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Merge "reduce synchronization on SQLiteDatabase wherever possible"

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This commit is contained in:
Vasu Nori
2010-09-27 14:15:08 -07:00
committed by Android (Google) Code Review
parent 726e75d4d1 8fef1b7520
commit 2953283fbd
1 changed files with 82 additions and 93 deletions
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175
core/java/android/database/sqlite/DatabaseConnectionPool.java
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@@ -58,16 +58,14 @@ import java.util.Random;
/**
* close all database connections in the pool - even if they are in use!
*/
/* package */ void close() {
synchronized(mParentDbObj) {
if (Log.isLoggable(TAG, Log.DEBUG)) {
Log.d(TAG, "Closing the connection pool on " + mParentDbObj.getPath() + toString());
}
for (int i = mPool.size() - 1; i >= 0; i--) {
mPool.get(i).mDb.close();
}
mPool.clear();
/* package */ synchronized void close() {
if (Log.isLoggable(TAG, Log.DEBUG)) {
Log.d(TAG, "Closing the connection pool on " + mParentDbObj.getPath() + toString());
}
for (int i = mPool.size() - 1; i >= 0; i--) {
mPool.get(i).mDb.close();
}
mPool.clear();
}
/**
@@ -77,76 +75,73 @@ import java.util.Random;
* the compiled statement for this sql.
* @return the Database connection that the caller can use
*/
/* package */ SQLiteDatabase get(String sql) {
/* package */ synchronized SQLiteDatabase get(String sql) {
SQLiteDatabase db = null;
PoolObj poolObj = null;
synchronized(mParentDbObj) {
int poolSize = mPool.size();
if (Log.isLoggable(TAG, Log.DEBUG)) {
assert sql != null;
doAsserts();
}
if (getFreePoolSize() == 0) {
// no free ( = available) connections
if (mMaxPoolSize == poolSize) {
// maxed out. can't open any more connections.
// let the caller wait on one of the pooled connections
// preferably a connection caching the pre-compiled statement of the given SQL
if (mMaxPoolSize == 1) {
poolObj = mPool.get(0);
} else {
for (int i = 0; i < mMaxPoolSize; i++) {
if (mPool.get(i).mDb.isSqlInStatementCache(sql)) {
poolObj = mPool.get(i);
break;
}
}
if (poolObj == null) {
// there are no database connections with the given SQL pre-compiled.
// ok to return any of the connections.
if (rand == null) {
rand = new Random(SystemClock.elapsedRealtime());
}
poolObj = mPool.get(rand.nextInt(mMaxPoolSize));
}
}
db = poolObj.mDb;
} else {
// create a new connection and add it to the pool, since we haven't reached
// max pool size allowed
db = mParentDbObj.createPoolConnection((short)(poolSize + 1));
poolObj = new PoolObj(db);
mPool.add(poolSize, poolObj);
}
} else {
// there are free connections available. pick one
int poolSize = mPool.size();
if (Log.isLoggable(TAG, Log.DEBUG)) {
assert sql != null;
doAsserts();
}
if (getFreePoolSize() == 0) {
// no free ( = available) connections
if (mMaxPoolSize == poolSize) {
// maxed out. can't open any more connections.
// let the caller wait on one of the pooled connections
// preferably a connection caching the pre-compiled statement of the given SQL
for (int i = 0; i < poolSize; i++) {
if (mPool.get(i).isFree() && mPool.get(i).mDb.isSqlInStatementCache(sql)) {
poolObj = mPool.get(i);
break;
}
}
if (poolObj == null) {
// didn't find a free database connection with the given SQL already
// pre-compiled. return a free connection (this means, the same SQL could be
// pre-compiled on more than one database connection. potential wasted memory.)
for (int i = 0; i < poolSize; i++) {
if (mPool.get(i).isFree()) {
if (mMaxPoolSize == 1) {
poolObj = mPool.get(0);
} else {
for (int i = 0; i < mMaxPoolSize; i++) {
if (mPool.get(i).mDb.isSqlInStatementCache(sql)) {
poolObj = mPool.get(i);
break;
}
}
if (poolObj == null) {
// there are no database connections with the given SQL pre-compiled.
// ok to return any of the connections.
if (rand == null) {
rand = new Random(SystemClock.elapsedRealtime());
}
poolObj = mPool.get(rand.nextInt(mMaxPoolSize));
}
}
db = poolObj.mDb;
} else {
// create a new connection and add it to the pool, since we haven't reached
// max pool size allowed
db = mParentDbObj.createPoolConnection((short)(poolSize + 1));
poolObj = new PoolObj(db);
mPool.add(poolSize, poolObj);
}
assert poolObj != null;
assert poolObj.mDb == db;
poolObj.acquire();
} else {
// there are free connections available. pick one
// preferably a connection caching the pre-compiled statement of the given SQL
for (int i = 0; i < poolSize; i++) {
if (mPool.get(i).isFree() && mPool.get(i).mDb.isSqlInStatementCache(sql)) {
poolObj = mPool.get(i);
break;
}
}
if (poolObj == null) {
// didn't find a free database connection with the given SQL already
// pre-compiled. return a free connection (this means, the same SQL could be
// pre-compiled on more than one database connection. potential wasted memory.)
for (int i = 0; i < poolSize; i++) {
if (mPool.get(i).isFree()) {
poolObj = mPool.get(i);
break;
}
}
}
db = poolObj.mDb;
}
assert poolObj != null;
assert poolObj.mDb == db;
poolObj.acquire();
if (Log.isLoggable(TAG, Log.DEBUG)) {
Log.d(TAG, "END get-connection: " + toString() + poolObj.toString());
}
@@ -159,29 +154,25 @@ import java.util.Random;
* release the given database connection back to the pool.
* @param db the connection to be released
*/
/* package */ void release(SQLiteDatabase db) {
PoolObj poolObj;
synchronized(mParentDbObj) {
if (Log.isLoggable(TAG, Log.DEBUG)) {
assert db.mConnectionNum > 0;
doAsserts();
assert mPool.get(db.mConnectionNum - 1).mDb == db;
}
poolObj = mPool.get(db.mConnectionNum - 1);
if (Log.isLoggable(TAG, Log.DEBUG)) {
Log.d(TAG, "BEGIN release-conn: " + toString() + poolObj.toString());
}
if (poolObj.isFree()) {
throw new IllegalStateException("Releasing object already freed: " +
db.mConnectionNum);
}
poolObj.release();
/* package */ synchronized void release(SQLiteDatabase db) {
if (Log.isLoggable(TAG, Log.DEBUG)) {
assert db.mConnectionNum > 0;
doAsserts();
assert mPool.get(db.mConnectionNum - 1).mDb == db;
}
PoolObj poolObj = mPool.get(db.mConnectionNum - 1);
if (Log.isLoggable(TAG, Log.DEBUG)) {
Log.d(TAG, "BEGIN release-conn: " + toString() + poolObj.toString());
}
if (poolObj.isFree()) {
throw new IllegalStateException("Releasing object already freed: " +
db.mConnectionNum);
}
poolObj.release();
if (Log.isLoggable(TAG, Log.DEBUG)) {
Log.d(TAG, "END release-conn: " + toString() + poolObj.toString());
}
@@ -191,12 +182,10 @@ import java.util.Random;
* Returns a list of all database connections in the pool (both free and busy connections).
* This method is used when "adb bugreport" is done.
*/
/* package */ ArrayList<SQLiteDatabase> getConnectionList() {
/* package */ synchronized ArrayList<SQLiteDatabase> getConnectionList() {
ArrayList<SQLiteDatabase> list = new ArrayList<SQLiteDatabase>();
synchronized(mParentDbObj) {
for (int i = mPool.size() - 1; i >= 0; i--) {
list.add(mPool.get(i).mDb);
}
for (int i = mPool.size() - 1; i >= 0; i--) {
list.add(mPool.get(i).mDb);
}
return list;
}