From b63a275e7a4ba4770de2584c035f2d9166e74102 Mon Sep 17 00:00:00 2001
From: Chris Howey <chris@howey.me>
Date: Tue, 9 Oct 2012 19:23:22 -0500
Subject: [PATCH] Golang exp/inotify fixes

http://code.google.com/p/go/issues/detail?id=3713
http://codereview.appspot.com/5418045/
---
 fsnotify_linux.go | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/fsnotify_linux.go b/fsnotify_linux.go
index 73c9a3c..07a047d 100644
--- a/fsnotify_linux.go
+++ b/fsnotify_linux.go
@@ -12,6 +12,7 @@ import (
 	"fmt"
 	"os"
 	"strings"
+	"sync"
 	"syscall"
 	"unsafe"
 )
@@ -46,6 +47,7 @@ type watch struct {
 }
 
 type Watcher struct {
+	mu            sync.Mutex        // Map access
 	fd            int               // File descriptor (as returned by the inotify_init() syscall)
 	watches       map[string]*watch // Map of inotify watches (key: path)
 	fsnFlags      map[string]uint32 // Map of watched files to flags used for filter
@@ -116,10 +118,11 @@ func (w *Watcher) addWatch(path string, flags uint32) error {
 		return errno
 	}
 
-	if !found {
-		w.watches[path] = &watch{wd: uint32(wd), flags: flags}
-		w.paths[wd] = path
-	}
+	w.mu.Lock()
+	w.watches[path] = &watch{wd: uint32(wd), flags: flags}
+	w.paths[wd] = path
+	w.mu.Unlock()
+
 	return nil
 }
 
@@ -191,7 +194,9 @@ func (w *Watcher) readEvents() {
 			// doesn't append the filename to the event, but we would like to always fill the
 			// the "Name" field with a valid filename. We retrieve the path of the watch from
 			// the "paths" map.
+			w.mu.Lock()
 			event.Name = w.paths[int(raw.Wd)]
+			w.mu.Unlock()
 			watchedName := event.Name
 			if nameLen > 0 {
 				// Point "bytes" at the first byte of the filename
-- 
2.50.1