From 0310bcbb11f858d132725b2aa3d4d16021aa4193 Mon Sep 17 00:00:00 2001
From: Paul Bellamy <paul@stellar.org>
Date: Thu, 28 Jul 2022 14:56:08 +0100
Subject: [PATCH] mutex around a global variable to avoid data race

---
 .../horizon/internal/ingest/filters/main.go    | 18 ++++++++++++++++--
 .../integration/ingestion_filtering_test.go    |  8 ++++----
 2 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/services/horizon/internal/ingest/filters/main.go b/services/horizon/internal/ingest/filters/main.go
index 94e762d0ac..06532e5848 100644
--- a/services/horizon/internal/ingest/filters/main.go
+++ b/services/horizon/internal/ingest/filters/main.go
@@ -2,6 +2,7 @@ package filters
 
 import (
 	"context"
+	"sync"
 	"time"
 
 	"github.com/stellar/go/services/horizon/internal/db2/history"
@@ -13,9 +14,22 @@ var (
 
 	// the filter config cache will be checked against latest from db at most once per each of this interval.
 	//lint:ignore ST1011, don't need the linter warn on literal assignment
-	FilterConfigCheckIntervalSeconds time.Duration = 100
+	filterConfigCheckIntervalSeconds     time.Duration = 100
+	filterConfigCheckIntervalSecondsLock sync.RWMutex
 )
 
+func GetFilterConfigCheckIntervalSeconds() time.Duration {
+	filterConfigCheckIntervalSecondsLock.RLock()
+	defer filterConfigCheckIntervalSecondsLock.RUnlock()
+	return filterConfigCheckIntervalSeconds
+}
+
+func SetFilterConfigCheckIntervalSeconds(t time.Duration) {
+	filterConfigCheckIntervalSecondsLock.Lock()
+	defer filterConfigCheckIntervalSecondsLock.Unlock()
+	filterConfigCheckIntervalSeconds = t
+}
+
 var (
 	LOG = log.WithFields(log.F{
 		"filters": "load",
@@ -43,7 +57,7 @@ func NewFilters() Filters {
 // rebuild the list on expiration time interval. Method is NOT thread-safe.
 func (f *filtersCache) GetFilters(filterQ history.QFilter, ctx context.Context) []processors.LedgerTransactionFilterer {
 	// only attempt to refresh filter config cache state at configured interval limit
-	if time.Now().Unix() < (f.lastFilterConfigCheckUnixEpoch + int64(FilterConfigCheckIntervalSeconds.Seconds())) {
+	if time.Now().Unix() < (f.lastFilterConfigCheckUnixEpoch + int64(GetFilterConfigCheckIntervalSeconds().Seconds())) {
 		return f.convertCacheToList()
 	}
 
diff --git a/services/horizon/internal/integration/ingestion_filtering_test.go b/services/horizon/internal/integration/ingestion_filtering_test.go
index 8eca0f3aa1..47cfc1ccbc 100644
--- a/services/horizon/internal/integration/ingestion_filtering_test.go
+++ b/services/horizon/internal/integration/ingestion_filtering_test.go
@@ -48,7 +48,7 @@ func TestFilteringAccountWhiteList(t *testing.T) {
 	tt.NoError(err)
 
 	// Setup a whitelisted account rule, force refresh of filter configs to be quick
-	filters.FilterConfigCheckIntervalSeconds = 1
+	filters.SetFilterConfigCheckIntervalSeconds(1)
 
 	expectedAccountFilter := hProtocol.AccountFilterConfig{
 		Whitelist: []string{whitelistedAccount.GetAccountID()},
@@ -64,7 +64,7 @@ func TestFilteringAccountWhiteList(t *testing.T) {
 	tt.Equal(expectedAccountFilter.Enabled, accountFilter.Enabled)
 
 	// Ensure the latest filter configs are reloaded by the ingestion state machine processor
-	time.Sleep(time.Duration(filters.FilterConfigCheckIntervalSeconds) * time.Second)
+	time.Sleep(time.Duration(filters.GetFilterConfigCheckIntervalSeconds()) * time.Second)
 
 	// Make sure that when using a non-whitelisted account, the transaction is not stored
 	txResp = itest.MustSubmitOperations(itest.MasterAccount(), itest.Master(),
@@ -123,7 +123,7 @@ func TestFilteringAssetWhiteList(t *testing.T) {
 	tt.NoError(err)
 
 	// Setup a whitelisted asset rule, force refresh of filters to be quick
-	filters.FilterConfigCheckIntervalSeconds = 1
+	filters.SetFilterConfigCheckIntervalSeconds(1)
 
 	asset, err := whitelistedAsset.ToXDR()
 	tt.NoError(err)
@@ -141,7 +141,7 @@ func TestFilteringAssetWhiteList(t *testing.T) {
 	tt.Equal(expectedAssetFilter.Enabled, assetFilter.Enabled)
 
 	// Ensure the latest filter configs are reloaded by the ingestion state machine processor
-	time.Sleep(time.Duration(filters.FilterConfigCheckIntervalSeconds) * time.Second)
+	time.Sleep(time.Duration(filters.GetFilterConfigCheckIntervalSeconds()) * time.Second)
 
 	// Make sure that when using a non-whitelisted asset, the transaction is not stored
 	txResp = itest.MustSubmitOperations(itest.MasterAccount(), itest.Master(),