/
guarded.go
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/
guarded.go
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// Licensed to the Apache Software Foundation (ASF) under one or more
// contributor license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright ownership.
// The ASF licenses this file to You under the Apache License, Version 2.0
// (the "License"); you may not use this file except in compliance with
// the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package errorx contains utilities for handling errors.
package errorx
import "sync"
// GuardedError is a concurrency-safe error wrapper. It is sticky
// in that the first error won't be overwritten.
type GuardedError struct {
err error
mu sync.Mutex
}
// Error returns the guarded error.
func (g *GuardedError) Error() error {
g.mu.Lock()
defer g.mu.Unlock()
return g.err
}
// TrySetError sets the error, if not already set. Returns true iff the
// error was set.
func (g *GuardedError) TrySetError(err error) bool {
g.mu.Lock()
defer g.mu.Unlock()
upd := (g.err == nil)
if upd {
g.err = err
}
return upd
}