From 43297148b22b976d9cec0c56c863a704f3691c0e Mon Sep 17 00:00:00 2001
From: Unknwon <u@gogs.io>
Date: Tue, 30 Aug 2016 15:19:53 -0700
Subject: [PATCH] modules/sync: rename SingleInstancePool to ExclusivePool

---
 models/repo.go                                |  2 +-
 models/wiki.go                                |  2 +-
 ...gle_instance_pool.go => exclusive_pool.go} | 19 ++++++++++---------
 3 files changed, 12 insertions(+), 11 deletions(-)
 rename modules/sync/{single_instance_pool.go => exclusive_pool.go} (76%)

diff --git a/models/repo.go b/models/repo.go
index a26ba9248..8c6f86daf 100644
--- a/models/repo.go
+++ b/models/repo.go
@@ -40,7 +40,7 @@ const (
 	_TPL_UPDATE_HOOK = "#!/usr/bin/env %s\n%s update $1 $2 $3 --config='%s'\n"
 )
 
-var repoWorkingPool = sync.NewSingleInstancePool()
+var repoWorkingPool = sync.NewExclusivePool()
 
 var (
 	ErrRepoFileNotExist  = errors.New("Repository file does not exist")
diff --git a/models/wiki.go b/models/wiki.go
index f62cd2ac7..bc8aaf666 100644
--- a/models/wiki.go
+++ b/models/wiki.go
@@ -21,7 +21,7 @@ import (
 	"github.com/gogits/gogs/modules/sync"
 )
 
-var wikiWorkingPool = sync.NewSingleInstancePool()
+var wikiWorkingPool = sync.NewExclusivePool()
 
 // ToWikiPageURL formats a string to corresponding wiki URL name.
 func ToWikiPageURL(name string) string {
diff --git a/modules/sync/single_instance_pool.go b/modules/sync/exclusive_pool.go
similarity index 76%
rename from modules/sync/single_instance_pool.go
rename to modules/sync/exclusive_pool.go
index 01d95fd0b..744cc7c99 100644
--- a/modules/sync/single_instance_pool.go
+++ b/modules/sync/exclusive_pool.go
@@ -8,14 +8,15 @@ import (
 	"sync"
 )
 
-// SingleInstancePool is a pool of non-identical instances
+// ExclusivePool is a pool of non-identical instances
 // that only one instance with same identity is in the pool at a time.
-// In other words, only instances with different identities can exist
-// at the same time.
+// In other words, only instances with different identities can be in
+// the pool the same time. If another instance with same identity tries
+// to get into the pool, it hangs until previous instance left the pool.
 //
 // This pool is particularly useful for performing tasks on same resource
 // on the file system in different goroutines.
-type SingleInstancePool struct {
+type ExclusivePool struct {
 	lock sync.Mutex
 
 	// pool maintains locks for each instance in the pool.
@@ -29,9 +30,9 @@ type SingleInstancePool struct {
 	count map[string]int
 }
 
-// NewSingleInstancePool initializes and returns a new SingleInstancePool object.
-func NewSingleInstancePool() *SingleInstancePool {
-	return &SingleInstancePool{
+// NewExclusivePool initializes and returns a new ExclusivePool object.
+func NewExclusivePool() *ExclusivePool {
+	return &ExclusivePool{
 		pool:  make(map[string]*sync.Mutex),
 		count: make(map[string]int),
 	}
@@ -39,7 +40,7 @@ func NewSingleInstancePool() *SingleInstancePool {
 
 // CheckIn checks in an instance to the pool and hangs while instance
 // with same indentity is using the lock.
-func (p *SingleInstancePool) CheckIn(identity string) {
+func (p *ExclusivePool) CheckIn(identity string) {
 	p.lock.Lock()
 
 	lock, has := p.pool[identity]
@@ -55,7 +56,7 @@ func (p *SingleInstancePool) CheckIn(identity string) {
 
 // CheckOut checks out an instance from the pool and releases the lock
 // to let other instances with same identity to grab the lock.
-func (p *SingleInstancePool) CheckOut(identity string) {
+func (p *ExclusivePool) CheckOut(identity string) {
 	p.lock.Lock()
 	defer p.lock.Unlock()