Do not execute blocking operations in the main thread in Downloads #1636
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StrictMode is most commonly used to catch accidental disk or network access on the application's main thread, where UI operations are received and animations take place. Keeping disk and network operations off the main thread makes for much smoother, more responsive applications[1]. [1] https://developer.android.com/reference/android/os/StrictMode
SettingsStore used to call editor.commit() to apply the value of a setting and write it to disk. That should not be done in the main thread though as it's a blocking operation. It's better to use apply() which atomically modifies the SharedPreferences object in memory and then uses a background thread to write it to disk. It's safe to replace commit() by apply() as long as the return value is not used, which is the case. This fixes reports like: D StrictMode policy violation; ~duration=3 ms: android.os.strictmode.DiskWriteViolation at android.os.StrictMode$AndroidBlockGuardPolicy.onWriteToDisk(StrictMode.java:1615) at libcore.io.BlockGuardOs.write(BlockGuardOs.java:446) at libcore.io.ForwardingOs.write(ForwardingOs.java:951) at libcore.io.IoBridge.write(IoBridge.java:649) at java.io.FileOutputStream.write(FileOutputStream.java:401) at com.android.internal.util.FastXmlSerializer.flushBytes(FastXmlSerializer.java:253) at com.android.internal.util.FastXmlSerializer.flush(FastXmlSerializer.java:274) at com.android.internal.util.FastXmlSerializer.endDocument(FastXmlSerializer.java:219) at com.android.internal.util.XmlSerializerWrapper.endDocument(XmlSerializerWrapper.java:68) at com.android.internal.util.XmlUtils.writeMapXml(XmlUtils.java:408) at android.app.SharedPreferencesImpl.writeToFile(SharedPreferencesImpl.java:803) at android.app.SharedPreferencesImpl.access$900(SharedPreferencesImpl.java:59) at android.app.SharedPreferencesImpl$2.run(SharedPreferencesImpl.java:672) at android.app.SharedPreferencesImpl.enqueueDiskWrite(SharedPreferencesImpl.java:691) at android.app.SharedPreferencesImpl.access$100(SharedPreferencesImpl.java:59) at android.app.SharedPreferencesImpl$EditorImpl.commit(SharedPreferencesImpl.java:604) at com.igalia.wolvic.browser.SettingsStore.resetCrashRestartCount(SettingsStore.java:766) at com.igalia.wolvic.VRBrowserActivity.lambda$onCreate$0$com-igalia-wolvic-VRBrowserActivity(VRBrowserActivity.java:296) at com.igalia.wolvic.VRBrowserActivity$$ExternalSyntheticLambda3.run(D8$$SyntheticClass:0) at android.os.Handler.handleCallback(Handler.java:938) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loopOnce(Looper.java:214) at android.os.Looper.loop(Looper.java:304) at android.app.ActivityThread.main(ActivityThread.java:7918) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1010)
Quering the list of downloads might involve SQL queries that can write to a file. That's a blocking operation that should not happen in the main thread. Instead get the diskIO executor in the constructor and use it to run the query. Note that notifications to listeners should still happen in the main thread. This fixes this report: D StrictMode policy violation; ~duration=38 ms: android.os.strictmode.DiskWriteViolation at android.os.StrictMode$AndroidBlockGuardPolicy.onWriteToDisk(StrictMode.java:1615) at android.database.sqlite.SQLiteConnection.applyBlockGuardPolicy(SQLiteConnection.java:1201) at android.database.sqlite.SQLiteConnection.executeForString(SQLiteConnection.java:794) at android.database.sqlite.SQLiteConnection.setJournalMode(SQLiteConnection.java:407) at android.database.sqlite.SQLiteConnection.setWalModeFromConfiguration(SQLiteConnection.java:347) at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:260) at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:205) at android.database.sqlite.SQLiteConnectionPool.openConnectionLocked(SQLiteConnectionPool.java:505) at android.database.sqlite.SQLiteConnectionPool.tryAcquireNonPrimaryConnectionLocked(SQLiteConnectionPool.java:989) at android.database.sqlite.SQLiteConnectionPool.waitForConnection(SQLiteConnectionPool.java:695) at android.database.sqlite.SQLiteConnectionPool.acquireConnection(SQLiteConnectionPool.java:380) at android.database.sqlite.SQLiteSession.acquireConnection(SQLiteSession.java:896) at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588) at android.database.sqlite.SQLiteDatabase.validateSql(SQLiteDatabase.java:1945) at android.database.sqlite.SQLiteQueryBuilder.query(SQLiteQueryBuilder.java:573) at android.database.sqlite.SQLiteQueryBuilder.query(SQLiteQueryBuilder.java:463) at com.android.providers.downloads.DownloadProvider.query(DownloadProvider.java:1270) at android.content.ContentProvider.query(ContentProvider.java:1408) at android.content.ContentProvider.query(ContentProvider.java:1504) at android.content.ContentProvider$Transport.query(ContentProvider.java:272) at android.content.ContentProviderNative.onTransact(ContentProviderNative.java:107) at android.os.Binder.execTransactInternal(Binder.java:1179) at android.os.Binder.execTransact(Binder.java:1143) at android.os.StrictMode.readAndHandleBinderCallViolations(StrictMode.java:2497) at android.os.Parcel.readExceptionCode(Parcel.java:2371) at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:139) at android.content.ContentProviderProxy.query(ContentProviderNative.java:481) at android.content.ContentResolver.query(ContentResolver.java:1219) at android.content.ContentResolver.query(ContentResolver.java:1151) at android.content.ContentResolver.query(ContentResolver.java:1107) at android.app.DownloadManager$Query.runQuery(DownloadManager.java:1019) at android.app.DownloadManager.query(DownloadManager.java:1165) at android.app.DownloadManager.query(DownloadManager.java:1160) at com.igalia.wolvic.downloads.DownloadsManager.getDownloads(DownloadsManager.java:281) at com.igalia.wolvic.downloads.DownloadsManager.notifyDownloadsUpdate(DownloadsManager.java:313) at com.igalia.wolvic.downloads.DownloadsManager.$r8$lambda$0HiP7vssHY38l68BiKxs3V29Nug(Unknown Source:0) at com.igalia.wolvic.downloads.DownloadsManager$$ExternalSyntheticLambda0.run(D8$$SyntheticClass:0) at android.os.Handler.handleCallback(Handler.java:938) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loopOnce(Looper.java:214) at android.os.Looper.loop(Looper.java:304) at android.app.ActivityThread.main(ActivityThread.java:7918) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1010)
Removing a download involves on disk reading/writing operations. Those are blocking operations that should not happen in the main thread. Use the recently added disk executor to carry on the task. This fixes this report: D StrictMode policy violation; ~duration=102 ms: android.os.strictmode.DiskReadViolation at android.os.StrictMode$AndroidBlockGuardPolicy.onReadFromDisk(StrictMode.java:1659) at libcore.io.BlockGuardOs.access(BlockGuardOs.java:74) at libcore.io.ForwardingOs.access(ForwardingOs.java:131) at android.app.ActivityThread$AndroidOs.access(ActivityThread.java:7795) at java.io.UnixFileSystem.checkAccess(UnixFileSystem.java:281) at java.io.File.exists(File.java:813) at android.app.ContextImpl.ensurePrivateDirExists(ContextImpl.java:751) at android.app.ContextImpl.ensurePrivateDirExists(ContextImpl.java:742) at android.app.ContextImpl.getFilesDir(ContextImpl.java:787) at com.android.providers.downloads.Helpers.isFilenameValid(Helpers.java:665) at com.android.providers.downloads.Helpers.isFilenameValid(Helpers.java:527) at com.android.providers.downloads.DownloadProvider.delete(DownloadProvider.java:1629) at android.content.ContentProvider.delete(ContentProvider.java:1785) at android.content.ContentProvider$Transport.delete(ContentProvider.java:430) at android.content.ContentProviderNative.onTransact(ContentProviderNative.java:215) at android.os.Binder.execTransactInternal(Binder.java:1179) at android.os.Binder.execTransact(Binder.java:1143) at android.os.StrictMode.readAndHandleBinderCallViolations(StrictMode.java:2497) at android.os.Parcel.readExceptionCode(Parcel.java:2371) at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:139) at android.content.ContentProviderProxy.delete(ContentProviderNative.java:629) at android.content.ContentResolver.delete(ContentResolver.java:2333) at android.content.ContentResolver.delete(ContentResolver.java:2299) at android.app.DownloadManager.markRowDeleted(DownloadManager.java:1138) at android.app.DownloadManager.remove(DownloadManager.java:1150) at com.igalia.wolvic.downloads.DownloadsManager.removeDownload(DownloadsManager.java:250) at com.igalia.wolvic.utils.EnvironmentsManager$1.onUnzipFinish(EnvironmentsManager.java:193) at com.igalia.wolvic.utils.zip.UnzipResultReceiver.lambda$onReceiveResult$0(UnzipResultReceiver.java:59) at com.igalia.wolvic.utils.zip.UnzipResultReceiver$$ExternalSyntheticLambda0.accept(D8$$SyntheticClass:0) at java.util.ArrayList.forEach(ArrayList.java:1262) at com.igalia.wolvic.utils.zip.UnzipResultReceiver.onReceiveResult(UnzipResultReceiver.java:50) at android.os.ResultReceiver$MyRunnable.run(ResultReceiver.java:50) at android.os.Handler.handleCallback(Handler.java:938) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loopOnce(Looper.java:214) at android.os.Looper.loop(Looper.java:304) at android.app.ActivityThread.main(ActivityThread.java:7918) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1010)
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This PR fixes 2 strict mode policy violations in the downloads manager code
We should not perform blocking operations in the main thread. Use an executor do run them in a separate disk IO thread.
This PR sits on top of #1632 and #1635