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PO"error code 5: database is locked" when using a ContentProvider
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copied!<p>I have an application that runs an activity with a service in a separate process that is started and bound to the activity. The service contains a handler that posts a runnable to be run after a delay.</p> <p>I want each component to log to the database, so I implemented a content provider that deals with database access and I call it from the service or activity via extended AsyncTask sub-classes.</p> <p>This all works beautifully on the emulator, but when I run it in debug on my phone I get a sporadic database locked error on my database writing: </p> <p><strong>UPDATE</strong></p> <p>I made some changes to my database handling and the error has changed slightly.</p> <pre><code>ERROR/Database(15235): Error inserting MY_MESSAGE ERROR/Database(15235): android.database.sqlite.SQLiteException: error code 5: database is locked ERROR/Database(15235): at android.database.sqlite.SQLiteStatement.native_execute(Native Method) ERROR/Database(15235): at android.database.sqlite.SQLiteStatement.execute(SQLiteStatement.java:61) ERROR/Database(15235): at android.database.sqlite.SQLiteDatabase.insertWithOnConflict(SQLiteDatabase.java:1591) ERROR/Database(15235): at android.database.sqlite.SQLiteDatabase.insert(SQLiteDatabase.java:1435) ERROR/Database(15235): at mypackagename.DatabaseHelper.insertLogging(DatabaseHelper.java:190) ERROR/Database(15235): at mypackagename.ContentProvider.insert(ContentProvider.java:139) ERROR/Database(15235): at android.content.ContentProvider$Transport.insert(ContentProvider.java:198) ERROR/Database(15235): at android.content.ContentResolver.insert(ContentResolver.java:604) ERROR/Database(15235): at mypackagename.Activity$LogToDatabase.doInBackground(Activity.java:642) ERROR/Database(15235): at mypackagename.Activity$LogToDatabase.doInBackground(Activity.java:1) ERROR/Database(15235): at android.os.AsyncTask$2.call(AsyncTask.java:185) ERROR/Database(15235): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306) ERROR/Database(15235): at java.util.concurrent.FutureTask.run(FutureTask.java:138) ERROR/Database(15235): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088) ERROR/Database(15235): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581) ERROR/Database(15235): at java.lang.Thread.run(Thread.java:1019) </code></pre> <p>I didn't put much detail before in because I thought it was an issue with different processes or threads, but now I'm thinking the problem is more likely located in the code calling the database. </p> <p>Questions:</p> <p>1) Why am I hitting locks when I'm using a ContentProvider?<br> 2) Why does this not show up on an equivalent API 2.3.3 emulator?<br> 3) Does the fact that none of my code catches an exception mean that the error was handled properly and I can ignore it?<br> 4) I read in another place someone suggesting adjusting the busy timeout. How would I do that? </p> <p>The irony that it's my debug logging that's causing the error is not lost on me.</p> <p>If I can't solve it, my next step is to bundle the logging messages up in a list and dump them out in batches of ten at a time.</p> <p>Here's the path the through the code to the error:</p> <p>Activity:</p> <pre><code>private void logDatabaseMessage(String status, String message) { String[] args = {status, message}; LogToDatabase logTask = new LogToDatabase(); logTask.execute(args); } private class LogToDatabase extends AsyncTask<String, Integer, Void> { @Override protected Void doInBackground(final String... args) { try { SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS"); String dateText = dateFormat.format(new Date()); ContentValues loggingValues = new ContentValues(); loggingValues.put(MyContentProvider.LOGGING_DATETIME, dateText); loggingValues.put(MyContentProvider.LOGGING_STATUS, args[0]); loggingValues.put(MyContentProvider.LOGGING_MESSAGE, args[1]); getContentResolver().insert(MyContentProvider.LOGGING_CONTENT_URI, loggingValues); } catch (Exception ex) { Log.e(TAG, "LogToDatabase.doInBackground threw exception: " + ex.getMessage()); ex.printStackTrace(); } return null; } } </code></pre> <p>ContentProvider:</p> <pre><code>@Override public Uri insert(Uri uri, ContentValues values) { Uri _uri = null; long rowID = 0; try { switch (uriMatcher.match(uri)) { case LOGGING: rowID = dbHelper.insertLogging(values); if (rowID == 0) throw new SQLException("Failed to insert row into " + uri); _uri = ContentUris.withAppendedId(LOGGING_CONTENT_URI, rowID); break; default: throw new SQLException("Failed to insert row into " + uri); } if (rowID != 0) getContext().getContentResolver().notifyChange(_uri, null); } catch (Exception ex) { Log.e(TAG, LogPrefix + "insert threw exception: " + ex.getMessage()); ex.printStackTrace(); } return _uri; } </code></pre> <p>DatabaseHelper:</p> <pre><code>public long insertLogging(ContentValues values) { long rowID = 0; try { rowID = db.insert(LOGGING_TABLE, null, values); } catch (Exception ex) { Log.e(TAG, LogPrefix + "ERROR: Failed to insert into logging table: " + ex.getMessage()); ex.printStackTrace(); } return rowID; } </code></pre>

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