[THRIFT-1389] c_glib_generator.cc generates leaking code for cassandra_client_get_slice() and cassandra_client_get()

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.6.1
• Fix Version/s: 0.9.2
• Component/s: C glib - Compiler, C glib - Library

Environment

Used with Cassandra 0.8.4 on Linux 2.6.32 with x86_64

• Assignee: Simon South
• Reporter: Jerry Gally
• Created: 13/Oct/11 17:58
• Updated: 24/Sep/14 01:57
• Resolved: 24/Sep/14 01:57

Description

The generated cassandra.c cassandra_client_recv_get_slice() code for list processing instantiates an object of TYPE_COLUMN_OR_SUPER_COLUMN then calls thrift_struct_read() as in the following code snippet:

      switch (fid)
      {
        case 0:
          if (ftype == T_LIST)
          {
            {
              guint32 size;
              ThriftType element_type;
              if ((ret = thrift_protocol_read_list_begin (protocol, &element_type, &size, error)) < 0)
                return 0;
              xfer += ret;

              /* iterate through list elements */
              guint32 i;
              for (i = 0; i < size; i++)
              {
                ColumnOrSuperColumn * _elem19;
                _elem19 = g_object_new (TYPE_COLUMN_OR_SUPER_COLUMN, NULL);
                //printf("\nrecv_slice made %p\n", _elem19->column);
                if ((ret = thrift_struct_read (THRIFT_STRUCT (_elem19), protocol, error)) < 0)

When the object of TYPE_COLUMN_OR_SUPER_COLUMN is instantiated, it in turn instantiates a child of TYPE_COLUMN:

void
column_or_super_column_instance_init (ColumnOrSuperColumn * object)
{
  /* satisfy -Wall */
  THRIFT_UNUSED_VAR (object);
  object->column = g_object_new (TYPE_COLUMN, NULL);
  object->__isset_column = FALSE;

But this instance reference is lost and replaced by a new TYPE_COLUMN instantiation reference when the column member is read by column_or_super_column_read() within the same execution context of the top level cassandra_client_recv_get_slice() call:

    switch (fid)
    {
      case 1:
        if (ftype == T_STRUCT)
        {

          this_object->column = g_object_new (TYPE_COLUMN, NULL);
          if ((ret = thrift_struct_read (THRIFT_STRUCT (this_object->column), protocol, error)) < 0)

The above snippets/logic/leak described above for cassandra_client_get_slice() also apply for cassandra_client_get().