From bcdea2adb44989baf591bc5dd8f5d56d04f2c98c Mon Sep 17 00:00:00 2001
From: Boris Suvorov <boris@rodinhood.com>
Date: Mon, 6 Jul 2015 19:20:50 -0700
Subject: [PATCH] Cache nonParameterCharacterSet to help minimize memory
 footprint in multithreaded apps using SOCKit

Relevant github.com pull request into SOCKit is located here: https://github.com/NimbusKit/sockit/pull/26
---
 src/SOCKit.m | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/SOCKit.m b/src/SOCKit.m
index 33fbf11..0c7bafb 100644
--- a/src/SOCKit.m
+++ b/src/SOCKit.m
@@ -72,11 +72,13 @@ - (id)copyWithZone:(NSZone *)zone {
 
 - (NSCharacterSet *)nonParameterCharacterSet {
   static NSCharacterSet* staticNonParameterCharacterSet = nil;
-  if (staticNonParameterCharacterSet == nil) {
+  static dispatch_once_t onceToken;
+  dispatch_once(&onceToken, ^{
     NSMutableCharacterSet* parameterCharacterSet = [NSMutableCharacterSet alphanumericCharacterSet];
     [parameterCharacterSet addCharactersInString:@".@_"];
     staticNonParameterCharacterSet = [parameterCharacterSet invertedSet];
-  }
+  });
+
   return staticNonParameterCharacterSet;
 }