Oilpan: Prepare to move SQLTransactionBackendSync and SQLTransactionSync to Oilpan heap.

Source/modules/webdatabase/SQLTransactionBackendSync.cpp

Index: Source/modules/webdatabase/SQLTransactionBackendSync.cpp
diff --git a/Source/modules/webdatabase/SQLTransactionBackendSync.cpp b/Source/modules/webdatabase/SQLTransactionBackendSync.cpp
index b1e298be8ddb8194391ae1e64617d2c66d9ec234..ffe0f4038e160e543a8d35bee1b27a667405b100 100644
--- a/Source/modules/webdatabase/SQLTransactionBackendSync.cpp
+++ b/Source/modules/webdatabase/SQLTransactionBackendSync.cpp
@@ -62,13 +62,27 @@ SQLTransactionBackendSync::SQLTransactionBackendSync(DatabaseSync* db, PassOwnPt
     ASSERT(m_database->executionContext()->isContextThread());
 }
 
-SQLTransactionBackendSync::~SQLTransactionBackendSync()
+void SQLTransactionBackendSync::rollbackIfInProgress()
 {
-    ASSERT(m_database->executionContext()->isContextThread());
+    ASSERT(!m_database->executionContext() || m_database->executionContext()->isContextThread());
     if (m_sqliteTransaction && m_sqliteTransaction->inProgress())
         rollback();
 }
 
+SQLTransactionBackendSync::~SQLTransactionBackendSync()
+{
+#if ENABLE(OILPAN)
+    ASSERT(!m_sqliteTransaction || !m_sqliteTransaction->inProgress());
+#else
+    rollbackIfInProgress();
+#endif
+}
+
+void SQLTransactionBackendSync::trace(Visitor* visitor)
+{
+    visitor->trace(m_database);
+}
+
 PassRefPtr<SQLResultSet> SQLTransactionBackendSync::executeSQL(const String& sqlStatement, const Vector<SQLValue>& arguments, ExceptionState& exceptionState)
 {
     ASSERT(m_database->executionContext()->isContextThread());
@@ -229,9 +243,10 @@ void SQLTransactionBackendSync::commit(ExceptionState& exceptionState)
     m_database->reportCommitTransactionResult(0, -1, 0); // OK
 }
 
+// This can be called during GC. Do not allocate new on-heap objects.

[Vyacheslav Egorov (Google), 2014/03/18 07:54:55]

I don't think comments like this scale as long you call more than one function
inside because they should also essentially have the same comment.

Sadly I don't see any good way to handle this.

We can consider annotating functions that can be called during GC with a special
attribute and checking their bodies transitively but that would soon turn into a
mess probably.

 void SQLTransactionBackendSync::rollback()
 {
-    ASSERT(m_database->executionContext()->isContextThread());
+    ASSERT(!m_database->executionContext() || m_database->executionContext()->isContextThread());
     m_database->disableAuthorizer();
     if (m_sqliteTransaction) {

[Vyacheslav Egorov (Google), 2014/03/18 07:54:55]

from my reading of the code this whole if can be just replaced with
m_sqliteTransaction.clear() because destructor does rollback.

SQLiteTransaction::~SQLiteTransaction()
{
    if (m_inProgress)
        rollback();
}

         m_sqliteTransaction->rollback();