reduce locking when using SQLiteStatement (e25539fd) · Commits · e / os / android_frameworks_base

core/java/android/database/sqlite/SQLiteProgram.java

+97 −50

Original line number	Diff line number	Diff line
		@@ -17,6 +17,9 @@
		package android.database.sqlite;

		import android.util.Log;
		import android.util.Pair;

		import java.util.ArrayList;

		/**
		* A base class for compiled SQLite programs.
		@@ -29,7 +32,7 @@ public abstract class SQLiteProgram extends SQLiteClosable {
		private static final String TAG = "SQLiteProgram";

		/** the type of sql statement being processed by this object */
		private static final int SELECT_STMT = 1;
		/* package */ static final int SELECT_STMT = 1;
		private static final int UPDATE_STMT = 2;
		private static final int OTHER_STMT = 3;

		@@ -63,13 +66,40 @@ public abstract class SQLiteProgram extends SQLiteClosable {
		@Deprecated
		protected int nStatement = 0;

		/**
		* In the case of {@link SQLiteStatement}, this member stores the bindargs passed
		* to the following methods, instead of actually doing the binding.
		* <ul>
		* <li>{@link #bindBlob(int, byte[])}</li>
		* <li>{@link #bindDouble(int, double)}</li>
		* <li>{@link #bindLong(int, long)}</li>
		* <li>{@link #bindNull(int)}</li>
		* <li>{@link #bindString(int, String)}</li>
		* </ul>
		* <p>
		* Each entry in the array is a Pair of
		* <ol>
		* <li>bind arg position number</li>
		* <li>the value to be bound to the bindarg</li>
		* </ol>
		* <p>
		* It is lazily initialized in the above bind methods
		* and it is cleared in {@link #clearBindings()} method.
		* <p>
		* It is protected (in multi-threaded environment) by {@link SQLiteProgram}.this
		*/
		private ArrayList<Pair<Integer, Object>> bindArgs = null;

		/* package */ SQLiteProgram(SQLiteDatabase db, String sql) {
		this(db, sql, true);
		}

		/* package */ SQLiteProgram(SQLiteDatabase db, String sql, boolean compileFlag) {
		mSql = sql.trim();
		attachObjectToDatabase(db);
		db.acquireReference();
		db.addSQLiteClosable(this);
		mDatabase = db;
		nHandle = db.mNativeHandle;
		if (compileFlag) {
		compileSql();
		}
		@@ -120,7 +150,7 @@ public abstract class SQLiteProgram extends SQLiteClosable {
		nStatement = mCompiledSql.nStatement;
		}

		private int getSqlStatementType(String sql) {
		/* package */ int getSqlStatementType(String sql) {
		if (mSql.length() < 6) {
		return OTHER_STMT;
		}
		@@ -136,46 +166,11 @@ public abstract class SQLiteProgram extends SQLiteClosable {
		return OTHER_STMT;
		}

		private synchronized void attachObjectToDatabase(SQLiteDatabase db) {
		db.acquireReference();
		db.addSQLiteClosable(this);
		mDatabase = db;
		nHandle = db.mNativeHandle;
		}

		private synchronized void detachObjectFromDatabase() {
		mDatabase.removeSQLiteClosable(this);
		mDatabase.releaseReference();
		}

		/* package */ synchronized void verifyDbAndCompileSql() {
		mDatabase.verifyDbIsOpen();
		// use pooled database connection handles for SELECT SQL statements
		SQLiteDatabase db = (getSqlStatementType(mSql) != SELECT_STMT) ? mDatabase
		: mDatabase.getDbConnection(mSql);
		if (!db.equals(mDatabase)) {
		// the database connection handle to be used is not the same as the one supplied
		// in the constructor. do some housekeeping.
		detachObjectFromDatabase();
		attachObjectToDatabase(db);
		}
		// compile the sql statement
		if (nStatement > 0) {
		// already compiled.
		return;
		}
		mDatabase.lock();
		try {
		compileSql();
		} finally {
		mDatabase.unlock();
		}
		}

		@Override
		protected void onAllReferencesReleased() {
		releaseCompiledSqlIfNotInCache();
		detachObjectFromDatabase();
		mDatabase.removeSQLiteClosable(this);
		mDatabase.releaseReference();
		}

		@Override
		@@ -246,11 +241,17 @@ public abstract class SQLiteProgram extends SQLiteClosable {
		* @param index The 1-based index to the parameter to bind null to
		*/
		public void bindNull(int index) {
		mDatabase.verifyDbIsOpen();
		synchronized (this) {
		verifyDbAndCompileSql();
		acquireReference();
		try {
		if (this.nStatement == 0) {
		// since the SQL statement is not compiled, don't do the binding yet.
		// can be done before executing the SQL statement
		addToBindArgs(index, null);
		} else {
		native_bind_null(index);
		}
		} finally {
		releaseReference();
		}
		@@ -265,11 +266,15 @@ public abstract class SQLiteProgram extends SQLiteClosable {
		* @param value The value to bind
		*/
		public void bindLong(int index, long value) {
		mDatabase.verifyDbIsOpen();
		synchronized (this) {
		verifyDbAndCompileSql();
		acquireReference();
		try {
		if (this.nStatement == 0) {
		addToBindArgs(index, value);
		} else {
		native_bind_long(index, value);
		}
		} finally {
		releaseReference();
		}
		@@ -284,11 +289,15 @@ public abstract class SQLiteProgram extends SQLiteClosable {
		* @param value The value to bind
		*/
		public void bindDouble(int index, double value) {
		mDatabase.verifyDbIsOpen();
		synchronized (this) {
		verifyDbAndCompileSql();
		acquireReference();
		try {
		if (this.nStatement == 0) {
		addToBindArgs(index, value);
		} else {
		native_bind_double(index, value);
		}
		} finally {
		releaseReference();
		}
		@@ -306,11 +315,15 @@ public abstract class SQLiteProgram extends SQLiteClosable {
		if (value == null) {
		throw new IllegalArgumentException("the bind value at index " + index + " is null");
		}
		mDatabase.verifyDbIsOpen();
		synchronized (this) {
		verifyDbAndCompileSql();
		acquireReference();
		try {
		if (this.nStatement == 0) {
		addToBindArgs(index, value);
		} else {
		native_bind_string(index, value);
		}
		} finally {
		releaseReference();
		}
		@@ -328,11 +341,15 @@ public abstract class SQLiteProgram extends SQLiteClosable {
		if (value == null) {
		throw new IllegalArgumentException("the bind value at index " + index + " is null");
		}
		mDatabase.verifyDbIsOpen();
		synchronized (this) {
		verifyDbAndCompileSql();
		acquireReference();
		try {
		if (this.nStatement == 0) {
		addToBindArgs(index, value);
		} else {
		native_bind_blob(index, value);
		}
		} finally {
		releaseReference();
		}
		@@ -344,6 +361,7 @@ public abstract class SQLiteProgram extends SQLiteClosable {
		*/
		public void clearBindings() {
		synchronized (this) {
		bindArgs = null;
		if (this.nStatement == 0) {
		return;
		}
		@@ -362,6 +380,7 @@ public abstract class SQLiteProgram extends SQLiteClosable {
		*/
		public void close() {
		synchronized (this) {
		bindArgs = null;
		if (nHandle == 0 \|\| !mDatabase.isOpen()) {
		return;
		}
		@@ -369,6 +388,34 @@ public abstract class SQLiteProgram extends SQLiteClosable {
		}
		}

		private synchronized void addToBindArgs(int index, Object value) {
		if (bindArgs == null) {
		bindArgs = new ArrayList<Pair<Integer, Object>>();
		}
		bindArgs.add(new Pair<Integer, Object>(index, value));
		}

		/* package */ synchronized void compileAndbindAllArgs() {
		assert nStatement == 0;
		compileSql();
		if (bindArgs == null) {
		return;
		}
		for (Pair<Integer, Object> p : bindArgs) {
		if (p.second == null) {
		native_bind_null(p.first);
		} else if (p.second instanceof Long) {
		native_bind_long(p.first, (Long)p.second);
		} else if (p.second instanceof Double) {
		native_bind_double(p.first, (Double)p.second);
		} else if (p.second instanceof byte[]) {
		native_bind_blob(p.first, (byte[])p.second);
		} else {
		native_bind_string(p.first, (String)p.second);
		}
		}
		}

		/**
		* @deprecated This method is deprecated and must not be used.
		* Compiles SQL into a SQLite program.

core/java/android/database/sqlite/SQLiteStatement.java

+50 −28

Original line number	Diff line number	Diff line
		@@ -35,6 +35,8 @@ public class SQLiteStatement extends SQLiteProgram
		private static final boolean READ = true;
		private static final boolean WRITE = false;

		private SQLiteDatabase mOrigDb;

		/**
		* Don't use SQLiteStatement constructor directly, please use
		* {@link SQLiteDatabase#compileStatement(String)}
		@@ -53,6 +55,7 @@ public class SQLiteStatement extends SQLiteProgram
		* some reason
		*/
		public void execute() {
		synchronized(this) {
		long timeStart = acquireAndLock(WRITE);
		try {
		native_execute();
		@@ -61,6 +64,7 @@ public class SQLiteStatement extends SQLiteProgram
		releaseAndUnlock();
		}
		}
		}

		/**
		* Execute this SQL statement and return the ID of the row inserted due to this call.
		@@ -72,6 +76,7 @@ public class SQLiteStatement extends SQLiteProgram
		* some reason
		*/
		public long executeInsert() {
		synchronized(this) {
		long timeStart = acquireAndLock(WRITE);
		try {
		native_execute();
		@@ -81,6 +86,7 @@ public class SQLiteStatement extends SQLiteProgram
		releaseAndUnlock();
		}
		}
		}

		/**
		* Execute a statement that returns a 1 by 1 table with a numeric value.
		@@ -91,6 +97,7 @@ public class SQLiteStatement extends SQLiteProgram
		* @throws android.database.sqlite.SQLiteDoneException if the query returns zero rows
		*/
		public long simpleQueryForLong() {
		synchronized(this) {
		long timeStart = acquireAndLock(READ);
		try {
		long retValue = native_1x1_long();
		@@ -100,6 +107,7 @@ public class SQLiteStatement extends SQLiteProgram
		releaseAndUnlock();
		}
		}
		}

		/**
		* Execute a statement that returns a 1 by 1 table with a text value.
		@@ -110,6 +118,7 @@ public class SQLiteStatement extends SQLiteProgram
		* @throws android.database.sqlite.SQLiteDoneException if the query returns zero rows
		*/
		public String simpleQueryForString() {
		synchronized(this) {
		long timeStart = acquireAndLock(READ);
		try {
		String retValue = native_1x1_string();
		@@ -119,12 +128,14 @@ public class SQLiteStatement extends SQLiteProgram
		releaseAndUnlock();
		}
		}
		}

		/**
		* Called before every method in this class before executing a SQL statement,
		* this method does the following:
		* <ul>
		* <li>make sure the database is open</li>
		* <li>get a database connection from the connection pool,if possible</li>
		* <li>notifies {@link BlockGuard} of read/write</li>
		* <li>get lock on the database</li>
		* <li>acquire reference on this object</li>
		@@ -135,7 +146,14 @@ public class SQLiteStatement extends SQLiteProgram
		* methods in this class.
		*/
		private long acquireAndLock(boolean rwFlag) {
		verifyDbAndCompileSql();
		// use pooled database connection handles for SELECT SQL statements
		mDatabase.verifyDbIsOpen();
		SQLiteDatabase db = (getSqlStatementType(mSql) != SELECT_STMT) ? mDatabase
		: mDatabase.getDbConnection(mSql);
		// use the database connection obtained above
		mOrigDb = mDatabase;
		mDatabase = db;
		nHandle = mDatabase.mNativeHandle;
		if (rwFlag == WRITE) {
		BlockGuard.getThreadPolicy().onWriteToDisk();
		} else {
		@@ -145,6 +163,7 @@ public class SQLiteStatement extends SQLiteProgram
		mDatabase.lock();
		acquireReference();
		mDatabase.closePendingStatements();
		compileAndbindAllArgs();
		return startTime;
		}

		@@ -158,6 +177,9 @@ public class SQLiteStatement extends SQLiteProgram
		// release the compiled sql statement so that the caller's SQLiteStatement no longer
		// has a hard reference to a database object that may get deallocated at any point.
		releaseCompiledSqlIfNotInCache();
		// restore the database connection handle to the original value
		mDatabase = mOrigDb;
		nHandle = mDatabase.mNativeHandle;
		}

		private final native void native_execute();

core/tests/coretests/src/android/database/sqlite/SQLiteDatabaseTest.java

+53 −40

Original line number	Diff line number	Diff line
		@@ -279,11 +279,24 @@ public class SQLiteDatabaseTest extends AndroidTestCase {
		}
		}

		private static class ClassToTestSqlCompilationAndCaching extends SQLiteProgram {
		private ClassToTestSqlCompilationAndCaching(SQLiteDatabase db, String sql) {
		super(db, sql);
		}
		private static ClassToTestSqlCompilationAndCaching create(SQLiteDatabase db, String sql) {
		db.lock();
		try {
		return new ClassToTestSqlCompilationAndCaching(db, sql);
		} finally {
		db.unlock();
		}
		}
		}

		@SmallTest
		public void testLruCachingOfSqliteCompiledSqlObjs() {
		mDatabase.disableWriteAheadLogging();
		mDatabase.execSQL("CREATE TABLE test (i int, j int);");
		mDatabase.execSQL("insert into test values(1,1);");
		// set cache size
		int N = SQLiteDatabase.MAX_SQL_CACHE_SIZE;
		mDatabase.setMaxSqlCacheSize(N);
		@@ -292,22 +305,24 @@ public class SQLiteDatabaseTest extends AndroidTestCase {
		// insertion of (N+1)th entry, make sure 0th entry is closed
		ArrayList<Integer> stmtObjs = new ArrayList<Integer>();
		ArrayList<String> sqlStrings = new ArrayList<String>();
		SQLiteStatement stmt0 = null;
		int stmt0 = 0;
		for (int i = 0; i < N+1; i++) {
		String s = "select * from test where i = " + i + " and j = ?";
		String s = "insert into test values(" + i + ",?);";
		sqlStrings.add(s);
		SQLiteStatement c = mDatabase.compileStatement(s);
		c.bindLong(1, 1);
		stmtObjs.add(i, c.getSqlStatementId());
		ClassToTestSqlCompilationAndCaching c =
		ClassToTestSqlCompilationAndCaching.create(mDatabase, s);
		int n = c.getSqlStatementId();
		stmtObjs.add(i, n);
		if (i == 0) {
		// save thie SQLiteStatement obj. we want to make sure it is thrown out of
		// the cache and its handle is 0'ed.
		stmt0 = c;
		// save the statementId of this obj. we want to make sure it is thrown out of
		// the cache at the end of this test.
		stmt0 = n;
		}
		c.close();
		}
		// is 0'th entry out of the cache?
		assertEquals(0, stmt0.getSqlStatementId());
		// is 0'th entry out of the cache? it should be in the list of statementIds
		// corresponding to the pre-compiled sql statements to be finalized.
		assertTrue(mDatabase.getQueuedUpStmtList().contains(stmt0));
		for (int i = 1; i < N+1; i++) {
		SQLiteCompiledSql compSql = mDatabase.getCompiledStatementForSql(sqlStrings.get(i));
		assertNotNull(compSql);
		@@ -321,11 +336,7 @@ public class SQLiteDatabaseTest extends AndroidTestCase {
		"num1 INTEGER, num2 INTEGER, image BLOB);");
		final String statement = "DELETE FROM test WHERE _id=?;";
		SQLiteStatement statementDoNotClose = mDatabase.compileStatement(statement);
		// SQl statement is compiled only at find bind or execute call
		assertTrue(statementDoNotClose.getSqlStatementId() == 0);
		statementDoNotClose.bindLong(1, 1);
		assertTrue(statementDoNotClose.getSqlStatementId() > 0);
		int nStatement = statementDoNotClose.getSqlStatementId();
		/* do not close statementDoNotClose object.
		* That should leave it in SQLiteDatabase.mPrograms.
		* mDatabase.close() in tearDown() should release it.
		@@ -340,24 +351,25 @@ public class SQLiteDatabaseTest extends AndroidTestCase {
		public void testStatementClose() {
		mDatabase.execSQL("CREATE TABLE test (i int, j int);");
		// fill up statement cache in mDatabase\
		int N = 26;
		int N = SQLiteDatabase.MAX_SQL_CACHE_SIZE;
		mDatabase.setMaxSqlCacheSize(N);
		SQLiteStatement stmt;
		int stmt0Id = 0;
		for (int i = 0; i < N; i ++) {
		stmt = mDatabase.compileStatement("insert into test values(" + i + ", ?);");
		stmt.bindLong(1, 1);
		ClassToTestSqlCompilationAndCaching c =
		ClassToTestSqlCompilationAndCaching.create(mDatabase,
		"insert into test values(" + i + ", ?);");
		// keep track of 0th entry
		if (i == 0) {
		stmt0Id = stmt.getSqlStatementId();
		stmt0Id = c.getSqlStatementId();
		}
		stmt.executeInsert();
		stmt.close();
		c.close();
		}

		// add one more to the cache - and the above 'stmt0Id' should fall out of cache
		SQLiteStatement stmt1 = mDatabase.compileStatement("insert into test values(100, ?);");
		stmt1.bindLong(1, 1);
		ClassToTestSqlCompilationAndCaching stmt1 =
		ClassToTestSqlCompilationAndCaching.create(mDatabase,
		"insert into test values(100, ?);");
		stmt1.close();

		// the above close() should have queuedUp the statement for finalization
		@@ -381,18 +393,18 @@ public class SQLiteDatabaseTest extends AndroidTestCase {
		// fill up statement cache in mDatabase in a thread
		Thread t1 = new Thread() {
		@Override public void run() {
		int N = 26;
		int N = SQLiteDatabase.MAX_SQL_CACHE_SIZE;
		mDatabase.setMaxSqlCacheSize(N);
		SQLiteStatement stmt;
		for (int i = 0; i < N; i ++) {
		stmt = mDatabase.compileStatement("insert into test values(" + i + ", ?);");
		stmt.bindLong(1,1);
		ClassToTestSqlCompilationAndCaching c =
		ClassToTestSqlCompilationAndCaching.create(mDatabase,
		"insert into test values(" + i + ", ?);");
		// keep track of 0th entry
		if (i == 0) {
		setStmt0Id(stmt.getSqlStatementId());
		stmt0Id = c.getSqlStatementId();
		}
		stmt.executeInsert();
		stmt.close();
		c.close();
		}
		}
		};
		@@ -404,9 +416,9 @@ public class SQLiteDatabaseTest extends AndroidTestCase {
		// just for the heck of it, do it in a separate thread
		Thread t2 = new Thread() {
		@Override public void run() {
		SQLiteStatement stmt1 = mDatabase.compileStatement(
		ClassToTestSqlCompilationAndCaching stmt1 =
		ClassToTestSqlCompilationAndCaching.create(mDatabase,
		"insert into test values(100, ?);");
		stmt1.bindLong(1, 1);
		stmt1.close();
		}
		};
		@@ -452,18 +464,18 @@ public class SQLiteDatabaseTest extends AndroidTestCase {
		// fill up statement cache in mDatabase in a thread
		Thread t1 = new Thread() {
		@Override public void run() {
		int N = 26;
		int N = SQLiteDatabase.MAX_SQL_CACHE_SIZE;
		mDatabase.setMaxSqlCacheSize(N);
		SQLiteStatement stmt;
		for (int i = 0; i < N; i ++) {
		stmt = mDatabase.compileStatement("insert into test values(" + i + ", ?);");
		stmt.bindLong(1, 1);
		ClassToTestSqlCompilationAndCaching c =
		ClassToTestSqlCompilationAndCaching.create(mDatabase,
		"insert into test values(" + i + ", ?);");
		// keep track of 0th entry
		if (i == 0) {
		setStmt0Id(stmt.getSqlStatementId());
		stmt0Id = c.getSqlStatementId();
		}
		stmt.executeInsert();
		stmt.close();
		c.close();
		}
		}
		};
		@@ -475,7 +487,8 @@ public class SQLiteDatabaseTest extends AndroidTestCase {
		// just for the heck of it, do it in a separate thread
		Thread t2 = new Thread() {
		@Override public void run() {
		SQLiteStatement stmt1 = mDatabase.compileStatement(
		ClassToTestSqlCompilationAndCaching stmt1 =
		ClassToTestSqlCompilationAndCaching.create(mDatabase,
		"insert into test values(100, ?);");
		stmt1.bindLong(1, 1);
		stmt1.close();

core/tests/coretests/src/android/database/sqlite/SQLiteStatementTest.java

+16 −86

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