Avoid using global Mutex variables (#1252)

After 5c9815f, some Mutexes are used as global C++ variables which are loaded before main(). Since the Mutex constructor checks for unfair lock experiment, it triggers an experiment configuration load, and our app isn't ready to respond that early in the process.
TextureGroup · Nov 27, 2018 · a255953 · a255953
1 parent f2bc63f
commit a255953
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Showing 4 changed files with 27 additions and 11 deletions.
diff --git a/Source/ASImageNode.mm b/Source/ASImageNode.mm
@@ -433,11 +433,15 @@ + (UIImage *)displayWithParameters:(id<NSObject>)parameter isCancelled:(NS_NOESC
 }
 
 static ASWeakMap<ASImageNodeContentsKey *, UIImage *> *cache = nil;
-// Allocate cacheLock on the heap to prevent destruction at app exit (https://github.com/TextureGroup/Texture/issues/136)
-static auto *cacheLock = new ASDN::Mutex;
 
 + (ASWeakMapEntry *)contentsForkey:(ASImageNodeContentsKey *)key drawParameters:(id)drawParameters isCancelled:(asdisplaynode_iscancelled_block_t)isCancelled
 {
+  static dispatch_once_t onceToken;
+  static ASDN::Mutex *cacheLock = nil;
+  dispatch_once(&onceToken, ^{
+    cacheLock = new ASDN::Mutex();
+  });
+
   {
     ASDN::MutexLocker l(*cacheLock);
     if (!cache) {

diff --git a/Source/ASTextNode2.mm b/Source/ASTextNode2.mm
@@ -54,11 +54,11 @@ @implementation ASTextCacheValue
  * NOTE: Be careful to copy `text` if needed.
  */
 static NS_RETURNS_RETAINED ASTextLayout *ASTextNodeCompatibleLayoutWithContainerAndText(ASTextContainer *container, NSAttributedString *text)  {
-  // Allocate layoutCacheLock on the heap to prevent destruction at app exit (https://github.com/TextureGroup/Texture/issues/136)
-  static auto *layoutCacheLock = new ASDN::Mutex;
-  static NSCache<NSAttributedString *, ASTextCacheValue *> *textLayoutCache;
   static dispatch_once_t onceToken;
+  static ASDN::Mutex *layoutCacheLock;
+  static NSCache<NSAttributedString *, ASTextCacheValue *> *textLayoutCache;
   dispatch_once(&onceToken, ^{
+    layoutCacheLock = new ASDN::Mutex();
     textLayoutCache = [[NSCache alloc] init];
   });
 

diff --git a/Source/Details/ASBasicImageDownloader.mm b/Source/Details/ASBasicImageDownloader.mm
@@ -38,12 +38,20 @@ @interface ASBasicImageDownloaderContext ()
 @implementation ASBasicImageDownloaderContext
 
 static NSMutableDictionary *currentRequests = nil;
-// Allocate currentRequestsLock on the heap to prevent destruction at app exit (https://github.com/TextureGroup/Texture/issues/136)
-static auto *currentRequestsLock = new ASDN::Mutex;
+
++ (ASDN::Mutex *)currentRequestLock
+{
+  static dispatch_once_t onceToken;
+  static ASDN::Mutex *currentRequestsLock;
+  dispatch_once(&onceToken, ^{
+    currentRequestsLock = new ASDN::Mutex();
+  });
+  return currentRequestsLock;
+}
 
 + (ASBasicImageDownloaderContext *)contextForURL:(NSURL *)URL
 {
-  ASDN::MutexLocker l(*currentRequestsLock);
+  ASDN::MutexLocker l(*self.currentRequestLock);
   if (!currentRequests) {
     currentRequests = [[NSMutableDictionary alloc] init];
   }
@@ -57,7 +65,7 @@ + (ASBasicImageDownloaderContext *)contextForURL:(NSURL *)URL
 
 + (void)cancelContextWithURL:(NSURL *)URL
 {
-  ASDN::MutexLocker l(*currentRequestsLock);
+  ASDN::MutexLocker l(*self.currentRequestLock);
   if (currentRequests) {
     [currentRequests removeObjectForKey:URL];
   }

diff --git a/Source/TextKit/ASTextKitContext.mm b/Source/TextKit/ASTextKitContext.mm
@@ -34,9 +34,13 @@ - (instancetype)initWithAttributedString:(NSAttributedString *)attributedString
 
 {
   if (self = [super init]) {
+    static dispatch_once_t onceToken;
+    static ASDN::Mutex *mutex;
+    dispatch_once(&onceToken, ^{
+      mutex = new ASDN::Mutex();
+    });
+
     // Concurrently initialising TextKit components crashes (rdar://18448377) so we use a global lock.
-    // Allocate mutex on the heap to prevent destruction at app exit (https://github.com/TextureGroup/Texture/issues/136)
-    static auto *mutex = new ASDN::Mutex;
     ASDN::MutexLocker l(*mutex);
 
     __instanceLock__ = std::make_shared<ASDN::Mutex>();