google.golang.org/grpc@v1.62.1/internal/grpcsync/oncefunc.go (about)

     1  /*
     2   *
     3   * Copyright 2022 gRPC authors.
     4   *
     5   * Licensed under the Apache License, Version 2.0 (the "License");
     6   * you may not use this file except in compliance with the License.
     7   * You may obtain a copy of the License at
     8   *
     9   *     http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   *
    17   */
    18  
    19  package grpcsync
    20  
    21  import (
    22  	"sync"
    23  )
    24  
    25  // OnceFunc returns a function wrapping f which ensures f is only executed
    26  // once even if the returned function is executed multiple times.
    27  func OnceFunc(f func()) func() {
    28  	var once sync.Once
    29  	return func() {
    30  		once.Do(f)
    31  	}
    32  }