mirror of https://github.com/minio/minio.git
64 lines
1.6 KiB
Go
64 lines
1.6 KiB
Go
// Copyright (c) 2022 MinIO, Inc.
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//
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// This file is part of MinIO Object Storage stack
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//
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// This program is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Affero General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Affero General Public License for more details.
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//
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// You should have received a copy of the GNU Affero General Public License
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// along with this program. If not, see <http://www.gnu.org/licenses/>.
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package jobtokens
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import (
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"errors"
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"sync"
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)
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// JobTokens provides a bounded semaphore with the ability to wait until all
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// concurrent jobs finish.
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type JobTokens struct {
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wg sync.WaitGroup
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tokens chan struct{}
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}
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// New creates a JobTokens object which allows up to n jobs to proceed
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// concurrently. n must be > 0.
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func New(n int) (*JobTokens, error) {
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if n <= 0 {
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return nil, errors.New("n must be > 0")
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}
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tokens := make(chan struct{}, n)
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for i := 0; i < n; i++ {
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tokens <- struct{}{}
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}
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return &JobTokens{
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tokens: tokens,
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}, nil
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}
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// Take is how a job (goroutine) can Take its turn.
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func (jt *JobTokens) Take() {
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jt.wg.Add(1)
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<-jt.tokens
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}
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// Give is how a job (goroutine) can give back its turn once done.
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func (jt *JobTokens) Give() {
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jt.wg.Done()
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jt.tokens <- struct{}{}
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}
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// Wait waits for all ongoing concurrent jobs to complete
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func (jt *JobTokens) Wait() {
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jt.wg.Wait()
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}
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