Made cache thread-safe

10 years ago · dda9a3cd36
parent ec4e5cf212
commit dda9a3cd36
1 changed files with 6 additions and 6 deletions
--- a/src/objective-c/GRPCClient/private/GRPCChannel.m
+++ b/src/objective-c/GRPCClient/private/GRPCChannel.m
@ -40,15 +40,15 @@

@implementation GRPCChannel

-// TODO(mlumish): Investigate whether a cache with strong links is a good idea
-static NSMutableDictionary *channelCache;
-
 + (instancetype)channelToHost:(NSString *)host {
-  if (channelCache == nil) {
+  // TODO(mlumish): Investigate whether a cache with strong links is a good idea
+  static NSMutableDictionary *channelCache;
+  static dispatch_once_t cacheInitialization;
+  dispatch_once(&cacheInitialization, ^{
    channelCache = [NSMutableDictionary dictionary];
-  }
+  });
  GRPCChannel *channel = channelCache[host];
-  if (channel == nil) {
+  if (!channel) {
    channel = [[self alloc] initWithHost:host];
    channelCache[host] = channel;
  }