SQLiteCompiledSql.finalize() timed out after 10 seconds

[g123k]

On Android with the latest version of SQLCipher (3.5.7), I have a huge amount of crashs on Crashlytics. It is similar to #313, but happens instead with the SQLiteCompiledSql class.

This is the full stacktrace:

Exception: java.util.concurrent.TimeoutException: net.sqlcipher.database.SQLiteCompiledSql.finalize() timed out after 10 seconds
at java.lang.Object.wait(Object.java)
at java.lang.Thread.parkFor(Thread.java:1205)
at sun.misc.Unsafe.park(Unsafe.java:325)
at java.util.concurrent.locks.LockSupport.park(LockSupport.java:
at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:813)
at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:846)
at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1175)
at java.util.concurrent.locks.ReentrantLock$FairSync.lock(ReentrantLock.java:195)
at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:256)
at net.sqlcipher.database.SQLiteDatabase.lock(SQLiteDatabase.java:553)
at net.sqlcipher.database.SQLiteCompiledSql.releaseSqlStatement(SQLiteCompiledSql.java:106)
at net.sqlcipher.database.SQLiteCompiledSql.finalize(SQLiteCompiledSql.java:152)
at java.lang.Daemons$FinalizerDaemon.doFinalize(Daemons.java:187)
at java.lang.Daemons$FinalizerDaemon.run(Daemons.java:170)
at java.lang.Thread.run(Thread.java:841)

[developernotes]

Hi @g123k

You might consider setting the PRAGMA busy_timeout to allow more time for the lock to reset. Would you try that and let us know your results? Thanks!

[g123k]

I have tried with 30 seconds and I don't know if the settings actually works, because I still have the same issue : net.sqlcipher.database.SQLiteCompiledSql.finalize() timed out after 10 seconds

Requesting the pragma returns a correct value however.

db.rawQuery("PRAGMA busy_timeout = 30000;", null)

[developernotes]

Hello @g123k

Are you still experiencing an issue? If so, are you able to reproduce it within the SQLCipher for Android test suite?

[developernotes]

Hello @g123k,

Since we have not heard back, I am going to close this ticket. If you still experiencing an issue we would be happy to investigate this further. Please fee free to open a new ticket and provide supporting information regarding your issue, preferably with a reproducible test case within the SQLCipher for Android test suite. Thanks!

[oleksandr-semenov]

Having the same issue, stacktrace:

    2021-02-15 13:31:15.099 E/AndroidRuntime: FATAL EXCEPTION: FinalizerWatchdogDaemon
    Process: com.xxx.yyy, PID: 4531
    java.util.concurrent.TimeoutException: net.sqlcipher.database.SQLiteCompiledSql.finalize() timed out after 10 seconds
        at java.lang.Object.wait(Native Method)
        at java.lang.Thread.parkFor$(Thread.java:2127)
        at sun.misc.Unsafe.park(Unsafe.java:325)
        at java.util.concurrent.locks.LockSupport.park(LockSupport.java:161)
        at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:840)
        at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:873)
        at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1197)
        at java.util.concurrent.locks.ReentrantLock$FairSync.lock(ReentrantLock.java:200)
        at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:262)
        at net.sqlcipher.database.SQLiteDatabase.lock(SQLiteDatabase.java:570)
        at net.sqlcipher.database.SQLiteCompiledSql.releaseSqlStatement(SQLiteCompiledSql.java:104)
        at net.sqlcipher.database.SQLiteCompiledSql.finalize(SQLiteCompiledSql.java:146)
        at java.lang.Daemons$FinalizerDaemon.doFinalize(Daemons.java:222)
        at java.lang.Daemons$FinalizerDaemon.run(Daemons.java:209)
        at java.lang.Thread.run(Thread.java:761)

I tried to reproduce that in unit tests, but I can't emulate all conditions
This happens 100% in our code on Android API 24-25 during concurrent work with DB. We don't have this issue without SQLCipher.
My guess would be that locking DB in finalize is error-prone, since finalize should be quick so that GC can collect data quickly.
Is it something that can be removed?

[developernotes]

Hello @oleksandr-semenov,

Thank you for your report. We too have been unable to reproduce finalize time out errors within the unit test suite. We plan to revisit the locking mechanics present within the library to evaluate whether removal or augmentation is more appropriate in a future release.

[oleksandr-semenov]

Hello @developernotes didn't see your reply and opened a new issue for this #537
I've created a synthetic test that reproduces this, maybe it can help to find the issue.