Plan 9 Support about go-billy HOT 3 OPEN

I'll be sending a PR for Plan 9 support soon.

It's not really possible to implement Lock/Unlock using the "exclusive use" bit:

Per http://man.cat-v.org/plan_9/5/stat: “Exclusive use files may be open
for I/O by only one fid at a time across all clients of the server. If a
second open is attempted, it draws an error.”

Since Lock is called on an open file, if we can't open a locked file in the first place, we never even get into the Lock function to wait for the file to be unlocked by the other client. I think go-billy will need to use an API similar to the lockedfile package to support file locking on Plan 9.

I got all the tests passing on Plan 9, but I found that running go test ./... hangs in TestTempFileMany and TestTempFileManyWithUtil if we're using test cache. This is possibly a go tool bug. If I run the tests with go test -count 1 ./... everything passes.

from go-billy.

will be great if you can do a PR

from go-billy.

@henesy I think Lock is supposed to block until it acquires the lock (the posix implementation doesn't use LOCK_NB with flock). Maybe we can do something similar to the lockedfile package used by cmd/go.

Go's internal/filelock package does not support Plan 9.

from go-billy.