From f2dd0f046ebfc575b4008a36929c4b3b09e38826 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Magiera?= <magik6k@gmail.com>
Date: Tue, 7 Apr 2020 20:02:52 +0200
Subject: [PATCH] wdpost: Make chain notif loop reconnect friendly

---
 storage/wdpost_sched.go | 55 +++++++++++++++++++++++++++--------------
 1 file changed, 37 insertions(+), 18 deletions(-)

diff --git a/storage/wdpost_sched.go b/storage/wdpost_sched.go
index c4c319931..4838fe51e 100644
--- a/storage/wdpost_sched.go
+++ b/storage/wdpost_sched.go
@@ -3,6 +3,7 @@ package storage
 import (
 	"context"
 	"sync"
+	"time"
 
 	"go.opencensus.io/trace"
 	"golang.org/x/xerrors"
@@ -43,32 +44,50 @@ func NewWindowedPoStScheduler(api storageMinerApi, sb storage.Prover, actor addr
 }
 
 func (s *WindowPoStScheduler) Run(ctx context.Context) {
-	notifs, err := s.api.ChainNotify(ctx)
-	if err != nil {
-		return
-	}
-
-	current := <-notifs
-	if len(current) != 1 {
-		panic("expected first notif to have len = 1")
-	}
-	if current[0].Type != store.HCCurrent {
-		panic("expected first notif to tell current ts")
-	}
-
-	if err := s.update(ctx, current[0].Val); err != nil {
-		panic(err)
-	}
-
 	defer s.abortActivePoSt()
 
+	var notifs <-chan []*store.HeadChange
+	var err error
+	var gotCur bool
+
 	// not fine to panic after this point
 	for {
+		if notifs == nil {
+			notifs, err = s.api.ChainNotify(ctx)
+			if err != nil {
+				log.Errorf("ChainNotify error: %+v")
+
+				time.Sleep(10 * time.Second)
+				continue
+			}
+
+			gotCur = false
+		}
+
 		select {
 		case changes, ok := <-notifs:
 			if !ok {
 				log.Warn("WindowPoStScheduler notifs channel closed")
-				return
+				notifs = nil
+				continue
+			}
+
+			if !gotCur {
+				if len(changes) != 1 {
+					log.Errorf("expected first notif to have len = 1")
+					continue
+				}
+				if changes[0].Type != store.HCCurrent {
+					log.Errorf("expected first notif to tell current ts")
+					continue
+				}
+
+				if err := s.update(ctx, changes[0].Val); err != nil {
+					log.Errorf("%+v", err)
+				}
+
+				gotCur = true
+				continue
 			}
 
 			ctx, span := trace.StartSpan(ctx, "WindowPoStScheduler.headChange")