aux/android: Looper trick for NativeActivity with app-glue

src/xrt/auxiliary/CMakeLists.txt

@@ -290,7 +290,7 @@ if(ANDROID)
 		android/android_globals.h
 		android/android_load_class.cpp
 		android/android_load_class.hpp
-		android/android_looper.c
+		android/android_looper.cpp
 		android/android_looper.h
 		android/org.freedesktop.monado.auxiliary.cpp
 		android/org.freedesktop.monado.auxiliary.hpp

src/xrt/auxiliary/android/android_looper.c

@@ -1,32 +0,0 @@
-// Copyright 2021, Qualcomm Innovation Center, Inc.
-// SPDX-License-Identifier: BSL-1.0
-/*!
- * @file
- * @brief Implementation of android looper functions.
- * @author Jarvis Huang
- * @ingroup aux_android
- */
-
-#include "android_looper.h"
-
-#include "util/u_logging.h"
-
-#include <android_native_app_glue.h>
-#include <android/looper.h>
-
-void
-android_looper_poll_until_activity_resumed()
-{
-	struct android_poll_source *source;
-	// Can we assume that activity already resumed if polling is failed?
-	while (ALooper_pollAll(-1, NULL, NULL, (void **)&source) == LOOPER_ID_MAIN) {
-		if (source) {
-			// Let callback owner handle the event
-			source->process(source->app, source);
-			if (source->app->activityState == APP_CMD_RESUME && source->app->window) {
-				U_LOG_I("Activity is in resume state and window is ready now");
-				break;
-			}
-		}
-	}
-}

src/xrt/auxiliary/android/android_looper.cpp

@@ -0,0 +1,51 @@
+// Copyright 2021, Qualcomm Innovation Center, Inc.
+// SPDX-License-Identifier: BSL-1.0
+/*!
+ * @file
+ * @brief Implementation of android looper functions.
+ * @author Jarvis Huang
+ * @ingroup aux_android
+ */
+
+#include "android_looper.h"
+
+#include "android/android_globals.h"
+#include "util/u_logging.h"
+#include "wrap/android.app.h"
+
+#include <android_native_app_glue.h>
+#include <android/looper.h>
+
+#include <android/log.h>
+
+void
+android_looper_poll_until_activity_resumed()
+{
+	jni::init(android_globals_get_vm());
+	wrap::android::app::Activity activity{(jobject)android_globals_get_activity()};
+	if (!jni::env()->IsInstanceOf(activity.object().getHandle(),
+	                              jni::Class("android/app/NativeActivity").getHandle())) {
+		// skip if given activity is not android.app.NativeActivity
+		U_LOG_I("Activity is not NativeActivity, skip");
+		return;
+	}
+
+	// Activity is in resumed state if window is active. Check Activity#onPostResume for detail.
+	if (!activity.getWindow().isNull() && activity.getWindow().call<bool>("isActive()Z")) {
+		// Already in resume state, skip
+		U_LOG_I("Activity is NativeActivity and already in resume state with window available, skip");
+		return;
+	}
+
+	struct android_poll_source *source;
+	while (ALooper_pollAll(1000, NULL, NULL, (void **)&source) >= 0) {
+		if (source) {
+			// Let callback owner handle the event
+			source->process(source->app, source);
+			if (source->app->activityState == APP_CMD_RESUME && source->app->window) {
+				U_LOG_I("Activity is in resume state with window available now");
+				break;
+			}
+		}
+	}
+}

src/xrt/auxiliary/android/android_looper.h

@@ -9,6 +9,8 @@
 
 #pragma once
 
+#include <xrt/xrt_config_os.h>
+
 #ifdef XRT_OS_ANDROID
 
 #ifdef __cplusplus

src/xrt/ipc/android/ipc_client_android.cpp

@@ -15,7 +15,6 @@
 #include "util/u_logging.h"
 
 #include "android/android_load_class.hpp"
-#include "android/android_looper.h"
 
 #include "wrap/android.app.h"
 
@@ -85,10 +84,6 @@ ipc_client_android_create(struct _JavaVM *vm, void *activity)
 int
 ipc_client_android_blocking_connect(struct ipc_client_android *ica)
 {
-	// To avoid deadlock on main thread, force client entering resume state
-	// before setting up IPC/surface
-	android_looper_poll_until_activity_resumed();
-
 	try {
 		int fd = ica->client.blockingConnect(ica->activity, XRT_ANDROID_PACKAGE);
 		return fd;

src/xrt/state_trackers/oxr/oxr_instance.c

@@ -20,6 +20,7 @@
 
 #ifdef XRT_OS_ANDROID
 #include "android/android_globals.h"
+#include "android/android_looper.h"
 #endif
 
 #include "oxr_objects.h"
@@ -263,6 +264,8 @@ oxr_instance_create(struct oxr_logger *log, const XrInstanceCreateInfo *createIn
 	    createInfo, XR_TYPE_INSTANCE_CREATE_INFO_ANDROID_KHR, XrInstanceCreateInfoAndroidKHR);
 	android_globals_store_vm_and_activity((struct _JavaVM *)create_info_android->applicationVM,
 	                                      create_info_android->applicationActivity);
+	// Trick to avoid deadlock on main thread. Only works for NativeActivity with app-glue.
+	android_looper_poll_until_activity_resumed();
 #endif
 
 	xinst_ret = xrt_instance_create(&i_info, &inst->xinst);