From 9929bcc40d57e580af82a105ba530a7d9640e27c Mon Sep 17 00:00:00 2001
From: Martin Holst Swende <martin@swende.se>
Date: Mon, 14 Aug 2017 15:17:51 +0200
Subject: [PATCH] account/keystore : make fs watcher use not block account ops
 during fs scan

---
 accounts/keystore/account_cache.go | 6 ++++++
 accounts/keystore/watch.go         | 3 ++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/accounts/keystore/account_cache.go b/accounts/keystore/account_cache.go
index dc6ac6ccb3..77c19ddd9f 100644
--- a/accounts/keystore/account_cache.go
+++ b/accounts/keystore/account_cache.go
@@ -209,6 +209,12 @@ func (ac *accountCache) close() {
 // Callers must hold ac.mu.
 func (ac *accountCache) reload() {
 	accounts, err := ac.scan()
+	ac.handleScanResult(accounts, err)
+}
+
+// handleScanResult uses the result of a fs scan to update the account lists
+// This can be used to perform un-mutexed fs scans
+func (ac *accountCache) handleScanResult(accounts []accounts.Account, err error) {
 	if err != nil {
 		log.Debug("Failed to reload keystore contents", "err", err)
 	}
diff --git a/accounts/keystore/watch.go b/accounts/keystore/watch.go
index f4d6477912..363587223d 100644
--- a/accounts/keystore/watch.go
+++ b/accounts/keystore/watch.go
@@ -99,8 +99,9 @@ func (w *watcher) loop() {
 				hadEvent = true
 			}
 		case <-debounce.C:
+			accounts, err := w.ac.scan()
 			w.ac.mu.Lock()
-			w.ac.reload()
+			w.ac.handleScanResult(accounts, err)
 			w.ac.mu.Unlock()
 			if hadEvent {
 				debounce.Reset(debounceDuration)