46 lines
955 B
Go
46 lines
955 B
Go
// Copyright (C) 2019 Storj Labs, Inc.
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// See LICENSE for copying information
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package sync2
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import (
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"context"
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"golang.org/x/sync/semaphore"
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)
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// Semaphore implements a closable semaphore
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type Semaphore struct {
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ctx context.Context
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close func()
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sema *semaphore.Weighted
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}
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// NewSemaphore creates a semaphore with the specified size.
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func NewSemaphore(size int) *Semaphore {
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sema := &Semaphore{}
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sema.Init(size)
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return sema
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}
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// Init initializes semaphore to the specified size.
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func (sema *Semaphore) Init(size int) {
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sema.ctx, sema.close = context.WithCancel(context.Background())
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sema.sema = semaphore.NewWeighted(int64(size))
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}
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// Close closes the semaphore from further use.
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func (sema *Semaphore) Close() {
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sema.close()
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}
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// Lock locks the semaphore.
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func (sema *Semaphore) Lock() bool {
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return sema.sema.Acquire(sema.ctx, 1) == nil
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}
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// Unlock unlocks the semaphore.
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func (sema *Semaphore) Unlock() {
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sema.sema.Release(1)
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}
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