Remove prebuilt static library "libthreaded_app.a".

Make the "glue library" part of the NDK as an importable module,
this has several benefits:

- no need to distribute a binary here with no easy way to regenerate it

- no need to explicitely list -lthreaded_app in your LOCAL_LDLIBS
  (this is handled automatically by the module import capability)

- allows easier native debugging of what's really happening.

Note that the header is renamed <threaded_native_app.h>

+ Modify the native-activity sample to use and import the new module
+ Start documenting usage in the header file. We probably need something
  better, and will probably put it under development/ndk/docs/ at some
  point.

After this patch, we should be able to get rid of the code under
framework/base/native/{include.glue}

Change-Id: I6e81d70a225a6ca006beabf6e8b42529e8f371b9

ndk/samples/native-activity/jni/Android.mk

@@ -18,6 +18,9 @@ include $(CLEAR_VARS)
 
 LOCAL_MODULE    := native-activity
 LOCAL_SRC_FILES := main.c glutils.c
-LOCAL_LDLIBS    := -lthreaded_app -llog -landroid -lEGL -lGLESv1_CM
+LOCAL_LDLIBS    := -llog -landroid -lEGL -lGLESv1_CM
+LOCAL_STATIC_LIBRARIES := android_native_app_glue
 
 include $(BUILD_SHARED_LIBRARY)
+
+$(call import-module,android/native_app_glue)

ndk/samples/native-activity/jni/main.c

@@ -19,13 +19,13 @@
 
 #include <errno.h>
 
-#include <android_glue/threaded_app.h>
+#include <android_native_app_glue.h>
 
 #include "glutils.h"
 
 struct engine {
     struct android_app* app;
-    
+
     int animating;
     EGLDisplay display;
     EGLSurface surface;
@@ -69,13 +69,13 @@ static int engine_init_display(struct engine* engine) {
     engine->width = w;
     engine->height = h;
     engine->angle = 0;
-    
+
     // Initialize GL state.
     glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_FASTEST);
     glEnable(GL_CULL_FACE);
     glShadeModel(GL_SMOOTH);
     glEnable(GL_DEPTH_TEST);
-    
+
     return 0;
 }
 
@@ -84,7 +84,7 @@ static void engine_draw_frame(struct engine* engine) {
         // No display.
         return;
     }
-    
+
     glClearColor(((float)engine->x)/engine->width, engine->angle,
             ((float)engine->y)/engine->height, 1);
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
@@ -108,7 +108,7 @@ static void engine_draw_frame(struct engine* engine) {
 #endif
 
     eglSwapBuffers(engine->display, engine->surface);
-    
+
     //engine->angle += 1.2f;
 }
 
@@ -144,7 +144,7 @@ static int engine_do_ui_event(struct engine* engine) {
     } else {
         LOGI("Failure reading next input event: %s\n", strerror(errno));
     }
-    
+
     return 1;
 }
 
@@ -169,19 +169,19 @@ static int32_t engine_do_main_cmd(struct engine* engine) {
             res = android_app_exec_cmd(engine->app, cmd);
             break;
     }
-    
+
     return res;
 }
 
 void android_main(struct android_app* state) {
     struct engine engine;
-    
+
     memset(&engine, 0, sizeof(engine));
     state->userData = &engine;
     engine.app = state;
-    
+
     // loop waiting for stuff to do.
-    
+
     while (1) {
         // Read all pending events.
         int fd;
@@ -201,7 +201,7 @@ void android_main(struct android_app* state) {
                     break;
             }
         }
-        
+
         if (engine.animating) {
             // Done with events; draw next animation frame.
             engine.angle += .01f;

ndk/samples/native-plasma/jni/Android.mk

@@ -18,6 +18,9 @@ include $(CLEAR_VARS)
 
 LOCAL_MODULE    := native-plasma
 LOCAL_SRC_FILES := plasma.c
-LOCAL_LDLIBS    := -lthreaded_app -lm -llog -landroid
+LOCAL_LDLIBS    := -lm -llog -landroid
+LOCAL_STATIC_LIBRARIES := android_native_app_glue
 
 include $(BUILD_SHARED_LIBRARY)
+
+$(call import-module,android/native_app_glue)

ndk/samples/native-plasma/jni/plasma.c

@@ -15,7 +15,7 @@
  *
  */
 
-#include <android_glue/threaded_app.h>
+#include <android_native_app_glue.h>
 
 #include <errno.h>
 #include <jni.h>
@@ -374,9 +374,9 @@ stats_endFrame( Stats*  s )
 
 struct engine {
     struct android_app* app;
-    
+
     Stats stats;
-    
+
     int animating;
 };
 
@@ -385,20 +385,20 @@ static void engine_draw_frame(struct engine* engine) {
         // No window.
         return;
     }
-    
+
     ANativeWindow_Buffer buffer;
     if (ANativeWindow_lock(engine->app->window, &buffer, NULL) < 0) {
         LOGW("Unable to lock window buffer");
         return;
     }
-    
+
     stats_startFrame(&engine->stats);
 
     struct timespec t;
     t.tv_sec = t.tv_nsec = 0;
     clock_gettime(CLOCK_MONOTONIC, &t);
     int64_t time_ms = (((int64_t)t.tv_sec)*1000000000LL + t.tv_nsec)/1000000;
-    
+
     /* Now fill the values with a nice little plasma */
     fill_plasma(&buffer, time_ms);
 
@@ -429,7 +429,7 @@ static int engine_do_ui_event(struct engine* engine) {
     } else {
         LOGI("Failure reading next input event: %s\n", strerror(errno));
     }
-    
+
     return 1;
 }
 
@@ -453,7 +453,7 @@ static int32_t engine_do_main_cmd(struct engine* engine) {
             res = android_app_exec_cmd(engine->app, cmd);
             break;
     }
-    
+
     return res;
 }
 
@@ -461,20 +461,20 @@ void android_main(struct android_app* state) {
     static int init;
 
     struct engine engine;
-    
+
     memset(&engine, 0, sizeof(engine));
     state->userData = &engine;
     engine.app = state;
-    
+
     if (!init) {
         init_tables();
         init = 1;
     }
-    
+
     stats_init(&engine.stats);
-        
+
     // loop waiting for stuff to do.
-    
+
     while (1) {
         // Read all pending events.
         int fd;
@@ -494,7 +494,7 @@ void android_main(struct android_app* state) {
                     break;
             }
         }
-        
+
         if (engine.animating) {
             engine_draw_frame(&engine);
         }

ndk/sources/android/native_app_glue/Android.mk

@@ -0,0 +1,10 @@
+LOCAL_PATH:= $(call my-dir)
+
+include $(CLEAR_VARS)
+
+LOCAL_MODULE:= android_native_app_glue
+LOCAL_SRC_FILES:= android_native_app_glue.c
+LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)
+LOCAL_EXPORT_LDLIBS := -llog
+
+include $(BUILD_STATIC_LIBRARY)

ndk/sources/android/native_app_glue/android_native_app_glue.c

@@ -0,0 +1,278 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <jni.h>
+
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/resource.h>
+
+#include "android_native_app_glue.h"
+#include <android/log.h>
+
+#define LOGI(...) ((void)__android_log_print(ANDROID_LOG_INFO, "threaded_app", __VA_ARGS__))
+#define LOGW(...) ((void)__android_log_print(ANDROID_LOG_WARN, "threaded_app", __VA_ARGS__))
+
+int8_t android_app_read_cmd(struct android_app* android_app) {
+    int8_t cmd;
+    if (read(android_app->msgread, &cmd, sizeof(cmd)) == sizeof(cmd)) {
+        return cmd;
+    } else {
+        LOGW("No data on command pipe!");
+    }
+    return -1;
+}
+
+int32_t android_app_exec_cmd(struct android_app* android_app, int8_t cmd) {
+    switch (cmd) {
+        case APP_CMD_INPUT_CHANGED:
+            LOGI("APP_CMD_INPUT_CHANGED\n");
+            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) {
+                LOGI("Attaching input queue to looper");
+                AInputQueue_attachLooper(android_app->inputQueue,
+                        android_app->looper, NULL, (void*)LOOPER_ID_EVENT);
+            }
+            pthread_cond_broadcast(&android_app->cond);
+            pthread_mutex_unlock(&android_app->mutex);
+            break;
+
+        case APP_CMD_WINDOW_CHANGED:
+            LOGI("APP_CMD_WINDOW_CHANGED\n");
+            pthread_mutex_lock(&android_app->mutex);
+            android_app->window = android_app->pendingWindow;
+            pthread_cond_broadcast(&android_app->cond);
+            pthread_mutex_unlock(&android_app->mutex);
+            break;
+
+        case APP_CMD_START:
+        case APP_CMD_RESUME:
+        case APP_CMD_PAUSE:
+        case APP_CMD_STOP:
+            LOGI("activityState=%d\n", cmd);
+            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_DESTROY:
+            LOGI("APP_CMD_DESTROY\n");
+            android_app->destroyRequested = 1;
+            break;
+    }
+
+    return android_app->destroyRequested ? 0 : 1;
+}
+
+static void android_app_destroy(struct android_app* android_app) {
+    LOGI("android_app_destroy!");
+    pthread_mutex_lock(&android_app->mutex);
+    if (android_app->inputQueue != NULL) {
+        AInputQueue_detachLooper(android_app->inputQueue);
+    }
+    android_app->destroyed = 1;
+    pthread_cond_broadcast(&android_app->cond);
+    pthread_mutex_unlock(&android_app->mutex);
+    // Can't touch android_app object after this.
+}
+
+static void* android_app_entry(void* param) {
+    struct android_app* android_app = (struct android_app*)param;
+
+    ALooper* looper = ALooper_prepare(ALOOPER_PREPARE_ALLOW_NON_CALLBACKS);
+    ALooper_addFd(looper, android_app->msgread, POLLIN, NULL, (void*)LOOPER_ID_MAIN);
+    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);
+
+    android_main(android_app);
+
+    android_app_destroy(android_app);
+    return NULL;
+}
+
+// --------------------------------------------------------------------
+// Native activity interaction (called from main thread)
+// --------------------------------------------------------------------
+
+static struct android_app* android_app_create(ANativeActivity* activity) {
+    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);
+
+    int msgpipe[2];
+    if (pipe(msgpipe)) {
+        LOGI("could not create pipe: %s", strerror(errno));
+    }
+    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);
+
+    return android_app;
+}
+
+static void android_app_write_cmd(struct android_app* android_app, int8_t cmd) {
+    if (write(android_app->msgwrite, &cmd, sizeof(cmd)) != sizeof(cmd)) {
+        LOGI("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);
+    android_app->pendingWindow = window;
+    android_app_write_cmd(android_app, APP_CMD_WINDOW_CHANGED);
+    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 android_app_free(struct android_app* android_app) {
+    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 onDestroy(ANativeActivity* activity) {
+    LOGI("Destroy: %p\n", activity);
+    android_app_free((struct android_app*)activity->instance);
+}
+
+static void onStart(ANativeActivity* activity) {
+    LOGI("Start: %p\n", activity);
+    android_app_set_activity_state((struct android_app*)activity->instance, APP_CMD_START);
+}
+
+static void onResume(ANativeActivity* activity) {
+    LOGI("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) {
+    LOGI("SaveInstanceState: %p\n", activity);
+    return NULL;
+}
+
+static void onPause(ANativeActivity* activity) {
+    LOGI("Pause: %p\n", activity);
+    android_app_set_activity_state((struct android_app*)activity->instance, APP_CMD_PAUSE);
+}
+
+static void onStop(ANativeActivity* activity) {
+    LOGI("Stop: %p\n", activity);
+    android_app_set_activity_state((struct android_app*)activity->instance, APP_CMD_STOP);
+}
+
+static void onLowMemory(ANativeActivity* activity) {
+    LOGI("LowMemory: %p\n", activity);
+}
+
+static void onWindowFocusChanged(ANativeActivity* activity, int focused) {
+    LOGI("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) {
+    LOGI("NativeWindowCreated: %p -- %p\n", activity, window);
+    android_app_set_window((struct android_app*)activity->instance, window);
+}
+
+static void onNativeWindowDestroyed(ANativeActivity* activity, ANativeWindow* window) {
+    LOGI("NativeWindowDestroyed: %p -- %p\n", activity, window);
+    android_app_set_window((struct android_app*)activity->instance, NULL);
+}
+
+static void onInputQueueCreated(ANativeActivity* activity, AInputQueue* queue) {
+    LOGI("InputQueueCreated: %p -- %p\n", activity, queue);
+    android_app_set_input((struct android_app*)activity->instance, queue);
+}
+
+static void onInputQueueDestroyed(ANativeActivity* activity, AInputQueue* queue) {
+    LOGI("InputQueueDestroyed: %p -- %p\n", activity, queue);
+    android_app_set_input((struct android_app*)activity->instance, NULL);
+}
+
+void ANativeActivity_onCreate(ANativeActivity* activity,
+        void* savedState, size_t savedStateSize) {
+    LOGI("Creating: %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->onLowMemory = onLowMemory;
+    activity->callbacks->onWindowFocusChanged = onWindowFocusChanged;
+    activity->callbacks->onNativeWindowCreated = onNativeWindowCreated;
+    activity->callbacks->onNativeWindowDestroyed = onNativeWindowDestroyed;
+    activity->callbacks->onInputQueueCreated = onInputQueueCreated;
+    activity->callbacks->onInputQueueDestroyed = onInputQueueDestroyed;
+
+    activity->instance = android_app_create(activity);
+}

ndk/sources/android/native_app_glue/android_native_app_glue.h

@@ -15,6 +15,9 @@
  *
  */
 
+#ifndef _ANDROID_NATIVE_APP_GLUE_H
+#define _ANDROID_NATIVE_APP_GLUE_H
+
 #include <poll.h>
 #include <pthread.h>
 #include <sched.h>
@@ -22,6 +25,60 @@
 #include <android/native_activity.h>
 #include <android/looper.h>
 
+#ifdef __cplusplus
+extern "C"
+#endif
+
+/**
+ * The native activity interface provided by <android/native_activity.h>
+ * is based on a set of application-provided callbacks that will be called
+ * by the Activity's main thread when certain events occur.
+ *
+ * This means that each one of this callbacks _should_ _not_ block, or they
+ * risk having the system force-close the application. This programming
+ * model is direct, lightweight, but constraining.
+ *
+ * The 'threaded_native_app' static library is used to provide a different
+ * execution model where the application can implement its own main event
+ * loop in a different thread instead. Here's how it works:
+ *
+ * 1/ The application must provide a function named "android_main()" that
+ *    will be called when the activity is created, in a new thread that is
+ *    distinct from the activity's main thread.
+ *
+ * 2/ android_main() receives a pointer to a valid "android_app" structure
+ *    that contains references to other important objects, e.g. the
+ *    ANativeActivity obejct instance the application is running in.
+ *
+ * 3/ the "android_app" object holds an ALooper instance that already
+ *    listens to two important things:
+ *
+ *      - activity lifecycle events (e.g. "pause", "resume"). See APP_CMD_XXX
+ *        declarations below.
+ *
+ *      - input events coming from the AInputQueue attached to the activity.
+ *
+ *    Each of these correspond to an ALooper callback that returns a "data"
+ *    value of LOOPER_ID_MAIN and LOOPER_ID_EVENT, respectively.
+ *
+ *    Your application can use the same ALooper to listen to additionnal
+ *    file-descriptors.
+ *
+ * 4/ Whenever you receive a LOOPER_ID_MAIN event from the ALooper, your
+ *    code should call the function android_app_read_cmd() to read the
+ *    command value and act upon it. This is normally done by calling
+ *    android_app_exec_cmd() directly.
+ *
+ *    XXX: MAKE THIS STUFF MORE CLEAR !!
+ *
+ * 5/ Whenever you receive a LOOPER_ID_EVENT event from the ALooper, you
+ *    should read one event from the AInputQueue with AInputQueue_getEvent().
+ *
+ * See the sample named "native-activity" that comes with the NDK with a
+ * full usage example.
+ *
+ */
+
 /**
  * This is the interface for the standard glue code of a threaded
  * application.  In this model, the application's code is running
@@ -195,3 +252,9 @@ int32_t android_app_exec_cmd(struct android_app* android_app, int8_t cmd);
  * the main entry to the app.
  */
 extern void android_main(struct android_app* app);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _ANDROID_NATIVE_APP_GLUE_H */