The counter value needs to be aligned to 64 bit in memory for the
atomic functions to work on some platform (such as 32 bit ARM).
The atomic package says in its documentation:
> These functions require great care to be used correctly. Except for
> special, low-level applications, synchronization is better done with
> channels or the facilities of the sync package.
This commit replaces the atomic functions with a simple sync.Mutex, so
we don't have to care about alignment.
The canUpdateStatus check was simplified in #2608, but it accidentally flipped
the condition. The correct check is as follows: If the output is a pipe then
restic probably runs in mintty/cygwin. In that case it's possible to
update the output status. In all other cases it isn't.
This commit inverts to condition again to offer the previous and correct
behavior.
On shutdown the backup commands waits for the terminal output goroutine
to stop. However while running in the background the goroutine ignored
the canceled context.
When the backup is interrupted for some reason while the scanner is
still active this could lead to a deadlock. Interruptions are triggered
by canceling the context object used by both the backup progress UI and
the scanner. It is possible that a context is canceled between the
respective check in the scanner and it calling the `ReportTotal` method
of the UI. The latter method sends a message to the UI goroutine.
However, a canceled context will also stop that goroutine, which can
cause the channel send operation to block indefinitely.
This is resolved by adding a `closed` channel which is closed once the
UI goroutine is stopped and serves as an escape hatch for reported UI
updates.
This change covers not just the ReportTotal method but all potentially
affected methods of the progress UI implementation.
The previous implementation was repeating the implementation that is
found inside of io.WriteString. Simplify by making use of the stdlib's
implementation.
internal/ui/jsonstatus and termstatus sound similar but are not related
in any way. Instead `internal/ui/backup` and `internal/ui/jsonstatus/status`
are the counterparts. Rename the latter to `internal/ui/json/backup` to
make this clear.
jsonstatus wrote the JSON output without synchronization to the
stdio_wrapper which caused mangling between different status lines.
Use the Print and Error methods of termstatus instead which use a
central goroutine to synchronize output.
When restic reads the backup from stdin, the number of bytes processed
was always displayed as zero. The reason is that the UI for the archive
uses the total bytes as returned by the scanner, which is zero for
stdin. So instead we keep track of the real number of bytes processed
and print that at the end.
Closes#2136
Alexander Neumann