Currently start() is not prepared to handle exceptions thrown from
service initialization. It's easy to trigger such exceprion by
starting two tests at the same time, which will result in socket bind
error.
Exception thrown from start() typically results in assertion failures
like this one:
seastar::sharded<Service>::~sharded() [with Service = database]: Assertion `_instances.empty()' failed.
This patch fixes the problem by combining start() and stop() in a
single do_with() and using RAII for stopping services.
Now exceptions thrown from service initialization should stop services
in proper order and let the original exception to pass
through. Example result:
fatal error in "test_new_schema_with_no_structural_change_is_propagated": std::runtime_error: bind: Address already in use
Message-Id: <1458768018-27662-1-git-send-email-tgrabiec@scylladb.com>
We use boost::any to convert to and from database values (stored in
serlialized form) and native C++ values. boost::any captures information
about the data type (how to copy/move/delete etc.) and stores it inside
the boost::any instance. We later retrieve the real value using
boost::any_cast.
However, data_value (which has a boost::any member) already has type
information as a data_type instance. By teaching data_type intances about
the corresponding native type, we can elimiante the use of boost::any.
While boost::any is evil and eliminating it improves efficiency somewhat,
the real goal is growing native type support in data_type. We will use that
later to store native types in the cache, enabling O(log n) access to
collections, O(1) access to tuples, and more efficient large blob support.
