V3

Rewrite with a task-oriented focus, with database-backed task queues (using sqlite). Testing has been improved significantly too.

database.go

@@ -142,7 +142,13 @@ func popTask(tx *sql.Tx, now int64) (*Task, error) {
 	return t, err
 }
 
-func pushTask(tx *sql.Tx, t *Task) error {
+func pushTask(tx *sql.Tx, t *Task, now time.Time) error {
+	// Sanity check to prevent errors where we never break out of
+	// the inner queue loop.
+	if !t.Deadline.After(now) {
+		panic("inserting task with deadline < now, potential deadlock!")
+	}
+
 	log.Printf("pushing transition %s", t.debugString())
 	_, err := tx.Exec(
 		"INSERT INTO tasks (id, op, deadline, failure_count, certificate, chain, private_key, not_after) VALUES (?, ?, ?, ?, ?, ?, ?, ?)",
@@ -164,13 +170,14 @@ func forceRenewal(tx *sql.Tx, hash uint64) error {
 	if err != nil {
 		return err
 	}
+	now := time.Now()
 	return pushTask(tx, &Task{
 		IntentCert: IntentCert{
 			Hash: hash,
 		},
 		Op:       OpRenew,
-		Deadline: time.Now(),
-	})
+		Deadline: now,
+	}, now)
 }
 
 func cleanupOldTasks(tx *sql.Tx) error {