transactions should always start with the last revision and release it when done

src/runtime/c/pgf/namespace.h

@@ -260,7 +260,7 @@ public:
             return node->right;
         } else {
             ref<Node> left = pop_first(node->left, res);
-            ref<Node> node = upd_node(node, left, node->right);
+            node = upd_node(node, left, node->right);
             return balanceR(node);
         }
     }
@@ -275,7 +275,7 @@ public:
             return node->left;
         } else {
             ref<Node> right = pop_last(node->right, res);
-            ref<Node> node  = upd_node(node, node->left, right);
+            node = upd_node(node, node->left, right);
             return balanceL(node);
         }
     }

src/runtime/c/pgf/pgf.cxx

@@ -1057,13 +1057,12 @@ void pgf_check_type(PgfDB *db, PgfRevision revision,
 }
 
 PGF_API
-PgfRevision pgf_start_transaction(PgfDB *db, PgfRevision revision,
+PgfRevision pgf_start_transaction(PgfDB *db, PgfExn *err)
-                                  PgfExn *err)
 {
     PGF_API_BEGIN {
         DB_scope scope(db, WRITER_SCOPE);
 
-        ref<PgfPGF> pgf = db->revision2pgf(revision);
+        ref<PgfPGF> pgf = db->get_active_revision();
 
         db->start_transaction();
 
@@ -1079,6 +1078,8 @@ PgfRevision pgf_start_transaction(PgfDB *db, PgfRevision revision,
 
         object rev = db->register_revision(new_pgf.tagged(), PgfDB::get_txn_id());
 
+        PgfDB::free(pgf);
+
         db->ref_count++;
         return rev;
     } PGF_API_END

src/runtime/c/pgf/pgf.h

@@ -462,8 +462,7 @@ void pgf_check_type(PgfDB *db, PgfRevision revision,
                     PgfExn *err);
 
 PGF_API_DECL
-PgfRevision pgf_start_transaction(PgfDB *db, PgfRevision revision,
+PgfRevision pgf_start_transaction(PgfDB *db, PgfExn *err);
-                                  PgfExn *err);
 
 PGF_API_DECL
 void pgf_commit_transaction(PgfDB *db, PgfRevision revision,

src/runtime/haskell/PGF2/FFI.hsc

@@ -175,7 +175,7 @@ foreign import ccall pgf_infer_expr :: Ptr PgfDB -> Ptr PGF -> Ptr (StablePtr Ex
 
 foreign import ccall pgf_check_type :: Ptr PgfDB -> Ptr PGF -> Ptr (StablePtr Type) -> Ptr PgfMarshaller -> Ptr PgfUnmarshaller -> Ptr PgfExn -> IO ()
 
-foreign import ccall pgf_start_transaction :: Ptr PgfDB -> Ptr PGF -> Ptr PgfExn -> IO (Ptr PGF)
+foreign import ccall pgf_start_transaction :: Ptr PgfDB -> Ptr PgfExn -> IO (Ptr PGF)
 
 foreign import ccall pgf_commit_transaction :: Ptr PgfDB -> Ptr PGF -> Ptr PgfExn -> IO ()
 

src/runtime/haskell/PGF2/Transactions.hsc

@@ -84,7 +84,7 @@ modifyPGF p (Transaction f) =
   withForeignPtr (a_revision p) $ \c_revision ->
   withPgfExn "modifyPGF" $ \c_exn ->
   mask $ \restore -> do
-    c_revision <- pgf_start_transaction (a_db p) c_revision c_exn
+    c_revision <- pgf_start_transaction (a_db p) c_exn
     ex_type <- (#peek PgfExn, type) c_exn
     if (ex_type :: (#type PgfExnType)) == (#const PGF_EXN_NONE)
       then do ((restore (f (a_db p) c_revision c_revision c_exn))

src/runtime/haskell/tests/transactions.hs

@@ -9,10 +9,8 @@ main = do
   gr1 <- readPGF "tests/basic.pgf"
   let Just ty = readType "(N -> N) -> P (s z)"
 
-  print 1
   gr2 <- modifyPGF gr1 (createFunction "foo" ty 0 [] pi >>
                         createCategory "Q" [(Explicit,"x",ty)] pi)
-  print 2
 
   gr4 <- checkoutPGF gr1
 
@@ -21,6 +19,7 @@ main = do
   gr7 <- modifyPGF gr1 $
            createConcrete "basic_eng" $ do
              setConcreteFlag "test_flag" (LStr "test")
+
   let Just cnc = Map.lookup "basic_eng" (languages gr7)
 
   c <- runTestTT $
@@ -31,8 +30,8 @@ main = do
       ,TestCase (assertEqual "original categories" ["Float","Int","N","P","S","String"] (categories gr1))
       ,TestCase (assertEqual "extended categories" ["Float","Int","N","P","Q","S","String"] (categories gr2))
       ,TestCase (assertEqual "Q context" (Just [(Explicit,"x",ty)]) (categoryContext gr2 "Q"))
-      ,TestCase (assertEqual "reduced functions" ["c","floatLit","intLit","nat","s","stringLit","z"] (functions gr6))
+      ,TestCase (assertEqual "reduced functions" ["c","floatLit","foo","intLit","nat","s","stringLit","z"] (functions gr6))
-      ,TestCase (assertEqual "reduced categories" ["Float","Int","N","P","String"] (categories gr6))
+      ,TestCase (assertEqual "reduced categories" ["Float","Int","N","P","Q","String"] (categories gr6))
       ,TestCase (assertEqual "old function type" Nothing   (functionType gr1 "foo"))
       ,TestCase (assertEqual "new function type" (Just ty) (functionType gr2 "foo"))
       ,TestCase (assertEqual "old function prob" (-log 0)  (functionProbability gr1 "foo"))
@@ -49,3 +48,4 @@ main = do
   if (errors c == 0) && (failures c == 0)
     then exitSuccess
     else exitFailure
+

src/runtime/javascript/ffi.ts

@@ -129,7 +129,7 @@ export const runtime = ffi.Library('libpgf', {
   pgf_print_context: [PgfTextPtr, [size_t, PgfTypeHypoPtr, PgfPrintContextPtr, ref.types.int, PgfMarshallerPtr]],
   pgf_read_type: [PgfType, [PgfTextPtr, PgfUnmarshallerPtr]],
 
-  pgf_start_transaction: [PgfRevision, [PgfDBPtr, PgfRevision, PgfExnPtr]],
+  pgf_start_transaction: [PgfRevision, [PgfDBPtr, PgfExnPtr]],
   pgf_commit_transaction: [ref.types.void, [PgfDBPtr, PgfRevision, PgfExnPtr]],
   pgf_rollback_transaction: [ref.types.void, [PgfDBPtr, PgfRevision]],
   pgf_checkout_revision: [PgfRevision, [PgfDBPtr, PgfExnPtr]],

src/runtime/python/transactions.c

@@ -40,7 +40,7 @@ PGF_newTransaction(PGFObject *self, PyObject *args)
         return NULL;
 
     PgfExn err;
-    PgfRevision rev = pgf_start_transaction(self->db, self->revision, &err);
+    PgfRevision rev = pgf_start_transaction(self->db, &err);
     if (handleError(err) != PGF_EXN_NONE) {
         return NULL;
     }