From e8bf18c0b448f6d30d2921be6af87c911f3c4571 Mon Sep 17 00:00:00 2001
From: Evgenii Stratonikov <evgeniy@nspcc.ru>
Date: Mon, 4 Apr 2022 10:07:33 +0300
Subject: [PATCH] [#1208] innerring: Fix race condition between handling new
 epoch and block

Before resetting the timer, ensure the block tick is processed.

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
---
 .../processors/netmap/process_epoch.go        | 10 +++++-
 pkg/innerring/processors/netmap/processor.go  |  2 +-
 pkg/innerring/state.go                        |  3 +-
 pkg/morph/client/client.go                    | 12 +++++++
 pkg/morph/timer/block_test.go                 | 35 +++++++++++++++++++
 5 files changed, 59 insertions(+), 3 deletions(-)

diff --git a/pkg/innerring/processors/netmap/process_epoch.go b/pkg/innerring/processors/netmap/process_epoch.go
index b2cefbcb..cf763383 100644
--- a/pkg/innerring/processors/netmap/process_epoch.go
+++ b/pkg/innerring/processors/netmap/process_epoch.go
@@ -23,7 +23,15 @@ func (np *Processor) processNewEpoch(ev netmapEvent.NewEpoch) {
 	}
 
 	np.epochState.SetEpochCounter(epoch)
-	if err := np.epochTimer.ResetEpochTimer(); err != nil {
+
+	h, err := np.netmapClient.Morph().TxHeight(ev.TxHash())
+	if err != nil {
+		np.log.Warn("can't get transaction height",
+			zap.String("hash", ev.TxHash().StringLE()),
+			zap.String("error", err.Error()))
+	}
+
+	if err := np.epochTimer.ResetEpochTimer(h); err != nil {
 		np.log.Warn("can't reset epoch timer",
 			zap.String("error", err.Error()))
 	}
diff --git a/pkg/innerring/processors/netmap/processor.go b/pkg/innerring/processors/netmap/processor.go
index 8734850f..430a6819 100644
--- a/pkg/innerring/processors/netmap/processor.go
+++ b/pkg/innerring/processors/netmap/processor.go
@@ -19,7 +19,7 @@ import (
 type (
 	// EpochTimerReseter is a callback interface for tickers component.
 	EpochTimerReseter interface {
-		ResetEpochTimer() error
+		ResetEpochTimer(uint32) error
 	}
 
 	// EpochState is a callback interface for inner ring global state.
diff --git a/pkg/innerring/state.go b/pkg/innerring/state.go
index 1808cee6..e079c68d 100644
--- a/pkg/innerring/state.go
+++ b/pkg/innerring/state.go
@@ -160,7 +160,8 @@ func (s *Server) WriteReport(r *audit.Report) error {
 // ResetEpochTimer resets block timer that produces events to update epoch
 // counter in netmap contract. Used to synchronize this even production
 // based on block with notification of last epoch.
-func (s *Server) ResetEpochTimer() error {
+func (s *Server) ResetEpochTimer(h uint32) error {
+	s.epochTimer.Tick(h)
 	return s.epochTimer.Reset()
 }
 
diff --git a/pkg/morph/client/client.go b/pkg/morph/client/client.go
index 14301e17..ebc756f2 100644
--- a/pkg/morph/client/client.go
+++ b/pkg/morph/client/client.go
@@ -341,6 +341,18 @@ func (c *Client) TxHalt(h util.Uint256) (res bool, err error) {
 	return len(aer.Executions) > 0 && aer.Executions[0].VMState.HasFlag(vm.HaltState), nil
 }
 
+// TxHeight returns true if transaction has been successfully executed and persisted.
+func (c *Client) TxHeight(h util.Uint256) (res uint32, err error) {
+	if c.multiClient != nil {
+		return res, c.multiClient.iterateClients(func(c *Client) error {
+			res, err = c.TxHeight(h)
+			return err
+		})
+	}
+
+	return c.client.GetTransactionHeight(h)
+}
+
 // NeoFSAlphabetList returns keys that stored in NeoFS Alphabet role. Main chain
 // stores alphabet node keys of inner ring there, however side chain stores both
 // alphabet and non alphabet node keys of inner ring.
diff --git a/pkg/morph/timer/block_test.go b/pkg/morph/timer/block_test.go
index 2d4afc4e..59b484e6 100644
--- a/pkg/morph/timer/block_test.go
+++ b/pkg/morph/timer/block_test.go
@@ -13,6 +13,41 @@ func tickN(t *timer.BlockTimer, n uint32) {
 	}
 }
 
+// This test emulates inner-ring handling of a new epoch and a new block.
+// "resetting" consists of ticking the current height as well and invoking `Reset`.
+func TestIRBlockTimer_Reset(t *testing.T) {
+	var baseCounter [2]int
+	blockDur := uint32(3)
+
+	bt1 := timer.NewBlockTimer(
+		func() (uint32, error) { return blockDur, nil },
+		func() { baseCounter[0]++ })
+	bt2 := timer.NewBlockTimer(
+		func() (uint32, error) { return blockDur, nil },
+		func() { baseCounter[1]++ })
+
+	require.NoError(t, bt1.Reset())
+	require.NoError(t, bt2.Reset())
+
+	run := func(bt *timer.BlockTimer, direct bool) {
+		if direct {
+			bt.Tick(1)
+			require.NoError(t, bt.Reset())
+			bt.Tick(1)
+		} else {
+			bt.Tick(1)
+			bt.Tick(1)
+			require.NoError(t, bt.Reset())
+		}
+		bt.Tick(2)
+		bt.Tick(3)
+	}
+
+	run(bt1, true)
+	run(bt2, false)
+	require.Equal(t, baseCounter[0], baseCounter[1])
+}
+
 func TestBlockTimer(t *testing.T) {
 	blockDur := uint32(10)
 	baseCallCounter := uint32(0)