/
manager.go
60 lines (52 loc) · 1.36 KB
/
manager.go
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// Copyright 2018 Istio Authors
//
// Licensed 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 reserveport
import (
"fmt"
"sync"
)
type managerImpl struct {
pool []ReservedPort
index int
mutex sync.Mutex
}
func (m *managerImpl) ReservePort() (ReservedPort, error) {
m.mutex.Lock()
defer m.mutex.Unlock()
if m.index >= len(m.pool) {
// Re-create the pool.
var err error
m.pool, err = allocatePool(poolSize)
if err != nil {
return nil, err
}
m.index = 0
// Don't need to free the pool, since all ports have been reserved.
}
p := m.pool[m.index]
if p == nil {
return nil, fmt.Errorf("attempting to reserve port after manager closed")
}
m.pool[m.index] = nil
m.index++
return p, nil
}
func (m *managerImpl) Close() (err error) {
m.mutex.Lock()
defer m.mutex.Unlock()
pool := m.pool
m.pool = nil
m.index = 0
return freePool(pool)
}