From ab7da86b06233b325406d8b0fb5ff0902adec001 Mon Sep 17 00:00:00 2001
From: "M. J. Fromberger" <fromberger@interchain.io>
Date: Tue, 14 Dec 2021 15:14:30 -0800
Subject: [PATCH] Internalize libs/sync. (#7450)

Inline the one usage of this library, and remove the lib.
---
 CHANGELOG_PENDING.md          |  1 +
 internal/blocksync/reactor.go | 28 +++++++++++++++++++++++++---
 libs/sync/atomic_bool.go      | 33 ---------------------------------
 libs/sync/atomic_bool_test.go | 27 ---------------------------
 4 files changed, 26 insertions(+), 63 deletions(-)
 delete mode 100644 libs/sync/atomic_bool.go
 delete mode 100644 libs/sync/atomic_bool_test.go

diff --git a/CHANGELOG_PENDING.md b/CHANGELOG_PENDING.md
index 4b3c53a4c..3e54a230b 100644
--- a/CHANGELOG_PENDING.md
+++ b/CHANGELOG_PENDING.md
@@ -27,6 +27,7 @@ Special thanks to external contributors on this release:
 
 - Go API
 
+  - [libs/sync] \#7450 Internalize and remove the library. (@creachadair)
   - [libs/async] \#7449 Move library to internal. (@creachadair)
   - [pubsub] \#7231 Remove unbuffered subscriptions and rework the Subscription interface. (@creachadair)
   - [eventbus] \#7231 Move the EventBus type to the internal/eventbus package. (@creachadair)
diff --git a/internal/blocksync/reactor.go b/internal/blocksync/reactor.go
index 7ff785c81..ee745fb92 100644
--- a/internal/blocksync/reactor.go
+++ b/internal/blocksync/reactor.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"runtime/debug"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/tendermint/tendermint/internal/consensus"
@@ -14,7 +15,6 @@ import (
 	"github.com/tendermint/tendermint/internal/store"
 	"github.com/tendermint/tendermint/libs/log"
 	"github.com/tendermint/tendermint/libs/service"
-	tmsync "github.com/tendermint/tendermint/libs/sync"
 	bcproto "github.com/tendermint/tendermint/proto/tendermint/blocksync"
 	"github.com/tendermint/tendermint/types"
 )
@@ -75,7 +75,7 @@ type Reactor struct {
 	store       *store.BlockStore
 	pool        *BlockPool
 	consReactor consensusReactor
-	blockSync   *tmsync.AtomicBool
+	blockSync   *atomicBool
 
 	blockSyncCh *p2p.Channel
 	// blockSyncOutBridgeCh defines a channel that acts as a bridge between sending Envelope
@@ -132,7 +132,7 @@ func NewReactor(
 		store:                store,
 		pool:                 NewBlockPool(logger, startHeight, requestsCh, errorsCh),
 		consReactor:          consReactor,
-		blockSync:            tmsync.NewBool(blockSync),
+		blockSync:            newAtomicBool(blockSync),
 		requestsCh:           requestsCh,
 		errorsCh:             errorsCh,
 		blockSyncCh:          blockSyncCh,
@@ -625,3 +625,25 @@ func (r *Reactor) GetRemainingSyncTime() time.Duration {
 
 	return time.Duration(int64(remain * float64(time.Second)))
 }
+
+// atomicBool is an atomic Boolean, safe for concurrent use by multiple
+// goroutines.
+type atomicBool int32
+
+// newAtomicBool creates an atomicBool with given initial value.
+func newAtomicBool(ok bool) *atomicBool {
+	ab := new(atomicBool)
+	if ok {
+		ab.Set()
+	}
+	return ab
+}
+
+// Set sets the Boolean to true.
+func (ab *atomicBool) Set() { atomic.StoreInt32((*int32)(ab), 1) }
+
+// UnSet sets the Boolean to false.
+func (ab *atomicBool) UnSet() { atomic.StoreInt32((*int32)(ab), 0) }
+
+// IsSet returns whether the Boolean is true.
+func (ab *atomicBool) IsSet() bool { return atomic.LoadInt32((*int32)(ab))&1 == 1 }
diff --git a/libs/sync/atomic_bool.go b/libs/sync/atomic_bool.go
deleted file mode 100644
index 1a530b596..000000000
--- a/libs/sync/atomic_bool.go
+++ /dev/null
@@ -1,33 +0,0 @@
-package sync
-
-import "sync/atomic"
-
-// AtomicBool is an atomic Boolean.
-// Its methods are all atomic, thus safe to be called by multiple goroutines simultaneously.
-// Note: When embedding into a struct one should always use *AtomicBool to avoid copy.
-// it's a simple implmentation from https://github.com/tevino/abool
-type AtomicBool int32
-
-// NewBool creates an AtomicBool with given default value.
-func NewBool(ok bool) *AtomicBool {
-	ab := new(AtomicBool)
-	if ok {
-		ab.Set()
-	}
-	return ab
-}
-
-// Set sets the Boolean to true.
-func (ab *AtomicBool) Set() {
-	atomic.StoreInt32((*int32)(ab), 1)
-}
-
-// UnSet sets the Boolean to false.
-func (ab *AtomicBool) UnSet() {
-	atomic.StoreInt32((*int32)(ab), 0)
-}
-
-// IsSet returns whether the Boolean is true.
-func (ab *AtomicBool) IsSet() bool {
-	return atomic.LoadInt32((*int32)(ab))&1 == 1
-}
diff --git a/libs/sync/atomic_bool_test.go b/libs/sync/atomic_bool_test.go
deleted file mode 100644
index 9531815e8..000000000
--- a/libs/sync/atomic_bool_test.go
+++ /dev/null
@@ -1,27 +0,0 @@
-package sync
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestDefaultValue(t *testing.T) {
-	t.Parallel()
-	v := NewBool(false)
-	assert.False(t, v.IsSet())
-
-	v = NewBool(true)
-	assert.True(t, v.IsSet())
-}
-
-func TestSetUnSet(t *testing.T) {
-	t.Parallel()
-	v := NewBool(false)
-
-	v.Set()
-	assert.True(t, v.IsSet())
-
-	v.UnSet()
-	assert.False(t, v.IsSet())
-}