Clang dislikes forward-declared functions returning auto, so declare the
type up front. Functions returning auto are a readability problem
anyway.
To solve a circular dependency problem (get_local_injector() ->
error_injection<> -> get_local_injector()), which is further compounded
by problems in using template specializations before they are defined
(which is forbidden), the storage for get_local_injector() was moved
to error_injection<>, and get_local_injector() is just an accessor.
After this, error_injection<> does not depend on get_local_injector().
Error injection class is implemented in order to allow injecting
various errors (exceptions, stalls, etc.) in code for testing
purposes.
Error injection is enabled via compile flag
SCYLLA_ENABLE_ERROR_INJECTION
TODO: manage shard instances
Enable error injection in debug/dev/sanitize modes.
Unit tests for error injection class.
Closes#3295
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Signed-off-by: Alejo Sanchez <alejo.sanchez@scylladb.com>
