From 5b972294f847d9da027be117cb198eded4125207 Mon Sep 17 00:00:00 2001
From: Armon Dadgar <armon.dadgar@gmail.com>
Date: Wed, 7 Jan 2015 15:48:27 -0800
Subject: [PATCH] consul: Enforce lock-delay with delete behavior

---
 consul/state_store.go      | 60 +++++++++++++++++++++++++++++---------
 consul/state_store_test.go | 10 +++++--
 2 files changed, 54 insertions(+), 16 deletions(-)

diff --git a/consul/state_store.go b/consul/state_store.go
index 104253418..71a9d6bf6 100644
--- a/consul/state_store.go
+++ b/consul/state_store.go
@@ -1784,23 +1784,19 @@ func (s *StateStore) invalidateSession(index uint64, tx *MDBTxn, id string) erro
 	}
 	session := res[0].(*structs.Session)
 
+	// Enforce the MaxLockDelay
+	delay := session.LockDelay
+	if delay > structs.MaxLockDelay {
+		delay = structs.MaxLockDelay
+	}
+
+	// Invalidate any held locks
 	if session.Behavior == structs.SessionKeysDelete {
-		// delete the keys held by the session
-		if err := s.kvsDeleteWithIndexTxn(index, tx, "session", id); err != nil {
-			return err
-		}
-
-	} else { // default to release
-		// Enforce the MaxLockDelay
-		delay := session.LockDelay
-		if delay > structs.MaxLockDelay {
-			delay = structs.MaxLockDelay
-		}
-
-		// Invalidate any held locks
-		if err := s.invalidateLocks(index, tx, delay, id); err != nil {
+		if err := s.deleteLocks(index, tx, delay, id); err != nil {
 			return err
 		}
+	} else if err := s.invalidateLocks(index, tx, delay, id); err != nil {
+		return err
 	}
 
 	// Nuke the session
@@ -1867,6 +1863,42 @@ func (s *StateStore) invalidateLocks(index uint64, tx *MDBTxn,
 	return nil
 }
 
+// deleteLocks is used to delete all the locks held by a session
+// within a given txn. All tables should be locked in the tx.
+func (s *StateStore) deleteLocks(index uint64, tx *MDBTxn,
+	lockDelay time.Duration, id string) error {
+	pairs, err := s.kvsTable.GetTxn(tx, "session", id)
+	if err != nil {
+		return err
+	}
+
+	var expires time.Time
+	if lockDelay > 0 {
+		s.lockDelayLock.Lock()
+		defer s.lockDelayLock.Unlock()
+		expires = time.Now().Add(lockDelay)
+	}
+
+	for _, pair := range pairs {
+		kv := pair.(*structs.DirEntry)
+		if err := s.kvsDeleteWithIndexTxn(index, tx, "id", kv.Key); err != nil {
+			return err
+		}
+
+		// If there is a lock delay, prevent acquisition
+		// for at least lockDelay period
+		if lockDelay > 0 {
+			s.lockDelay[kv.Key] = expires
+			time.AfterFunc(lockDelay, func() {
+				s.lockDelayLock.Lock()
+				delete(s.lockDelay, kv.Key)
+				s.lockDelayLock.Unlock()
+			})
+		}
+	}
+	return nil
+}
+
 // ACLSet is used to create or update an ACL entry
 func (s *StateStore) ACLSet(index uint64, acl *structs.ACL) error {
 	// Check for an ID
diff --git a/consul/state_store_test.go b/consul/state_store_test.go
index de4d4ebbe..463733467 100644
--- a/consul/state_store_test.go
+++ b/consul/state_store_test.go
@@ -2731,7 +2731,7 @@ func TestSessionInvalidate_KeyDelete(t *testing.T) {
 	}
 
 	notify1 := make(chan struct{}, 1)
-	store.WatchKV("/f", notify1)
+	store.WatchKV("/b", notify1)
 
 	// Delete the node
 	if err := store.DeleteNode(6, "foo"); err != nil {
@@ -2748,7 +2748,13 @@ func TestSessionInvalidate_KeyDelete(t *testing.T) {
 	select {
 	case <-notify1:
 	default:
-		t.Fatalf("should notify /f")
+		t.Fatalf("should notify /b")
+	}
+
+	// Key should have a lock delay
+	expires := store.KVSLockDelay("/bar")
+	if expires.Before(time.Now().Add(30 * time.Millisecond)) {
+		t.Fatalf("Bad: %v", expires)
 	}
 }