(app: *mut android_app);
+    pub fn process_cmd(app: *mut android_app, source: *mut android_poll_source);
+}
+extern "C" {
+    pub fn android_app_destroy(android_app: *mut android_app);
 }
 pub type __uint128_t = u128;

android-activity/src/native_activity/ffi_arm.rs

@@ -6809,10 +6809,11 @@ extern "C" {
     pub fn android_app_detach_input_queue_looper(android_app: *mut android_app);
 }
 extern "C" {
-    pub fn android_app_entry(param: *mut ::std::os::raw::c_void) -> *mut ::std::os::raw::c_void;
+    pub fn print_cur_config(android_app: *mut android_app);
 }
 extern "C" {
-    #[doc = " This is the function that application code must implement, representing"]
-    #[doc = " the main entry to the app."]
-    pub fn _rust_glue_entry(app: *mut android_app);
+    pub fn process_cmd(app: *mut android_app, source: *mut android_poll_source);
+}
+extern "C" {
+    pub fn android_app_destroy(android_app: *mut android_app);
 }

android-activity/src/native_activity/ffi_i686.rs

@@ -8554,11 +8554,12 @@ extern "C" {
     pub fn android_app_detach_input_queue_looper(android_app: *mut android_app);
 }
 extern "C" {
-    pub fn android_app_entry(param: *mut ::std::os::raw::c_void) -> *mut ::std::os::raw::c_void;
+    pub fn print_cur_config(android_app: *mut android_app);
 }
 extern "C" {
-    #[doc = " This is the function that application code must implement, representing"]
-    #[doc = " the main entry to the app."]
-    pub fn _rust_glue_entry(app: *mut android_app);
+    pub fn process_cmd(app: *mut android_app, source: *mut android_poll_source);
+}
+extern "C" {
+    pub fn android_app_destroy(android_app: *mut android_app);
 }
 pub type __builtin_va_list = *mut ::std::os::raw::c_char;

android-activity/src/native_activity/ffi_x86_64.rs

@@ -8572,12 +8572,13 @@ extern "C" {
     pub fn android_app_detach_input_queue_looper(android_app: *mut android_app);
 }
 extern "C" {
-    pub fn android_app_entry(param: *mut ::std::os::raw::c_void) -> *mut ::std::os::raw::c_void;
+    pub fn print_cur_config(android_app: *mut android_app);
 }
 extern "C" {
-    #[doc = " This is the function that application code must implement, representing"]
-    #[doc = " the main entry to the app."]
-    pub fn _rust_glue_entry(app: *mut android_app);
+    pub fn process_cmd(app: *mut android_app, source: *mut android_poll_source);
+}
+extern "C" {
+    pub fn android_app_destroy(android_app: *mut android_app);
 }
 pub type __builtin_va_list = [__va_list_tag; 1usize];
 #[repr(C)]

android-activity/src/native_activity/mod.rs

@@ -479,10 +479,49 @@ impl AndroidAppInner {
     }
 }
 
+
+////////////////////////////
+// Rust-side event loop
+////////////////////////////
+
+
 extern "C" fn android_app_main(arg: *mut libc::c_void) -> *mut libc::c_void {
-    unsafe { ffi::android_app_entry(arg) as *mut _ }
+    unsafe {
+        let android_app: *mut ffi::android_app = arg.cast();
+
+        (*android_app).config = ndk_sys::AConfiguration_new();
+        ndk_sys::AConfiguration_fromAssetManager((*android_app).config, (*(*android_app).activity).assetManager);
+
+        ffi::print_cur_config(android_app);
+
+        (*android_app).cmdPollSource.id = ffi::LOOPER_ID_MAIN as i32;
+        (*android_app).cmdPollSource.app = android_app;
+        (*android_app).cmdPollSource.process = Some(ffi::process_cmd);
+
+        let looper = ndk_sys::ALooper_prepare(ndk_sys::ALOOPER_PREPARE_ALLOW_NON_CALLBACKS as libc::c_int);
+        ndk_sys::ALooper_addFd(looper, (*android_app).msgread, ffi::LOOPER_ID_MAIN as libc::c_int, ndk_sys::ALOOPER_EVENT_INPUT as libc::c_int, None,
+                &mut (*android_app).cmdPollSource as *mut _ as *mut _);
+        (*android_app).looper = looper;
+
+        libc::pthread_mutex_lock(&mut (*android_app).mutex as *mut _);
+        (*android_app).running = 1;
+        libc::pthread_cond_broadcast(&mut (*android_app).cond as *mut _);
+        libc::pthread_mutex_unlock(&mut (*android_app).mutex as *mut _);
+
+        _rust_glue_entry(android_app);
+
+        ffi::android_app_destroy(android_app);
+
+        ptr::null_mut()
+    }
 }
 
+
+///////////////////////////////
+// Java-side callback handling
+///////////////////////////////
+
+
 unsafe fn android_app_create(activity: *mut ffi::ANativeActivity,
     saved_state_in: *const libc::c_void, saved_state_size: libc::size_t) -> *mut ffi::android_app
 {
@@ -575,10 +614,14 @@ unsafe fn android_app_write_cmd(android_app: *mut ffi::android_app, cmd: i8) {
             -1 => {
                 let err = std::io::Error::last_os_error();
                 if err.kind() != std::io::ErrorKind::Interrupted {
-                    panic!("Failure writing android_app cmd: {}", err);
+                    log::error!("Failure writing android_app cmd: {}", err);
+                    return;
                 }
             }
-            count => panic!("Spurious write of {count} bytes while writing android_app cmd")
+            count => {
+                log::error!("Spurious write of {count} bytes while writing android_app cmd");
+                return;
+            }
         }
     }
 }
@@ -762,8 +805,7 @@ extern "Rust" {
 // This is a spring board between android_native_app_glue and the user's
 // `app_main` function. This is run on a dedicated thread spawned
 // by android_native_app_glue.
-#[no_mangle]
-pub unsafe extern "C" fn _rust_glue_entry(app: *mut ffi::android_app) {
+pub unsafe fn _rust_glue_entry(app: *mut ffi::android_app) {
     // Maybe make this stdout/stderr redirection an optional / opt-in feature?...
     let mut logpipe: [RawFd; 2] = Default::default();
     libc::pipe(logpipe.as_mut_ptr());