From 86f4034ceaa724c38c5126cd8a25a6ed5308f59c Mon Sep 17 00:00:00 2001
From: Lunny Xiao <xiaolunwen@gmail.com>
Date: Tue, 8 Sep 2020 12:43:28 +0800
Subject: [PATCH] Fix data race when batch.Reset. Fix #1460

---
 index/scorch/scorch.go         |  8 +++++---
 index/upsidedown/upsidedown.go | 10 ++++++----
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/index/scorch/scorch.go b/index/scorch/scorch.go
index ba98a460d..f23648c7b 100644
--- a/index/scorch/scorch.go
+++ b/index/scorch/scorch.go
@@ -334,15 +334,17 @@ func (s *Scorch) Batch(batch *index.Batch) (err error) {
 	// FIXME could sort ids list concurrent with analysis?
 
 	if numUpdates > 0 {
-		go func() {
-			for _, doc := range batch.IndexOps {
+		// batch.IndexOps maybe reseted when the goroutine is running, so
+		// we should send a copy of it.
+		go func(ops map[string]*document.Document) {
+			for _, doc := range ops {
 				if doc != nil {
 					aw := index.NewAnalysisWork(s, doc, resultChan)
 					// put the work on the queue
 					s.analysisQueue.Queue(aw)
 				}
 			}
-		}()
+		}(batch.IndexOps)
 	}
 
 	// wait for analysis result
diff --git a/index/upsidedown/upsidedown.go b/index/upsidedown/upsidedown.go
index 8e915c6ad..d84a03302 100644
--- a/index/upsidedown/upsidedown.go
+++ b/index/upsidedown/upsidedown.go
@@ -819,16 +819,18 @@ func (udc *UpsideDownCouch) Batch(batch *index.Batch) (err error) {
 	}
 
 	if numUpdates > 0 {
-		go func() {
-			for k := range batch.IndexOps {
-				doc := batch.IndexOps[k]
+		// batch.IndexOps maybe reseted when the goroutine is running, so
+		// we should send a copy of it.
+		go func(ops map[string]*document.Document) {
+			for k := range ops {
+				doc := ops[k]
 				if doc != nil {
 					aw := index.NewAnalysisWork(udc, doc, resultChan)
 					// put the work on the queue
 					udc.analysisQueue.Queue(aw)
 				}
 			}
-		}()
+		}(batch.IndexOps)
 	}
 
 	// retrieve back index rows concurrent with analysis