Currently there are two possible situations related to low balance on
the account which is used for bridge operations:
1. The account which is used to sign transactions to be addressed by
ForeignBridge contract has low balance. So, the bridge is not able to do
deposit_relay and withdraw_confirm.
2. The account which is used to sign transactions to be addressed by
HomeBridge contract has low balance. So, the bridge is not able to do
withdraw_relay.
In both cases bridges hangs silently at the moment of sending
transactions and does not proceed with further actions even the
operation is intended to be performed in opposite direction (e.g. the
bridge hangs at the moment to perform withdraw_relay, so deposit_relay
cannot be performed either).
Solution: make bridge track its balance and hande insufficient
Bridge will crash with ERR_INSUFFICIENT_FUNDS (code 4) so that
supervisor can decide what should happen next. It will also log the
condition.
P.S.Make sure to run the tests with `--test-threads=1` to avoid
other test conflicting with this one. A better solution to this
issue must be devised later, however.
It is impossible to tell whether the bridge
is being shut down intentionally or because of
an error. This is particularly important
for supervising the process, both in development
and production.
Solution: handle SIGINT and SIGTERM as a special case
and designate a separate status code (3) for intentional
shutdowns.
Also, include an example supervisor for development
mode (examples/suprevisor). Simply prepend it before
the invocation of bridge to supervise it.
Yurii Rashkovskii
debris