Address a crash when close is called from finalize.

[wongk]

On Android, finalize has 10 seconds to complete. SQLiteProgram.close is being called from finalize, and it does not consider whether it has already been closed before it tries to acquire the database lock. If the database is in use elsewhere, this can easily cause finalize to timeout, causing a fatal exception. This fixes the issue by making a second call to close a no-op.

[developernotes]

Hello @wongk,

Thank you for submitting this pull request. We ask that you submit a contributor agreement in order for us to accept this request. More information about this agreement can be found here. Please reach out to us at [email protected] for more information. Thanks!

[developernotes]

Hello @wongk

Also, is this something that you can prepare a test for which can be included in the SQLCipher for Android test suite?

[wongk]

@developernotes I am a VMware employee, and my request to have the CLA completed is currently working its way through "the machine."

[wongk]

@developernotes I will investigate the test suite. Thank you for the suggestion.

[wongk]

@developernotes I am having a good bit of trouble trying to build the test project. Since it appears to be a maven project, I am using the command 'mvn compile', and receiving the following error:

[ERROR] Failed to execute goal com.jayway.maven.plugins.android.generation2:maven-android-plugin:2.8.4:generate-sources (default-generate-sources) on project net.zetetic.sqlcipher.test: Execution default-generate-sources of goal com.jayway.maven.plugins.android.generation2:maven-android-plugin:2.8.4:generate-sources failed: Could not find tool 'aapt'. Please provide a proper Android SDK directory path as configuration parameter ... in the plugin . As an alternative, you may add the parameter to commandline: -Dandroid.sdk.path=... or set environment variable ANDROID_HOME. -> [Help 1]

I have set the ANDROID_HOME env variable to reflect my "command line tools" version of ADT, and also updated my PATH to pick up those tools first.

[developernotes]

Hello @wongk

Have you, or can you attempt to import the pom.xml as a project within IntelliJ to see if you are able to build the project through the IDE?

[wongk]

@developernotes I just tried that and instead received a number of 'cannot find symbol' errors related to generated resource classes (R).

[wongk]

Adding a local.properties and specifying 'sdk.dir' didn't seem to make any difference either.

[brody4hire]

I am afraid it would not be possible to reproduce the reported issue within the test suite since finalize is a protected method which is generally triggered by the Android system. I would personally favor including the proposed close guard along with a test that covers the changes. Some hints on adding to the test suite:

• Make a compiled statement test based on https://github.com/sqlcipher/sqlcipher-android-tests/blob/master/src/main/java/net/zetetic/tests/CompiledSQLUpdateTest.java that shows what happens if you close a SQLiteStatement (subclass of SQLiteProgram) and then try each of the updated methods
• I did something similar in https://github.com/sqlcipher/sqlcipher-android-tests/blob/master/src/main/java/net/zetetic/tests/ClosedDatabaseTest.java to verify what happens if someone executes many of the public SQLiteDatabase methods on a closed database.

I think the proposed changes along with test coverage would lead to more deterministic and tested behavior in this kind of scenario.

[wongk]

@brodybits Thanks for the direction and I am on the same page about test coverage. Unfortunately, I cannot build the tests, so I am unable to add new ones.

[wongk]

An update on this, we have the necessary approvals from within the organization, but we are having trouble getting the necessary executive to sign the CLA.

[g123k]

Hello,

I am using the latest version available (3.5.7) and I still have this issue in production.
Here is the 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)

[wongk]

Yes, my change specifically addressed SQLiteProgram, not SQLiteCompiledSql.

[g123k]

Ok, I will open a new issue for this one then.