76 lines
1.0 KiB
Go
76 lines
1.0 KiB
Go
package expirelock
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import (
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"context"
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"errors"
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"expirelock/os"
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"sync"
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"sync/atomic"
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"time"
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)
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type Block struct {
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token atomic.Value
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mu sync.Mutex
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dmu sync.Mutex
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celFu context.CancelFunc
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}
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func NewBlock() *Block {
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return &Block{}
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}
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func (b *Block) Lock(ttl time.Duration) error {
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b.mu.Lock()
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b.dmu.Lock()
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defer b.dmu.Unlock()
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token := os.GetCurrentProcessAndGogroutineIDStr()
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b.token.Store(token)
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b.celFu = nil
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if ttl <= 0 {
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return nil
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}
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var ctx context.Context
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ctx, b.celFu = context.WithCancel(context.Background())
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go func() {
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select {
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case <-ctx.Done():
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return
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case <-time.After(ttl):
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_ = b.unlock(token)
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}
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}()
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return nil
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}
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func (b *Block) unlock(token string) error {
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b.dmu.Lock()
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defer b.dmu.Unlock()
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id, _ := b.token.Load().(string)
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if id != token {
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return errors.New("invalid token")
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}
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if b.celFu != nil {
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b.celFu()
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}
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b.token.Store("")
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b.mu.Unlock()
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return nil
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}
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func (b *Block) Unlock() error {
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token := os.GetCurrentProcessAndGogroutineIDStr()
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return b.unlock(token)
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}
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