E/REALM: jni: ThrowingException 5，mmap()失败:内存大小: 369098752

Question

我试图将大型json文件下载到领域数据库中。loadCarbay()做得很好，但是checkTyres()在Realm.getDefaultInstance()上抛出内存异常

我检查了关闭实例时的所有领域代码--一切都很好。我检查了getLocalInstanceCount() -它在崩溃前返回0。我不明白我做错了什么？

void checkLoadData(){
        final boolean hasCarbay = hasCarbay();
        final boolean hasTyres = hasTyres();

        if(!hasPersons()||!hasModels()||!hasDeparts()||!hasCarbay||!hasTyres){
            if(checkWifi(this)){
                if(!progressDialog.isShowing())progressDialog.show();
                Thread t = new Thread(new Runnable() {
                    public void run() {
                        final String holding = ses.getString("holding_url");
                        final String curr = ses.getString("curBaseAAURL");
                        loadBase(holding,curr,"");
                        if(!hasPersons()) {
                            h.sendEmptyMessage(STATUS_LOADING_PERSONS_START);
                            loadTablePersons(LoginPageActivity.this, h, STATUS_LOADING_PERSONS_PROGRESS, STATUS_LOADING_PERSONS_END);
                            loadTopicsFromJson(LoginPageActivity.this);
                        }
                        if(!hasModels()){
                            h.sendEmptyMessage(STATUS_LOADING_MODELS_START);
                            loadAlfaModels(LoginPageActivity.this,h,STATUS_LOADING_ALFA_PROGRESS,STATUS_LOADING_ALFA_END);
                        }
                        if(!hasDeparts()){
                            h.sendEmptyMessage(STATUS_LOADING_WS_LINKS_START);
                            loadDepartments(LoginPageActivity.this);
                            h.sendEmptyMessage(STATUS_LOADING_WS_LINKS_END);
                        }
                        if(!hasCarbay){
                            h.sendEmptyMessage(STATUS_LOADING_CARBAY_START);
                            loadCarbayData(LoginPageActivity.this,h,STATUS_LOADING_CARBAY_END);
                            h.sendEmptyMessage(STATUS_LOADING_CARBAY_END);
                        }
                        if(!hasTyres){
                            h.sendEmptyMessage(STATUS_LOADING_TYRE_START);
                            loadTyres(LoginPageActivity.this,h,STATUS_LOADING_TYRE_END);

                        }
                        h.sendEmptyMessage(STATUS_LOADING_TYRE_END);

                    }
                }
                );
                t.start();
            }
            }

    }

    private boolean hasCarbay(){

        Realm realm = Realm.getDefaultInstance();
        long count = realm.where(CarbayBrand.class)
                .count();
        boolean f = count>0;
        realm.close();

        return f;
    }

    private boolean hasTyres(){
        boolean flag = false;
        Realm realm = Realm.getDefaultInstance();

        try{
            long count = realm.where(Tyre.class).count();
            if(count>0){
                Tyre t = realm.where(Tyre.class).findFirst();
                if(t!=null){
                    if(t.getUid()!=null && !t.getUid().isEmpty()){
                        flag = true;
                    }
                }

            }
            Log.d("hasTyre","count="+count);
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            realm.close();
        }



        return flag;
    }

//loading data to realm

    synchronized void loadCarbayData(Context context, Handler h, int LOADING_END){
        GlobalParams globalParams = new GlobalParams(context);

        final String url1 = "http://" + globalParams.storage_url + "/carbay/car_bay_data.txt";
        final String url2 =  "http://" + globalParams.storage_url + "/carbay/carbay_ref1.json";
        final String url3 =  "http://" + globalParams.storage_url + "/carbay/carbay_ref2.json";
        final String url4 =  "http://" + globalParams.storage_url + "/carbay/carbay_ref3.json";

        //Log.d("JsonGet", "Realm closed! Realm instances="+Realm.getLocalInstanceCount(Realm.getDefaultConfiguration()));

        Realm realm = Realm.getDefaultInstance();

        try{
            realm.executeTransaction(new Realm.Transaction() {
                @Override
                public void execute(Realm realm) {
                    realm.delete(TradeInCarbay.class);
                }
            });
            realm.executeTransaction(new Realm.Transaction() {
                @Override
                public void execute(Realm realm) {
                    realm.delete(CarbayBrand.class);
                }
            });
            realm.executeTransaction(new Realm.Transaction() {
                @Override
                public void execute(Realm realm) {
                    realm.delete(CarbayModels.class);
                }
            });
            realm.executeTransaction(new Realm.Transaction() {
                @Override
                public void execute(Realm realm) {
                    realm.delete(CarbayModifications.class);
                }
            });
            realm.executeTransaction(new Realm.Transaction() {
                @Override
                public void execute(Realm realm) {
                    realm.delete(CarbayDataLink.class);
                }
            });
            // Insert multiple items using an InputStream
            Log.d("JsonGet", "Старт загрузки справочника Карбей");
            realm.executeTransaction(new Realm.Transaction() {
                @Override
                public void execute(Realm realm) {
                    try {
                        URL url = new URL(url1);
                        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                        connection.connect();
                        InputStream stream = connection.getInputStream();
                        realm.createAllFromJson(TradeInCarbay.class, stream);
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            });

            Log.d("JsonGet", "Старт загрузки регистра Карбей ч1");

            // Insert multiple items using an InputStream

            realm.executeTransaction(new Realm.Transaction() {
                @Override
                public void execute(Realm realm) {
                    try {
                        URL url = new URL(url2);
                        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                        connection.connect();
                        InputStream stream = connection.getInputStream();
                        realm.createAllFromJson(CarbayBrand.class, stream);
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            });


            Log.d("JsonGet", "Старт загрузки регистра Карбей ч2");

            realm.executeTransaction(new Realm.Transaction() {
                @Override
                public void execute(Realm realm) {
                    try {
                        URL url = new URL(url3);
                        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                        connection.connect();
                        InputStream stream = connection.getInputStream();
                        realm.createAllFromJson(CarbayBrand.class, stream);
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            });


            Log.d("JsonGet", "Старт загрузки регистра Карбей ч3");

            realm.executeTransaction(new Realm.Transaction() {
                @Override
                public void execute(Realm realm) {
                    try {
                        URL url = new URL(url4);
                        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                        connection.connect();
                        InputStream stream = connection.getInputStream();
                        realm.createAllFromJson(CarbayBrand.class, stream);
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            });
        }catch (Exception e){
            e.printStackTrace();
        }
        finally {
            realm.close();
            //Log.d("JsonGet", "Realm closed! Realm instances="+Realm.getLocalInstanceCount(Realm.getDefaultConfiguration()));
        }



        Message msg;
        msg = h.obtainMessage(LOADING_END, 0, 0);
        h.sendMessage(msg);
    }

    synchronized void loadTyres(Context context, Handler h, int LOADING_END){
        GlobalParams globalParams = new GlobalParams(context);

        final String url1 = "http://" + globalParams.storage_url + "/get_tyres_v2.php";

        Log.d("JsonGet", "Старт загрузки справочника шин");

        try(Realm realm = Realm.getDefaultInstance()) {
            realm.executeTransaction(new Realm.Transaction() {
                @Override
                public void execute(Realm realm) {
                    realm.delete(Tyre.class);
                }
            });

            // Insert multiple items using an InputStream
            realm.executeTransaction(new Realm.Transaction() {
                @Override
                public void execute(Realm realm) {
                    try {
                        URL url = new URL(url1);
                        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                        connection.connect();
                        InputStream stream = connection.getInputStream();
                        realm.createAllFromJson(Tyre.class, stream);
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            });
        }catch (Exception e){
            e.printStackTrace();
        }

        Message msg;
        msg = h.obtainMessage(LOADING_END, 0, 0);
        h.sendMessage(msg);
    }

我的logcat错误消息

2019-07-12 15:05:09.347 11321-11362/com.lx2.crm E/REALM_JNI: jni: ThrowingException 5, mmap() failed: Out of memory size: 369098752 offset: 0 in /Users/Nabil/Dev/realm/master/realm-java/realm/realm-library/src/main/cpp/io_realm_internal_OsSharedRealm.cpp line 101, .
2019-07-12 15:05:09.350 11321-11362/com.lx2.crm E/REALM_JNI: Exception has been thrown: Unrecoverable error. mmap() failed: Out of memory size: 369098752 offset: 0 in /Users/Nabil/Dev/realm/master/realm-java/realm/realm-library/src/main/cpp/io_realm_internal_OsSharedRealm.cpp line 101
2019-07-12 15:05:09.352 11321-11362/com.lx2.crm E/AndroidRuntime: FATAL EXCEPTION: Thread-10
    Process: com.lx2.crm, PID: 11321
    io.realm.exceptions.RealmError: Unrecoverable error. mmap() failed: Out of memory size: 369098752 offset: 0 in /Users/Nabil/Dev/realm/master/realm-java/realm/realm-library/src/main/cpp/io_realm_internal_OsSharedRealm.cpp line 101
        at io.realm.internal.OsSharedRealm.nativeGetSharedRealm(Native Method)
        at io.realm.internal.OsSharedRealm.<init>(OsSharedRealm.java:184)
        at io.realm.internal.OsSharedRealm.getInstance(OsSharedRealm.java:254)
        at io.realm.internal.OsSharedRealm.getInstance(OsSharedRealm.java:244)
        at io.realm.RealmCache.doCreateRealmOrGetFromCache(RealmCache.java:319)
        at io.realm.RealmCache.createRealmOrGetFromCache(RealmCache.java:282)
        at io.realm.Realm.getDefaultInstance(Realm.java:332)
        at com.lx2.crm.LoginPageActivity.loadTyres(LoginPageActivity.java:1154)
        at com.lx2.crm.LoginPageActivity$11.run(LoginPageActivity.java:1001)
        at java.lang.Thread.run(Thread.java:764)

Answer 1

它看起来像没有释放内存的领域，直到异步任务还没有完成。这就是为什么当我试图分割文件im加载时，内存出现错误的原因。我的解决方案是划分加载文件并为每个文件创建异步任务。在以前的任务中，每个异步任务都通过回调启动。有点丑，但很管用

Answer 2

Ilshat，欢迎来到StackOverflow。

loadTyres()的一个不同之处在于它使用的是一条具有资源的试用语句：

try(Realm realm = Realm.getDefaultInstance()) { 

而loadCarbay()不是：

Realm realm = Realm.getDefaultInstance();
try{ 

可能领域不兼容使用资源的尝试语句。尝试让loadCarbay()在try块之前获取领域实例，以查看这是否解决了问题。这只是猜测而已。

如果这样做，请记住使用realm.close();添加一个最终块

Answer 3

我发现为什么每当我得到实例时领域崩溃--在我的设备中内存不足。我在另一个内存很大的设备上安装了我的应用程序，一切都很好。