containerd/content/local/locks.go
Stephen J Day 3e5e2ecc0a content/local: consistent handling of data and locks
The locks now retry on the backend side to prevent clients from having
to round trip on locks that might be momentarily held. This exposed some
timing errors in the updated_at fields for content ingest, so we've had
to move that to a separate file to export the monotonic go runtime
timestamps.

Signed-off-by: Stephen J Day <stephen.day@docker.com>
2017-11-16 16:13:19 -05:00

38 lines
571 B
Go

package local
import (
"sync"
"github.com/containerd/containerd/errdefs"
"github.com/pkg/errors"
)
// Handles locking references
var (
// locks lets us lock in process
locks = map[string]struct{}{}
locksMu sync.Mutex
)
func tryLock(ref string) error {
locksMu.Lock()
defer locksMu.Unlock()
if _, ok := locks[ref]; ok {
return errors.Wrapf(errdefs.ErrUnavailable, "ref %s locked", ref)
}
locks[ref] = struct{}{}
return nil
}
func unlock(ref string) {
locksMu.Lock()
defer locksMu.Unlock()
if _, ok := locks[ref]; ok {
delete(locks, ref)
}
}