RetroArch/android/native/jni/main.c

/*  RetroArch - A frontend for libretro.
 *  Copyright (C) 2010-2012 - Hans-Kristian Arntzen
 *  Copyright (C) 2011-2012 - Daniel De Matteis
 * 
 *  RetroArch is free software: you can redistribute it and/or modify it under the terms
 *  of the GNU General Public License as published by the Free Software Found-
 *  ation, either version 3 of the License, or (at your option) any later version.
 *
 *  RetroArch is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 *  PURPOSE.  See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with RetroArch.
 *  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <sys/resource.h>

#include "android_general.h"
#include "jni_wrapper.h"
#include "../../../general.h"
#include "../../../performance.h"
#include "../../../driver.h"

#include "../../../config.def.h"

void free_saved_state(struct android_app* android_app)
{
   pthread_mutex_lock(&android_app->mutex);

   if (android_app->savedState != NULL)
   {
      free(android_app->savedState);
      android_app->savedState = NULL;
      android_app->savedStateSize = 0;
   }

   pthread_mutex_unlock(&android_app->mutex);
}

static 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);

   RARCH_LOG("Config: mcc=%d mnc=%d lang=%c%c cnt=%c%c orien=%d touch=%d dens=%d "
         "keys=%d nav=%d keysHid=%d navHid=%d sdk=%d size=%d long=%d "
         "modetype=%d modenight=%d\n",
         AConfiguration_getMcc(android_app->config),
         AConfiguration_getMnc(android_app->config),
         lang[0], lang[1], country[0], country[1],
         AConfiguration_getOrientation(android_app->config),
         AConfiguration_getTouchscreen(android_app->config),
         AConfiguration_getDensity(android_app->config),
         AConfiguration_getKeyboard(android_app->config),
         AConfiguration_getNavigation(android_app->config),
         AConfiguration_getKeysHidden(android_app->config),
         AConfiguration_getNavHidden(android_app->config),
         AConfiguration_getSdkVersion(android_app->config),
         AConfiguration_getScreenSize(android_app->config),
         AConfiguration_getScreenLong(android_app->config),
         AConfiguration_getUiModeType(android_app->config),
         AConfiguration_getUiModeNight(android_app->config));
}

/**
 * Process the next main command.
 */
void engine_handle_cmd(struct android_app* android_app, int32_t cmd)
{
   switch (cmd)
   {
      case APP_CMD_INPUT_CHANGED:
         RARCH_LOG("APP_CMD_INPUT_CHANGED\n");
         
         /* PRE-EXEC */
         pthread_mutex_lock(&android_app->mutex);
         if (android_app->inputQueue != NULL)
            AInputQueue_detachLooper(android_app->inputQueue);
         android_app->inputQueue = android_app->pendingInputQueue;
         if (android_app->inputQueue != NULL)
         {
            RARCH_LOG("Attaching input queue to looper");
            AInputQueue_attachLooper(android_app->inputQueue,
                  android_app->looper, LOOPER_ID_INPUT, NULL,
                  NULL);
         }
         pthread_cond_broadcast(&android_app->cond);
         pthread_mutex_unlock(&android_app->mutex);
         
         break;
      case APP_CMD_SAVE_STATE:
         RARCH_LOG("engine_handle_cmd: APP_CMD_SAVE_STATE.\n");

         /* EXEC */
         /* The system has asked us to save our current state.  Do so. */
         android_app->savedState = malloc(sizeof(struct saved_state));
         *((struct saved_state*)android_app->savedState) = g_android.state;
         android_app->savedStateSize = sizeof(struct saved_state);

         /* POSTEXEC */
         pthread_mutex_lock(&android_app->mutex);
         android_app->stateSaved = 1;
         pthread_cond_broadcast(&android_app->cond);
         pthread_mutex_unlock(&android_app->mutex);

         break;
      case APP_CMD_INIT_WINDOW:
         RARCH_LOG("engine_handle_cmd: APP_CMD_INIT_WINDOW.\n");

         pthread_mutex_lock(&android_app->mutex);

         /* PREEXEC */

         /* EXEC */
         /* The window is being shown, get it ready. */
         android_app->window = android_app->pendingWindow;


         pthread_cond_broadcast(&android_app->cond);
         pthread_mutex_unlock(&android_app->mutex);


         break;
      case APP_CMD_RESUME:
         RARCH_LOG("engine_handle_cmd: APP_CMD_RESUME.\n");

         /* PREEXEC */
         pthread_mutex_lock(&android_app->mutex);
         android_app->activityState = cmd;
         pthread_cond_broadcast(&android_app->cond);
         pthread_mutex_unlock(&android_app->mutex);

         /* POSTEXEC */
         free_saved_state(android_app);
         
         g_extern.lifecycle_state &= ~(1ULL << RARCH_PAUSE_TOGGLE);
         break;
      case APP_CMD_START:
         RARCH_LOG("engine_handle_cmd: APP_CMD_START.\n");

         /* PREEXEC */
         pthread_mutex_lock(&android_app->mutex);
         android_app->activityState = cmd;
         pthread_cond_broadcast(&android_app->cond);
         pthread_mutex_unlock(&android_app->mutex);
         break;
      case APP_CMD_PAUSE:
         RARCH_LOG("engine_handle_cmd: APP_CMD_PAUSE.\n");

         /* PREEXEC */
         pthread_mutex_lock(&android_app->mutex);
         android_app->activityState = cmd;
         pthread_cond_broadcast(&android_app->cond);
         pthread_mutex_unlock(&android_app->mutex);

         /* EXEC */
         if(g_extern.lifecycle_state & (1ULL << RARCH_QUIT_KEY)) { }
         else
         {
            /* Setting reentrancy */
            RARCH_LOG("Setting up RetroArch re-entrancy...\n");
            g_extern.lifecycle_state |= (1ULL << RARCH_REENTRANT);
            g_extern.lifecycle_state |= (1ULL << RARCH_PAUSE_TOGGLE);
         }
         break;
      case APP_CMD_STOP:
         RARCH_LOG("engine_handle_cmd: APP_CMD_STOP.\n");

         /* PREEXEC */
         pthread_mutex_lock(&android_app->mutex);
         android_app->activityState = cmd;
         pthread_cond_broadcast(&android_app->cond);
         pthread_mutex_unlock(&android_app->mutex);
         break;
      case APP_CMD_CONFIG_CHANGED:
         RARCH_LOG("engine_handle_cmd: APP_CMD_CONFIG_CHANGED.\n");

         /* PREEXEC */
         AConfiguration_fromAssetManager(android_app->config,
               android_app->activity->assetManager);
         print_cur_config(android_app);
         break;
      case APP_CMD_TERM_WINDOW:
         RARCH_LOG("engine_handle_cmd: APP_CMD_TERM_WINDOW.\n");

         pthread_mutex_lock(&android_app->mutex);
         /* PREEXEC */

         /* EXEC */
         /* The window is being hidden or closed, clean it up. */
         /* terminate display/EGL context here */
         if(g_extern.lifecycle_state & (1ULL << RARCH_REENTRANT))
         {
            uninit_drivers();
            g_android.window_ready = false;
         }

         /* POSTEXEC */
         android_app->window = NULL;
         pthread_cond_broadcast(&android_app->cond);
         pthread_mutex_unlock(&android_app->mutex);
         break;
      case APP_CMD_GAINED_FOCUS:
         RARCH_LOG("engine_handle_cmd: APP_CMD_GAINED_FOCUS.\n");

         /* EXEC */
         break;
      case APP_CMD_LOST_FOCUS:
         RARCH_LOG("engine_handle_cmd: APP_CMD_LOST_FOCUS.\n");

         /* EXEC */
         break;
      case APP_CMD_DESTROY:
         RARCH_LOG("engine_handle_cmd: APP_CMD_DESTROY\n");

         /* PREEXEC */
         g_extern.lifecycle_state |= (1ULL << RARCH_QUIT_KEY);
         break;
   }
}

#define MAX_ARGS 32

bool android_run_events(struct android_app* android_app)
{
   // Read all pending events.
   int id;

   RARCH_LOG("RetroArch Android paused.\n");

   // Block forever waiting for events.
   while ((id = ALooper_pollOnce(input_key_pressed_func(RARCH_PAUSE_TOGGLE) ? -1 : 100, NULL, 0, NULL)) >= 0)
   {
      // Process this event.
      if (id)
      {
         int8_t cmd;

         if (read(android_app->msgread, &cmd, sizeof(cmd)) == sizeof(cmd))
         {
            if(cmd == APP_CMD_SAVE_STATE)
               free_saved_state(android_app);
         }
         else
            cmd = -1;

         engine_handle_cmd(android_app, cmd);

         if (cmd == APP_CMD_INIT_WINDOW)
         {
            if(g_extern.lifecycle_state & (1ULL << RARCH_REENTRANT))
                  init_drivers();

            if (android_app->window != NULL)
               g_android.window_ready = true;
         }
      }

      // Check if we are exiting.
      if (g_extern.lifecycle_state & (1ULL << RARCH_QUIT_KEY))
         return false;
   }

   RARCH_LOG("RetroArch Android unpaused.\n");
   
   return true;
}

/**
 * This is the main entry point of a native application that is using
 * android_native_app_glue.  It runs in its own thread, with its own
 * event loop for receiving input events and doing other things.
 */
static void jni_get(struct jni_params *in_params, struct jni_out_params_char *out_args)
{
   char obj_method_name[128];
   char obj_method_signature[128];
   jclass class_ptr = NULL;
   jobject obj = NULL;
   jmethodID giid = NULL;
   jstring ret_char;

   snprintf(obj_method_name, sizeof(obj_method_name), "getStringExtra");
   snprintf(obj_method_signature, sizeof(obj_method_signature), "(Ljava/lang/String;)Ljava/lang/String;");

   GET_OBJECT_CLASS(in_params->env, class_ptr, in_params->class_obj);
   GET_METHOD_ID(in_params->env, giid, class_ptr, in_params->method_name, in_params->method_signature);
   CALL_OBJ_METHOD(in_params->env, obj, in_params->class_obj, giid);

   GET_OBJECT_CLASS(in_params->env, class_ptr, obj);
   GET_METHOD_ID(in_params->env, giid, class_ptr, obj_method_name, obj_method_signature);

   CALL_OBJ_METHOD_PARAM(in_params->env, ret_char, obj, giid, (*in_params->env)->NewStringUTF(in_params->env, out_args->in));

   if(giid != NULL && ret_char)
   {
      const char *test_argv = (*in_params->env)->GetStringUTFChars(in_params->env, ret_char, 0);
      strncpy(out_args->out, test_argv, out_args->out_sizeof);
      (*in_params->env)->ReleaseStringUTFChars(in_params->env, ret_char, test_argv);
   }
}

static float refreshrate;

static int android_app_set_argv(char** argv)
{
   char rom_path[512];
   char libretro_path[512];

   struct jni_params in_params;
   struct jni_out_params_char out_args;

   JNI_OnLoad(g_android.app->activity->vm, NULL);

   // Get arguments */

   in_params.java_vm = g_android.app->activity->vm;
   in_params.class_obj = g_android.app->activity->clazz;

   snprintf(in_params.method_name, sizeof(in_params.method_name), "getIntent");
   snprintf(in_params.method_signature, sizeof(in_params.method_signature), "()Landroid/content/Intent;");

   out_args.out = rom_path;
   out_args.out_sizeof = sizeof(rom_path);
   snprintf(out_args.in, sizeof(out_args.in), "ROM");

   (*in_params.java_vm)->AttachCurrentThread(in_params.java_vm, &in_params.env, 0);

   /* for ROM - begin */
   jni_get(&in_params, &out_args);

   /* for ROM - end */

   out_args.out = libretro_path;
   out_args.out_sizeof = sizeof(libretro_path);
   snprintf(out_args.in, sizeof(out_args.in), "LIBRETRO");

   /* for LIBRETRO - begin */
   jni_get(&in_params, &out_args);
   /* for LIBRETRO - end */

   char refreshrate_char[128];
   
   out_args.out = refreshrate_char;
   out_args.out_sizeof = sizeof(refreshrate_char);
   snprintf(out_args.in, sizeof(out_args.in), "REFRESHRATE");

   /* for REFRESHRATE - begin */
   jni_get(&in_params, &out_args);
   /* for REFRESHRATE - end */

   (*in_params.java_vm)->DetachCurrentThread(in_params.java_vm);

   refreshrate = (float)strtod(refreshrate_char, NULL);

   RARCH_LOG("Checking arguments passed...\n");
   RARCH_LOG("ROM Filename: [%s].\n", rom_path);
   RARCH_LOG("Libretro path: [%s].\n", libretro_path);
   RARCH_LOG("Display Refresh rate: %.2fHz.\n", refreshrate);

   int argc = 0;

   argv[argc++] = strdup("retroarch");
   argv[argc++] = strdup(rom_path);
   argv[argc++] = strdup("-L");
   argv[argc++] = strdup(libretro_path);
   argv[argc++] = strdup("-v");

   return argc;
}

static 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);

   ALooper* looper = ALooper_prepare(ALOOPER_PREPARE_ALLOW_NON_CALLBACKS);
   ALooper_addFd(looper, android_app->msgread, LOOPER_ID_MAIN, ALOOPER_EVENT_INPUT, NULL, NULL);
   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);

   memset(&g_android, 0, sizeof(g_android));
   g_android.app = android_app;

   char *argv[MAX_ARGS] = {NULL};
   int argc = android_app_set_argv(argv);

   if (android_app->savedState != NULL)
   {
      // We are starting with a previous saved state; restore from it.
      RARCH_LOG("Restoring reentrant savestate.\n");
      g_android.state = *(struct saved_state*)android_app->savedState;
      g_extern.lifecycle_state = g_android.state.lifecycle_state;
   }

   bool rarch_reentrant = (g_extern.lifecycle_state & (1ULL << RARCH_REENTRANT));

   if(rarch_reentrant)
   {
      RARCH_LOG("Native Activity started (reentrant).\n");
   }
   else
   {
      RARCH_LOG("Native Activity started.\n");
      rarch_main_clear_state();
   }


   g_extern.verbose = true;

   bool disp_refresh_read = refreshrate > 0.0f;

   g_android.disp_refresh_rate = refresh_rate;

   if(disp_refresh_read)
   {
      if(refreshrate < refresh_rate)
      {
         RARCH_WARN("Display refresh rate of your device is likely lower than 60Hz.\n");
         g_android.disp_refresh_rate = refreshrate;
      }
   }

   RARCH_LOG("Setting RetroArch video refresh rate to: %.2fHz.\n", g_android.disp_refresh_rate);

   while(!g_android.window_ready)
   {
      if(!android_run_events(android_app))
         goto exit;
   }

   int init_ret;

   if (rarch_reentrant)
   {
      init_ret = 0;

      /* We've done everything state-wise needed for RARCH_REENTRANT,
       * get rid of it now */
      g_extern.lifecycle_state &= ~(1ULL << RARCH_REENTRANT);
   }
   else if ((init_ret = rarch_main_init(argc, argv)) != 0)
   {
      RARCH_LOG("Initialization failed.\n");
      g_extern.lifecycle_state |= (1ULL << RARCH_QUIT_KEY);
   }
   else
      RARCH_LOG("Initializing succeeded.\n");

   if (init_ret == 0)
   {
      RARCH_LOG("RetroArch started.\n");
      rarch_init_msg_queue();
      g_android.last_orient = AConfiguration_getOrientation(android_app->config);
      while((input_key_pressed_func(RARCH_PAUSE_TOGGLE)) ? android_run_events(g_android.app) : rarch_main_iterate());
      RARCH_LOG("RetroArch stopped.\n");
   }

exit:
   if(g_extern.lifecycle_state & (1ULL << RARCH_QUIT_KEY))
   {
      RARCH_LOG("Deinitializing RetroArch...\n");
      rarch_main_deinit();
      rarch_deinit_msg_queue();
#ifdef PERF_TEST
      rarch_perf_log();
#endif
      rarch_main_clear_state();

      /* Quit RetroArch */
      RARCH_LOG("android_app_destroy!");
      free_saved_state(android_app);
      pthread_mutex_lock(&android_app->mutex);

      if (android_app->inputQueue != NULL)
         AInputQueue_detachLooper(android_app->inputQueue);

      AConfiguration_delete(android_app->config);
      android_app->destroyed = 1;
      pthread_cond_broadcast(&android_app->cond);
      pthread_mutex_unlock(&android_app->mutex);
      // Can't touch android_app object after this.
      exit(0);
   }

   return NULL;
}


static inline void android_app_write_cmd(struct android_app* android_app, int8_t cmd)
{
   if (write(android_app->msgwrite, &cmd, sizeof(cmd)) != sizeof(cmd))
      RARCH_ERR("Failure writing android_app cmd: %s\n", strerror(errno));
}

static void android_app_set_input(struct android_app* android_app, AInputQueue* inputQueue)
{
   pthread_mutex_lock(&android_app->mutex);
   android_app->pendingInputQueue = inputQueue;
   android_app_write_cmd(android_app, APP_CMD_INPUT_CHANGED);
   while (android_app->inputQueue != android_app->pendingInputQueue)
      pthread_cond_wait(&android_app->cond, &android_app->mutex);
   pthread_mutex_unlock(&android_app->mutex);
}

static void android_app_set_window(struct android_app* android_app, ANativeWindow* window)
{
   pthread_mutex_lock(&android_app->mutex);
   if (android_app->pendingWindow != NULL)
      android_app_write_cmd(android_app, APP_CMD_TERM_WINDOW);

   android_app->pendingWindow = window;

   if (window != NULL)
      android_app_write_cmd(android_app, APP_CMD_INIT_WINDOW);

   while (android_app->window != android_app->pendingWindow)
      pthread_cond_wait(&android_app->cond, &android_app->mutex);

   pthread_mutex_unlock(&android_app->mutex);
}

static void android_app_set_activity_state(struct android_app* android_app, int8_t cmd)
{
   pthread_mutex_lock(&android_app->mutex);
   android_app_write_cmd(android_app, cmd);
   while (android_app->activityState != cmd)
      pthread_cond_wait(&android_app->cond, &android_app->mutex);
   pthread_mutex_unlock(&android_app->mutex);
}

static void onDestroy(ANativeActivity* activity)
{
   RARCH_LOG("Destroy: %p\n", activity);
   struct android_app* android_app = (struct android_app*)activity->instance;

   pthread_mutex_lock(&android_app->mutex);
   android_app_write_cmd(android_app, APP_CMD_DESTROY);
   while (!android_app->destroyed)
      pthread_cond_wait(&android_app->cond, &android_app->mutex);
   pthread_mutex_unlock(&android_app->mutex);

   close(android_app->msgread);
   close(android_app->msgwrite);
   pthread_cond_destroy(&android_app->cond);
   pthread_mutex_destroy(&android_app->mutex);
   free(android_app);
}

static void onStart(ANativeActivity* activity)
{
   RARCH_LOG("Start: %p\n", activity);
   android_app_set_activity_state((struct android_app*)activity->instance, APP_CMD_START);
}

static void onResume(ANativeActivity* activity)
{
   RARCH_LOG("Resume: %p\n", activity);
   android_app_set_activity_state((struct android_app*)activity->instance, APP_CMD_RESUME);
}

static void* onSaveInstanceState(ANativeActivity* activity, size_t* outLen)
{
   struct android_app* android_app = (struct android_app*)activity->instance;
   void* savedState = NULL;

   RARCH_LOG("SaveInstanceState: %p\n", activity);
   pthread_mutex_lock(&android_app->mutex);
   android_app->stateSaved = 0;
   android_app_write_cmd(android_app, APP_CMD_SAVE_STATE);
   while (!android_app->stateSaved)
      pthread_cond_wait(&android_app->cond, &android_app->mutex);

   if (android_app->savedState != NULL)
   {
      savedState = android_app->savedState;
      *outLen = android_app->savedStateSize;
      android_app->savedState = NULL;
      android_app->savedStateSize = 0;
   }

   pthread_mutex_unlock(&android_app->mutex);

   return savedState;
}

static void onPause(ANativeActivity* activity)
{
   RARCH_LOG("Pause: %p\n", activity);
   android_app_set_activity_state((struct android_app*)activity->instance, APP_CMD_PAUSE);
}

static void onStop(ANativeActivity* activity)
{
   RARCH_LOG("Stop: %p\n", activity);
   android_app_set_activity_state((struct android_app*)activity->instance, APP_CMD_STOP);
}

static void onConfigurationChanged(ANativeActivity* activity)
{
   struct android_app* android_app = (struct android_app*)activity->instance;
   RARCH_LOG("ConfigurationChanged: %p\n", activity);
   android_app_write_cmd(android_app, APP_CMD_CONFIG_CHANGED);
}

static void onWindowFocusChanged(ANativeActivity* activity, int focused)
{
   RARCH_LOG("WindowFocusChanged: %p -- %d\n", activity, focused);
   android_app_write_cmd((struct android_app*)activity->instance,
         focused ? APP_CMD_GAINED_FOCUS : APP_CMD_LOST_FOCUS);
}

static void onNativeWindowCreated(ANativeActivity* activity, ANativeWindow* window)
{
   RARCH_LOG("NativeWindowCreated: %p -- %p\n", activity, window);
   android_app_set_window((struct android_app*)activity->instance, window);
}

static void onNativeWindowDestroyed(ANativeActivity* activity, ANativeWindow* window)
{
   RARCH_LOG("NativeWindowDestroyed: %p -- %p\n", activity, window);


   android_app_set_window((struct android_app*)activity->instance, NULL);
}

static void onInputQueueCreated(ANativeActivity* activity, AInputQueue* queue)
{
   RARCH_LOG("InputQueueCreated: %p -- %p\n", activity, queue);
   android_app_set_input((struct android_app*)activity->instance, queue);
}

static void onInputQueueDestroyed(ANativeActivity* activity, AInputQueue* queue)
{
   RARCH_LOG("InputQueueDestroyed: %p -- %p\n", activity, queue);
   android_app_set_input((struct android_app*)activity->instance, NULL);
}

// --------------------------------------------------------------------
// Native activity interaction (called from main thread)
// --------------------------------------------------------------------

void ANativeActivity_onCreate(ANativeActivity* activity,
      void* savedState, size_t savedStateSize)
{
   RARCH_LOG("Creating Native Activity: %p\n", activity);
   activity->callbacks->onDestroy = onDestroy;
   activity->callbacks->onStart = onStart;
   activity->callbacks->onResume = onResume;
   activity->callbacks->onSaveInstanceState = onSaveInstanceState;
   activity->callbacks->onPause = onPause;
   activity->callbacks->onStop = onStop;
   activity->callbacks->onConfigurationChanged = onConfigurationChanged;
   activity->callbacks->onLowMemory = NULL;
   activity->callbacks->onWindowFocusChanged = onWindowFocusChanged;
   activity->callbacks->onNativeWindowCreated = onNativeWindowCreated;
   activity->callbacks->onNativeWindowDestroyed = onNativeWindowDestroyed;
   activity->callbacks->onInputQueueCreated = onInputQueueCreated;
   activity->callbacks->onInputQueueDestroyed = onInputQueueDestroyed;

   // these are set only for the native activity, and are reset when it ends
   ANativeActivity_setWindowFlags(activity, AWINDOW_FLAG_KEEP_SCREEN_ON | AWINDOW_FLAG_FULLSCREEN, 0);

   struct android_app* android_app = (struct android_app*)malloc(sizeof(struct android_app));
   memset(android_app, 0, sizeof(struct android_app));
   android_app->activity = activity;

   pthread_mutex_init(&android_app->mutex, NULL);
   pthread_cond_init(&android_app->cond, NULL);

   if (savedState != NULL)
   {
      android_app->savedState = malloc(savedStateSize);
      android_app->savedStateSize = savedStateSize;
      memcpy(android_app->savedState, savedState, savedStateSize);
   }

   int msgpipe[2];
   if (pipe(msgpipe))
   {
      RARCH_ERR("could not create pipe: %s.\n", strerror(errno));
      activity->instance = NULL;
   }
   else
   {
      android_app->msgread = msgpipe[0];
      android_app->msgwrite = msgpipe[1];

      pthread_attr_t attr; 
      pthread_attr_init(&attr);
      pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
      pthread_create(&android_app->thread, &attr, android_app_entry, android_app);

      // Wait for thread to start.
      pthread_mutex_lock(&android_app->mutex);
      while (!android_app->running)
         pthread_cond_wait(&android_app->cond, &android_app->mutex);
      pthread_mutex_unlock(&android_app->mutex);

      activity->instance = android_app;
   }
}