SQLiteDatabaseLockedException: database is locked (code 5) #191

KushGoyal · 2015-06-03T12:48:21Z

Some of my users are facing SQLiteDatabaseLockedException.

I am using this code in my application class onCreate method to setup database:

private void setupDatabase() {
        DbUpdateHelper helper = new DbUpdateHelper(this, "app-name-db", null);
        SQLiteDatabase db = helper.getWritableDatabase();
        DaoMaster daoMaster = new DaoMaster(db);
        daoSession = daoMaster.newSession();
    }

This is the only place where I am accessing the db using helper.getWritableDatabase().

Everywhere else I am using the daoSession object to access db.

Stacktrace:

java.lang.RuntimeException: Unable to create application o.ᴛ: android.database.sqlite.SQLiteDatabaseLockedException: database is locked (code 5): , while compiling: PRAGMA journal_mode
       at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4608)
       at android.app.ActivityThread.access$1500(ActivityThread.java:148)
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1353)
       at android.os.Handler.dispatchMessage(Handler.java:102)
       at android.os.Looper.loop(Looper.java:135)
       at android.app.ActivityThread.main(ActivityThread.java:5312)
       at java.lang.reflect.Method.invoke(Method.java)
       at java.lang.reflect.Method.invoke(Method.java:372)
       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:901)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:696)
Caused by: android.database.sqlite.SQLiteDatabaseLockedException: database is locked (code 5): , while compiling: PRAGMA journal_mode
       at android.database.sqlite.SQLiteConnection.nativePrepareStatement(SQLiteConnection.java)
       at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:889)
       at android.database.sqlite.SQLiteConnection.executeForString(SQLiteConnection.java:634)
       at android.database.sqlite.SQLiteConnection.setJournalMode(SQLiteConnection.java:320)
       at android.database.sqlite.SQLiteConnection.setWalModeFromConfiguration(SQLiteConnection.java:294)
       at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:215)
       at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:193)
       at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:463)
       at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:185)
       at android.database.sqlite.SQLiteConnectionPool.open(SQLiteConnectionPool.java:177)
       at android.database.sqlite.SQLiteDatabase.openInner(SQLiteDatabase.java:806)
       at android.database.sqlite.SQLiteDatabase.open(SQLiteDatabase.java:791)
       at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:694)
       at android.app.ContextImpl.openOrCreateDatabase(ContextImpl.java:1276)
       at android.content.ContextWrapper.openOrCreateDatabase(ContextWrapper.java:267)
       at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:223)
       at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:163)
       at o.ᴛ.onCreate(SourceFile:1032)
       at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1034)
       at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4605)
       at android.app.ActivityThread.access$1500(ActivityThread.java:148)
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1353)
       at android.os.Handler.dispatchMessage(Handler.java:102)
       at android.os.Looper.loop(Looper.java:135)
       at android.app.ActivityThread.main(ActivityThread.java:5312)
       at java.lang.reflect.Method.invoke(Method.java)
       at java.lang.reflect.Method.invoke(Method.java:372)
       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:901)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:696)

The text was updated successfully, but these errors were encountered:

Groxx · 2015-06-04T00:37:46Z

It probably means you're creating multiple DbUpdateHelper instances. You almost always only want to make one, ever.

KushGoyal · 2015-06-04T06:01:02Z

Hi,

Thanks for the help. Will using a singleton pattern solve this bug?

Groxx · 2015-06-04T20:57:07Z

If that's the cause, yes. I think you can (and should) just make a single DaoSession as well, so you can just make the session into a singleton. I forget exactly what goes into DaoSession though, so I could be wrong on that - check the docs :)

KushGoyal · 2015-06-05T07:18:12Z

I think I cannot make DbUpdateHelper singleton because the static instance will hold a reference to the context which will not get garbage collect until classloader has been unloaded which is I think almost never.

Is there any other solution I can implement to prevent multiple instances of DbUpdateHelper. Although I still don't understand how is it even possible that there are multiple instances of DbUpdateHelper since I am using the code in the application class and not anywhere else.

zhangsl · 2015-12-17T03:44:07Z

I got a similar crash, I have a singleton DatabaseHelper, and no transaction operation, but still crash

hwldzh · 2015-12-22T13:38:09Z

you can use context.getapplicationcontext, then the context can be collect by the garbage

michal-luszczuk · 2016-07-06T07:54:02Z

Did you solve this issue?
Because i'm also facing this problem.
App is crashing while first getWritableDatabasecall. And this call is done inside Application object. So nothing should be called before.

donghuipei · 2016-07-27T07:52:27Z

@michal-luszczuk
My issue is like you, I found the cause of the problem is a process that would correspond to a target application, if your application is configured with additional process, you might have multiple processes simultaneously open db operation, causing database locks abnormal.

michal-luszczuk · 2016-07-27T07:57:19Z

@donghuipei
Yeah, I've got same problem - multi-proces app related (database was initiated in Application class onCreate() method which was called by each process separately)

donghuipei · 2016-07-27T08:36:31Z

@michal-luszczuk
If only the main process in the application database operations there, while other applications related to the process does not require operation of the database, I recommend to initialize the database plus operating conditions, like this:

    if(getCurProcessName(getApplicationContext()).equals("replace your application package name")){
        // initialize the database
    }



private String getCurProcessName(Context context) {
    int pid = android.os.Process.myPid();
    ActivityManager activityManager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
    for (ActivityManager.RunningAppProcessInfo appProcess : activityManager.getRunningAppProcesses()) {
        if (appProcess.pid == pid) {
            return appProcess.processName;
        }
    }
    return "";
}

michal-luszczuk · 2016-07-27T08:41:20Z

@donghuipei
That's right (I did the same), and probably this is the best solution.
I think this answer will help many devs :)

ashalmawia · 2017-01-17T12:59:50Z

I wonder what's the solution in case if multiple processes need accessing the same SQLite database...

greenrobot-team · 2017-04-25T12:28:47Z

@artesa Based on a quick Google search using a ContentProvider is the common solution to access a (SQLite) database from another process/app. -ut

ashalmawia · 2017-05-08T12:45:12Z

@greenrobot-team Clever but nonconstructive, and I can explain why. SQLite documentation states that SQLite should support multiprocess access out-of-box. Using a ContentProvider is basically accessing SQLite database from a single process, while accessing the provider itself happens in a multiprocess manner. Therefore, it seems like the problem lies in Google's implementation of SQLiteOpenHelper, which makes multiprocess access done through it unreliable while you keep the connection open (and, of course, there is a plenty of other problems in case you don't).

I reached some progress in struggling with the issue, but still was not able to get rid of it completely. That's why I'm interested whether anyone was more successful.

BTW, I don't believe ContentProviders are actually a panacea. The library based on them which we used was generating even more errors on heavy loads than accessing SQLite directly. Was it the problem of the library? Maybe. But it's rather popular and we failed to find the reason in code, which itself makes providers either unreliable or hard to set up properly in some cases.

As a generalization of your comment I could add the following: based on a quick Google search (hint) dividing your app into multiple processes is strictly discouraged in principle. Yep, that's true. But, would this knowledge help me to deal with that huge ton of legacy? Don't think so. :)

hooby3dfx · 2017-06-05T22:26:32Z

I am also seeing this happen occasionally in an app that I work on, but the app is not designed to use multiple processes.
That being the case, when would this happen? Would that PID check still be useful?

nickylin · 2017-07-13T05:47:50Z

I'm occurred this problem, so we do not use greendao for multi process?
`

Thread Name: 'ModelWriteWorkThread'

| | Back traces starts.
| | android.database.sqlite.SQLiteDatabaseLockedException: database is locked (code 5)
| | at android.database.sqlite.SQLiteConnection.nativeExecuteForChangedRowCount(Native Method)
| | at android.database.sqlite.SQLiteConnection.executeForChangedRowCount(SQLiteConnection.java:915)
| | at android.database.sqlite.SQLiteSession.executeForChangedRowCount(SQLiteSession.java:755)
| | at android.database.sqlite.SQLiteStatement.executeUpdateDelete(SQLiteStatement.java:64)
| | at android.database.sqlite.SQLiteDatabase.executeSql(SQLiteDatabase.java:1771)

`

xurui1995 · 2017-08-03T07:23:34Z

@michal-luszczuk
I got the exception and i didnt use GreenDao.
Multiple processes were used in my app, but only one processes used Sqlite.
have u solve it?

michal-luszczuk · 2017-08-03T07:30:39Z

@xurui1995
Like I said before. Problem is solved for us.
The case was related to opening/initializing greenDao/sqlite db in code which was called by multiple processes.

You should check in which process code is called (using This comment ) and this should resolve your problems.

nickylin · 2017-08-14T03:16:50Z

if we need to read or write db in multi process, how we do to solve this problem? @michal-luszczuk @donghuipei

EnvySongtao · 2018-01-24T07:48:07Z

I have the similar crash，just becouse,I write self Application but forget to set appliaction name in manifest.xml

abduldblogger · 2018-01-31T09:19:25Z

Hi,
Use :
database = dbHelper.getWritableDatabase();
database.enableWriteAheadLogging(); // this will allow transactions from multiple threads.

Please read https://developer.android.com/reference/android/database/sqlite/SQLiteDatabase.html#enableWriteAheadLogging%28%29

I hope this will help.

gwheet · 2018-02-27T01:02:22Z

Found how to solve it. The problem for me was that I created multiple instances of SQLiteOpenHelper for the same database file from multiple threads. getWritableDatabase() contains synchronized block inside to prevent parallel access to internal open() method from multiple threads but because as I said there were multiple instances of SQLiteOpenHelper this lock didn't work. I created singleton from SQLiteOpenHelper. In order to release memory, I used WeakReference for "instance" field.
Also, you probably want to add enableWriteAheadLogging() in order to access db methods in parallel.

greenrobot added the Stack Overflow label Jun 27, 2015

greenrobot closed this as completed Jun 27, 2015

Repository owner deleted a comment from zxy198717 Nov 13, 2017

timobaehr mentioned this issue Jun 25, 2023

Failed to gain exclusive lock to the Cloud Firestore client's offline persistence. firebase/firebase-android-sdk#5001

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SQLiteDatabaseLockedException: database is locked (code 5) #191

SQLiteDatabaseLockedException: database is locked (code 5) #191

KushGoyal commented Jun 3, 2015

Groxx commented Jun 4, 2015

KushGoyal commented Jun 4, 2015

Groxx commented Jun 4, 2015

KushGoyal commented Jun 5, 2015

zhangsl commented Dec 17, 2015

hwldzh commented Dec 22, 2015

michal-luszczuk commented Jul 6, 2016

donghuipei commented Jul 27, 2016

michal-luszczuk commented Jul 27, 2016 •

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donghuipei commented Jul 27, 2016 •

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michal-luszczuk commented Jul 27, 2016

ashalmawia commented Jan 17, 2017

greenrobot-team commented Apr 25, 2017 •

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ashalmawia commented May 8, 2017

hooby3dfx commented Jun 5, 2017

nickylin commented Jul 13, 2017

xurui1995 commented Aug 3, 2017

michal-luszczuk commented Aug 3, 2017

nickylin commented Aug 14, 2017 •

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EnvySongtao commented Jan 24, 2018

abduldblogger commented Jan 31, 2018

gwheet commented Feb 27, 2018 •

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SQLiteDatabaseLockedException: database is locked (code 5) #191

SQLiteDatabaseLockedException: database is locked (code 5) #191

Comments

KushGoyal commented Jun 3, 2015

Groxx commented Jun 4, 2015

KushGoyal commented Jun 4, 2015

Groxx commented Jun 4, 2015

KushGoyal commented Jun 5, 2015

zhangsl commented Dec 17, 2015

hwldzh commented Dec 22, 2015

michal-luszczuk commented Jul 6, 2016

donghuipei commented Jul 27, 2016

michal-luszczuk commented Jul 27, 2016 • edited Loading

donghuipei commented Jul 27, 2016 • edited Loading

michal-luszczuk commented Jul 27, 2016

ashalmawia commented Jan 17, 2017

greenrobot-team commented Apr 25, 2017 • edited Loading

ashalmawia commented May 8, 2017

hooby3dfx commented Jun 5, 2017

nickylin commented Jul 13, 2017

Thread Name: 'ModelWriteWorkThread'

xurui1995 commented Aug 3, 2017

michal-luszczuk commented Aug 3, 2017

nickylin commented Aug 14, 2017 • edited Loading

EnvySongtao commented Jan 24, 2018

abduldblogger commented Jan 31, 2018

gwheet commented Feb 27, 2018 • edited Loading

michal-luszczuk commented Jul 27, 2016 •

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donghuipei commented Jul 27, 2016 •

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greenrobot-team commented Apr 25, 2017 •

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nickylin commented Aug 14, 2017 •

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gwheet commented Feb 27, 2018 •

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