SimpleSpanProcessor.Shutdown needs to be configurable with a timeout that it honors

[MrAlias]

The specification:

Shutdown SHOULD complete or abort within some timeout.

The already passed context should be used to determine if the method should abort. Similar to the batch span processor:

opentelemetry-go/sdk/trace/batch_span_processor.go

Lines 126 to 150 in 992837f

	// Shutdown flushes the queue and waits until all spans are processed.
	// It only executes once. Subsequent call does nothing.
	func (bsp *BatchSpanProcessor) Shutdown(ctx context.Context) error {
	var err error
	bsp.stopOnce.Do(func() {
	wait := make(chan struct{})
	go func() {
	close(bsp.stopCh)
	bsp.stopWait.Wait()
	if bsp.e != nil {
	if err := bsp.e.Shutdown(ctx); err != nil {
	otel.Handle(err)
	}
	}
	close(wait)
	}()
	// Wait until the wait group is done or the context is cancelled
	select {
	case <-wait:
	case <-ctx.Done():
	err = ctx.Err()
	}
	})
	return err
	}

Tests will need to be added to verify the behavior and that an appropriate error is returned when the deadline is reached or the context canceled.

[mrveera]

@MrAlias is it already being done by anyone or can i pick this up?

[MrAlias]

@veera83372 it has not, but I would wait for this to land prior to starting on something.

[mrveera]

@MrAlias Can i pick this now?

[MrAlias]

@veera83372 🚀