Add support for transaction multiplexing

Also delay getting a connection until after we do all the sanity
checks (e.g., that there is no active transaction). Otherwise we
are running risk of getting blocked rather than throwing an
exception.

1 files changed, 5 insertions, 4 deletions

diff --git a/odb/pgsql/transaction-impl.hxx b/odb/pgsql/transaction-impl.hxx
index d3a76ce..2551994 100644
--- a/odb/pgsql/transaction-impl.hxx
+++ b/odb/pgsql/transaction-impl.hxx
@@ -23,19 +23,20 @@ namespace odb
   {
     class LIBODB_PGSQL_EXPORT transaction_impl: public odb::transaction_impl
     {
-    protected:
-      friend class connection;
-      friend class transaction;
-
+    public:
       typedef pgsql::database database_type;
       typedef pgsql::connection connection_type;
 
+      transaction_impl (database_type&);
       transaction_impl (connection_ptr);
 
       virtual
       ~transaction_impl ();
 
       virtual void
+      start ();
+
+      virtual void
       commit ();
 
       virtual void