Question Multithreaded Rendering JNI C++ to call Java function not work

I want to use Unity to render the resources in my Android and control the logic on the Android device. I have adopted the following structure. It normal work at the single thread but not work at Multithreaded rendering. I want the architecture normal run at Multithreaded rendering, so i want to use GL.IssuePluginEvent to run at rendering thread.

My C# code is

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using UnityEngine.UI;
5. using System;
6. using AOT;
7. using System.Runtime.InteropServices;
8.  
9. public class Main : MonoBehaviour
10. {
11.  
12.     private AndroidJavaObject nativeObject;
13.     private static int width, height;
14.     public MeshRenderer meshRenderer;
15.     private Texture2D texture;
16.     private delegate void RenderEventDelegate(int eventID);
17.     private RenderEventDelegate RenderThreadHandle;
18.     private IntPtr RenderThreadHandlePtr;
19.     private static int texturePtr;
20.  
21.     void Awake()
22.     {
23.         RenderThreadHandle = new RenderEventDelegate(RunOnRenderThread);
24.         RenderThreadHandlePtr = Marshal.GetFunctionPointerForDelegate(RenderThreadHandle);
25.     }
26.  
27.     // Use this for initialization
28.     void Start()
29.     {
30.         Debug.Log("OnStart");
31.         AndroidJavaClass jc = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
32.         AndroidJavaObject jo = jc.GetStatic<AndroidJavaObject>("currentActivity");
33.         nativeObject = new AndroidJavaObject("com.pvr.videoplugin.VideoPlugin", jo);
34.         width = 1600;
35.         height = 900;
36.         Debug.Log("VideoPlugin:" + width + ", " + height);
37.  
38.         nativeObject.CallStatic("loadLib");
39.  
40.         nativeObject.Call("initObject");
41.  
42.         if (SystemInfo.graphicsMultiThreaded)
43.         {
44.             Debug.Log("VideoPlugin:Start");
45.             texture = new Texture2D(width, height, TextureFormat.RGB24, false, false);
46.             texturePtr = (int)texture.GetNativeTexturePtr();
47.             GL.IssuePluginEvent(RenderThreadHandlePtr, GL_INIT_EVENT);
48.             meshRenderer.material.mainTexture = texture;
49.         }
50.         else
51.         {
52.             Debug.Log("VideoPlugin:Start");
53.             texture = new Texture2D(width, height, TextureFormat.RGB24, false, false);
54.             texturePtr = (int)texture.GetNativeTexturePtr();
55.             RunOnRenderThread(GL_INIT_EVENT);
56.             meshRenderer.material.mainTexture = texture;
57.         }
58.     }
59.  
60.     private void OnDisable()
61.     {
62.         Debug.Log("OnDisable");
63.         if (SystemInfo.graphicsMultiThreaded)
64.         {
65.             texture = null;
66.             meshRenderer.material.mainTexture = null;
67.             GL.IssuePluginEvent(RenderThreadHandlePtr, GL_DESTROY_EVENT);
68.         }
69.         else
70.         {
71.             texture = null;
72.             meshRenderer.material.mainTexture = null;
73.             RunOnRenderThread(GL_DESTROY_EVENT);
74.         }
75.     }
76.    
77.     void Update()
78.     {
79.         if (SystemInfo.graphicsMultiThreaded)
80.         {
81.             GL.IssuePluginEvent(RenderThreadHandlePtr, GL_UPDATE_EVENT);
82.             GL.InvalidateState();
83.         }
84.         else
85.         {
86.             RunOnRenderThread(GL_UPDATE_EVENT);
87.             GL.InvalidateState();
88.         }
89.     }
90.    
91.     private void updateTexutreCsharp()
92.     {
93.         if (texture != null && nativeObject.Call<bool>("isUpdateFrame"))
94.         {
95.             Debug.Log("VideoPlugin:Update");
96.             updateTexture();
97.             //nativeObject.Call("updateTexture");
98.             GL.InvalidateState();
99.         }
100.     }
101.    
102.     private void createTexture()
103.     {
104.         Debug.Log("VideoPlugin:Start");
105.         texture = new Texture2D(width, height, TextureFormat.RGB24, false, false);
106.         start((int)texture.GetNativeTexturePtr(), width, height);
107.         // nativeObject.Call("start", (int)texture.GetNativeTexturePtr(), width, height);
108.         meshRenderer.material.mainTexture = texture;
109.     }
110.    
111.     private void destroyTexture()
112.     {
113.         Debug.Log("VideoPlugin:Release");
114.         texture = null;
115.         meshRenderer.material.mainTexture = null;
116.         release();
117.         //nativeObject.Call("release");
118.     }
119.    
120.     private const int GL_INIT_EVENT = 0x0001;
121.     private const int GL_UPDATE_EVENT = 0x0002;
122.     private const int GL_DESTROY_EVENT = 0x0003;
123.     [MonoPInvokeCallback(typeof(RenderEventDelegate))]
124.     private static void RunOnRenderThread(int eventID)
125.     {
126.         switch (eventID)
127.         {
128.             case GL_INIT_EVENT:
129.                 start(texturePtr, width, height);
130.                 break;
131.             case GL_UPDATE_EVENT:
132.                 updateTexture();
133.                 break;
134.             case GL_DESTROY_EVENT:
135.                 release();
136.                 break;
137.         }
138.     }
139.  
140.     [DllImport("application")]
141.     private static extern void start(int unityTextureId, int width, int height);
142.  
143.     [DllImport("application")]
144.     private static extern void release();
145.  
146.     [DllImport("application")]
147.     private static extern void updateTexture();
148. }
149.  

C++ code is

Code (CSharp):

1. #include "jni.h"
2. #include <android/log.h>
3. #include <cstdio>
4. #include <pthread.h>
5. #include <unistd.h>
6.  
7. #define ehome_printf(format, ...)  \
8.     __android_log_print(ANDROID_LOG_DEBUG,  "jni_debug", format, ##__VA_ARGS__)
9.  
10. static JavaVM *ms2_vm = NULL;
11. static jobject g_obj;
12.  
13. JNIEXPORT jint JNICALL JNI_OnLoad(JavaVM* vm, void* reserved)
14. {
15.     ms2_vm = vm;
16.     ehome_printf("[%s]getpid=%d, gettid=%d\n", __FUNCTION__, getpid(),gettid());
17.     return JNI_VERSION_1_4;
18. }
19.  
20. extern "C"
21. {
22.     bool get_env(JNIEnv ** env) {
23.         int status = ms2_vm->GetEnv((void**) env, JNI_VERSION_1_4);
24.         if (status != JNI_OK) {
25.             ehome_printf("[%s]getpid=%d, gettid=%d\n", __FUNCTION__, getpid(),gettid());
26.             status = ms2_vm->AttachCurrentThread(env, NULL);
27.             if(status != JNI_OK){
28.                 ehome_printf("[%s]FAILED\n", __FUNCTION__);
29.                 return false;
30.             }
31.             ehome_printf("[%s]SUCCESS\n", __FUNCTION__);
32.         }else{
33.             ehome_printf("[%s]Attach aready\n", __FUNCTION__);
34.         }
35.         return true;
36.     }
37.  
38.     void release_env(void) {
39.         JNIEnv *env ;
40.         int status = ms2_vm->GetEnv((void**)&env, JNI_VERSION_1_4);
41.         if (status == JNI_EDETACHED) {
42.             ehome_printf("[%s]getpid=%d, gettid=%d\n", __FUNCTION__, getpid(),gettid());
43.             ms2_vm->DetachCurrentThread();
44.             ehome_printf("Release success");
45.         }else{
46.             ehome_printf("[%s]NEED NOT DETACH\n", __FUNCTION__);
47.         }
48.     }
49.  
50.     void start(int unityTextureId, int width, int height)
51.     {
52.         ehome_printf("start function is start");
53.         JNIEnv *env;
54.         ehome_printf("get env start");
55.         if (!get_env(&env)) {
56.             ehome_printf("[%s]get_env error!\n", __FUNCTION__);
57.             return;
58.         }
59.         ehome_printf("[%s]GetVersion=%d\n", __FUNCTION__, env->GetVersion());
60.  
61.         jclass clazz = env->FindClass("com/pvr/videoplugin/VideoPlugin");
62.         ehome_printf("FindClass end");
63.         jmethodID mt = env->GetMethodID(clazz, "start", "(III)V");
64.         ehome_printf("GetMethodID end");
65.         env->CallVoidMethod(g_obj, mt, unityTextureId, width, height);
66.         ehome_printf("CallVoidMethod end");
67.  
68.         release_env();
69.         ehome_printf("start function is end");
70.     }
71.  
72.     void release()
73.     {
74.         ehome_printf("release function is start");
75.         JNIEnv *env;
76.         if (!get_env(&env)) {
77.             ehome_printf("[%s]get_env error!\n", __FUNCTION__);
78.             return;
79.         }
80.         ehome_printf("[%s]GetVersion=%d\n", __FUNCTION__, env->GetVersion());
81.  
82.         jclass clazz = env->FindClass("com/pvr/videoplugin/VideoPlugin");
83.         jmethodID mt = env->GetMethodID(clazz, "release", "()V");
84.         env->CallVoidMethod(g_obj, mt);
85.  
86.         // release_env();
87.         ehome_printf("release function is end");
88.     }
89.  
90.     void updateTexture()
91.     {
92.         ehome_printf("updateTexture function is start");
93.         JNIEnv *env;
94.         if (!get_env(&env)) {
95.             ehome_printf("[%s]get_env error!\n", __FUNCTION__);
96.             return;
97.         }
98.         ehome_printf("[%s]GetVersion=%d\n", __FUNCTION__, env->GetVersion());
99.  
100.         jclass clazz = env->FindClass("com/pvr/videoplugin/VideoPlugin");
101.         jmethodID mt = env->GetMethodID(clazz, "updateTexture", "()V");
102.         env->CallVoidMethod(g_obj, mt);
103.  
104.         // release_env();
105.         ehome_printf("updateTexture function is end");
106.     }
107. }
108.  
109. extern "C" JNIEXPORT void JNICALL
110. Java_com_pvr_videoplugin_VideoPlugin_initObject(
111.         JNIEnv* env,
112. jobject obj) {
113.     ehome_printf("InitObject Function is run");
114.     g_obj = env->NewGlobalRef(obj);
115. }

My java code is

Code (CSharp):

1. package com.pvr.videoplugin;
2.  
3. import android.app.Activity;
4. import android.content.res.AssetFileDescriptor;
5. import android.graphics.SurfaceTexture;
6. import android.graphics.SurfaceTexture.OnFrameAvailableListener;
7. import android.media.AudioManager;
8. import android.media.MediaPlayer;
9. import android.net.Uri;
10. import android.view.Surface;
11.  
12. import java.io.File;
13. import java.io.IOException;
14.  
15. public class VideoPlugin implements OnFrameAvailableListener {
16.  
17.     private final Activity mActivity;
18.     private SurfaceTexture mSurfaceTexture;
19.     private Surface mSurface;
20.     private FilterFBOTexture mFilterFBOTexture;
21.     private MediaPlayer mMediaPlayer;
22.     private boolean mIsUpdateFrame;
23.  
24.     public VideoPlugin(Activity activity) {
25.         FBOUtils.log("VideoPlugin is start");
26.         mActivity = activity;
27.         FBOUtils.log("VideoPlugin is end");
28.     }
29.  
30.     public void start(int unityTextureId, int width, int height) {
31.         FBOUtils.log("start, unityTextureId=" + unityTextureId);
32.  
33.         int videoTextureId = FBOUtils.createOESTextureID();
34.  
35.         mSurfaceTexture = new SurfaceTexture(videoTextureId);
36.         mSurfaceTexture.setDefaultBufferSize(width, height);
37.         mSurfaceTexture.setOnFrameAvailableListener(this);
38.  
39.         mSurface = new Surface(mSurfaceTexture);
40.  
41.         mFilterFBOTexture = new FilterFBOTexture(width, height, unityTextureId, videoTextureId);
42.  
43.         initMediaPlayer();
44.     }
45.  
46.     public void release() {
47.         FBOUtils.log("release");
48.         if (mMediaPlayer != null) {
49.             mMediaPlayer.stop();
50.             mMediaPlayer.reset();
51.             mMediaPlayer.release();
52.             mMediaPlayer = null;
53.         }
54.         if (mSurface != null) {
55.             mSurface.release();
56.             mSurface = null;
57.         }
58.         if (mSurfaceTexture != null) {
59.             mSurfaceTexture.release();
60.             mSurfaceTexture = null;
61.         }
62.         if (mFilterFBOTexture != null) {
63.             mFilterFBOTexture.release();
64.             mFilterFBOTexture = null;
65.         }
66.         mIsUpdateFrame = false;
67.     }
68.  
69.     private void initMediaPlayer() {
70.         mMediaPlayer = new MediaPlayer();
71.         mMediaPlayer.setSurface(mSurface);
72.         try {
73.             AssetFileDescriptor fd = mActivity.getAssets().openFd("test.mp4");
74. //            final File file = new File("/sdcard/test.mp4");
75.             mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
76.             mMediaPlayer.setLooping(true);
77. //            mMediaPlayer.setDataSource(Uri.fromFile(file).toString());
78.             mMediaPlayer.setDataSource(fd.getFileDescriptor(), fd.getStartOffset(), fd.getLength());
79.             mMediaPlayer.prepareAsync();
80.         } catch (IOException e) {
81.             e.printStackTrace();
82.         }
83.         mMediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
84.             @Override
85.             public void onPrepared(MediaPlayer mp) {
86.                 FBOUtils.log("MediaPlayer onPrepared");
87.                 mMediaPlayer.start();
88.             }
89.         });
90.     }
91.  
92.     @Override
93.     public void onFrameAvailable(SurfaceTexture surfaceTexture) {
94.         FBOUtils.log("onFrameAvailable");
95.         mIsUpdateFrame = true;
96.     }
97.  
98.     public void updateTexture() {
99.         FBOUtils.log("updateTexture");
100.         mIsUpdateFrame = false;
101.         mSurfaceTexture.updateTexImage();
102.         mFilterFBOTexture.draw();
103.     }
104.  
105.     public boolean isUpdateFrame() {
106.         return mIsUpdateFrame;
107.     }
108.  
109.     // native function
110.     public native void initObject();
111.  
112. //    static {
113. //        System.loadLibrary("application");
114. //    }
115.  
116.     public static void loadLib() {
117.         System.loadLibrary("application");
118.         FBOUtils.log("Lod .so end");
119.     }
120. }
121.  

my Unity setting is

 

the logcat is this


Failed to load native plugin: Unable to load library '/data/app/com.pvr.easy-wpe-VykhgfdNXpjQCBa40Q==/lib/arm/libapplication.so', error 'java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.ClassLoader java.lang.Class.getClassLoader()' on a null object reference'

 

How can I deal with this problem.thanks

 

Yes, the failure occurs when i use unity render thread AttachCurrentThread and env->FindClass env->GetMethodID. The error not occur at unity Main Thread.

I tried to use AndroidJNI.FindClass but seem not work, I don't know how to use it in detail in my project

How can i use AndroidJNI.FindClass, should i find the class at unity and send it to JNI？

 

thanks, this bug has been solved. I use a global ref.

 

Hello, I have a question, now I call AndroidJNI.FindClass and AndroidJNI.NewGlobalRef in the c# layer, should this new variable be set as global? And I'm a novice, would like to ask how c# should pass this variable to the c++ layer, thank you very much, if you can guide me, I will be very grateful