X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/1af97b61b072f470a495bbcfd8e2626c031ef57b..6fa7f9fbcf20aa866eed0618bd09e1ce2e109baa:/services/keep-web/handler.go

diff --git a/services/keep-web/handler.go b/services/keep-web/handler.go
index 4fae0aee5f..b9250efec7 100644
--- a/services/keep-web/handler.go
+++ b/services/keep-web/handler.go
@@ -435,6 +435,14 @@ func (h *handler) ServeHTTP(wOrig http.ResponseWriter, r *http.Request) {
 		break
 	}
 
+	// releaseSession() is equivalent to session.Release() except
+	// that it's a no-op if (1) session is nil, or (2) it has
+	// already been called.
+	//
+	// This way, we can do a defer call here to ensure it gets
+	// called in all code paths, and also call it inline (see
+	// below) in the cases where we want to release the lock
+	// before returning.
 	releaseSession := func() {}
 	if session != nil {
 		var releaseSessionOnce sync.Once
@@ -603,7 +611,7 @@ func (h *handler) ServeHTTP(wOrig http.ResponseWriter, r *http.Request) {
 		// When writing, we need to block session renewal
 		// until we're finished, in order to guarantee the
 		// effect of the write is visible in future responses.
-		// But if we're not writing, we can release the lcok
+		// But if we're not writing, we can release the lock
 		// early.  This enables us to keep renewing sessions
 		// and processing more requests even if a slow client
 		// takes a long time to download a large file.