go.temporal.io/server/common/clock/context.go

74 LOC · 39 covered · 35 uncovered · 9 ranges · 26 concepts · 7 introducers · 16 tests

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  package clock
  
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  import (
  
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  	"context"
  
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  	"sync"
  
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  	"time"
  
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  )
  
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  type ctxWithDeadline struct {
  
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  	context.Context
  
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  	deadline time.Time
  
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  	timer    Timer
  
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  	once     sync.Once
  
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  	done     chan struct{}
  
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  	err      error
  
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  }
  
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  >
  func (ctx *ctxWithDeadline) Deadline() (deadline time.Time, ok bool) {
  
context.go ×1

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  	return ctx.deadline, true
  
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  }
  
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  func (ctx *ctxWithDeadline) Done() <-chan struct{} {
  
context.go ×1

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  	return ctx.done
  
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  }
  
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  func (ctx *ctxWithDeadline) Err() error {
  
context.go ×1

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  	select {
  
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  	case <-ctx.done:
  
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  		return ctx.err
  
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  	default:
  
context.go ×1

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  		return nil
  
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  	}
  
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  }
  
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  func (ctx *ctxWithDeadline) deadlineExceeded() {
  
context.go ×1

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  	ctx.once.Do(func() {
  
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  		ctx.err = context.DeadlineExceeded
  
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  		close(ctx.done)
  
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  	})
  
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  }
  
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  func (ctx *ctxWithDeadline) cancel() {
  
context.go ×3

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  	ctx.once.Do(func() {
  
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  		// We'd like to call ctx.timer.Stop() here, but we can't: the time source may call
  
context.go ×1

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  		// deadlineExceeded while holding its lock, which acquires the once mutex. Here we have
  
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  		// the once mutex and want to cancel a timer, which would create a potential lock
  
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  		// cycle. So just leave the timer as a no-op.
  
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  		ctx.err = context.Canceled
  
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  		close(ctx.done)
  
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  	})
  
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  }
  
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  func ContextWithDeadline(
  
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  	ctx context.Context,
  
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  	deadline time.Time,
  
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  	timeSource TimeSource,
  
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  ) (context.Context, context.CancelFunc) {
  
context.go ×3

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  	ctxd := &ctxWithDeadline{
  
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  		Context:  ctx,
  
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  		deadline: deadline,
  
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  		done:     make(chan struct{}),
  
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  	}
  
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  	timer := timeSource.AfterFunc(deadline.Sub(timeSource.Now()), ctxd.deadlineExceeded)
  
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  	ctxd.timer = timer
  
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  	return ctxd, ctxd.cancel
  
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  }
  
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  func ContextWithTimeout(
  
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  	ctx context.Context,
  
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  	timeout time.Duration,
  
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  	timeSource TimeSource,
  
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  ) (context.Context, context.CancelFunc) {
  
context.go ×3

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  	return ContextWithDeadline(ctx, timeSource.Now().Add(timeout), timeSource)
  
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  }