Add tests verifying tx type using a lock contention scenario

Author: stancl

ext/pdo_sqlite/tests/pdo_sqlite_transaction_mode.phpt renamed to ext/pdo_sqlite/tests/subclasses/pdo_sqlite_transaction_mode.phpt

@@ -5,7 +5,9 @@ pdo_sqlite
 --FILE--
 <?php
 
-$pdo = PDO::connect('sqlite::memory:');
+$dsn = 'sqlite:file:foo?mode=memory&cache=shared';
+$pdo = PDO::connect($dsn);
+$pdo2 = PDO::connect($dsn);
 
 // Deferred by default before any transaction mode is set
 var_dump($pdo->getAttribute(PDO\Sqlite::ATTR_TRANSACTION_MODE) === PDO\Sqlite::ATTR_TRANSACTION_MODE_DEFERRED);
@@ -31,6 +33,39 @@ var_dump($pdo->setAttribute(PDO\Sqlite::ATTR_TRANSACTION_MODE, 123));
 var_dump($pdo->setAttribute(PDO\Sqlite::ATTR_TRANSACTION_MODE_DEFERRED, true));
 var_dump($pdo->setAttribute(PDO\Sqlite::ATTR_TRANSACTION_MODE_IMMEDIATE, true));
 var_dump($pdo->setAttribute(PDO\Sqlite::ATTR_TRANSACTION_MODE_EXCLUSIVE, true));
+
+// Set $pdo to deferred, try to get immediate transaction in $pdo2. There should be no lock contention
+$pdo->setAttribute(PDO\Sqlite::ATTR_TRANSACTION_MODE, PDO\Sqlite::ATTR_TRANSACTION_MODE_DEFERRED);
+$pdo->beginTransaction();
+try {
+    $pdo2->exec('begin immediate transaction');
+    $pdo2->rollBack();
+    printf("Database is not locked\n");
+} catch (PDOException $e) {
+    printf("Database is locked\n");
+}
+$pdo->rollBack();
+
+// Set $pdo to immediate, try to get immediate transaction in $pdo2. There SHOULD be lock contention
+$pdo->setAttribute(PDO\Sqlite::ATTR_TRANSACTION_MODE, PDO\Sqlite::ATTR_TRANSACTION_MODE_IMMEDIATE);
+$pdo->beginTransaction();
+try {
+    $pdo2->exec('begin immediate transaction');
+    printf("Database is not locked\n");
+} catch (PDOException $e) {
+    printf("Database is locked\n");
+}
+$pdo->rollBack();
+
+// Set $pdo to exclusive, try to get immediate transaction in $pdo2. There SHOULD be lock contention
+$pdo->setAttribute(PDO\Sqlite::ATTR_TRANSACTION_MODE, PDO\Sqlite::ATTR_TRANSACTION_MODE_EXCLUSIVE);
+$pdo->beginTransaction();
+try {
+    $pdo2->exec('begin immediate transaction');
+    printf("Database is not locked\n");
+} catch (PDOException $e) {
+    printf("Database is locked\n");
+}
 ?>
 --EXPECT--
 bool(true)
@@ -46,3 +81,6 @@ bool(false)
 bool(false)
 bool(false)
 bool(false)
+Database is not locked
+Database is locked
+Database is locked