Fix the current caches manager, does not apply the SDImageCache.sharedImageCache. Fix the thread safe issue of caches manager.

Update the test cases and documents about this behavior.

SDWebImage/SDImageCachesManager.h

@@ -19,7 +19,7 @@ typedef NS_ENUM(NSUInteger, SDImageCachesManagerOperationPolicy) {
 @interface SDImageCachesManager : NSObject <SDImageCache>
 
 /**
- Returns the global shared caches manager instance.
+ Returns the global shared caches manager instance. By default we will set [`SDImageCache.sharedImageCache`] into the caches array.
  */
 @property (nonatomic, class, readonly, nonnull) SDImageCachesManager *sharedManager;
 

SDWebImage/SDImageCachesManager.m

@@ -8,6 +8,13 @@
 
 #import "SDImageCachesManager.h"
 #import "SDImageCachesManagerOperation.h"
+#import "SDImageCache.h"
+
+@interface SDImageCachesManager ()
+
+@property (nonatomic, strong, nonnull) dispatch_semaphore_t cachesLock;
+
+@end
 
 @implementation SDImageCachesManager
 
@@ -28,6 +35,9 @@
         self.removeOperationPolicy = SDImageCachesManagerOperationPolicyConcurrent;
         self.containsOperationPolicy = SDImageCachesManagerOperationPolicySerial;
         self.clearOperationPolicy = SDImageCachesManagerOperationPolicyConcurrent;
+        // initialize with default image caches
+        self.caches = @[[SDImageCache sharedImageCache]];
+        self.cachesLock = dispatch_semaphore_create(1);
     }
     return self;
 }
@@ -38,21 +48,25 @@
     if (![cache conformsToProtocol:@protocol(SDImageCache)]) {
         return;
     }
+    SD_LOCK(self.cachesLock);
     NSMutableArray<id<SDImageCache>> *mutableCaches = [self.caches mutableCopy];
     if (!mutableCaches) {
         mutableCaches = [NSMutableArray array];
     }
     [mutableCaches addObject:cache];
     self.caches = [mutableCaches copy];
+    SD_UNLOCK(self.cachesLock);
 }
 
 - (void)removeCache:(id<SDImageCache>)cache {
     if (![cache conformsToProtocol:@protocol(SDImageCache)]) {
         return;
     }
+    SD_LOCK(self.cachesLock);
     NSMutableArray<id<SDImageCache>> *mutableCaches = [self.caches mutableCopy];
     [mutableCaches removeObject:cache];
     self.caches = [mutableCaches copy];
+    SD_UNLOCK(self.cachesLock);
 }
 
 #pragma mark - SDImageCache

SDWebImage/SDImageLoadersManager.h

@@ -10,6 +10,9 @@
 
 @interface SDImageLoadersManager : NSObject <SDImageLoader>
 
+/**
+ Returns the global shared loaders manager instance. By default we will set [`SDWebImageDownloader.sharedDownloader`] into the loaders array.
+ */
 @property (nonatomic, class, readonly, nonnull) SDImageLoadersManager *sharedManager;
 
 /**

Tests/Tests/SDImageCacheTests.m

@@ -27,14 +27,6 @@ static NSString *kTestImageKeyPNG = @"TestImageKey.png";
 
 @implementation SDImageCacheTests
 
-+ (void)setUp {
-    [[SDImageCachesManager sharedManager] addCache:[SDImageCache sharedImageCache]];
-}
-
-+ (void)tearDown {
-    [[SDImageCachesManager sharedManager] removeCache:[SDImageCache sharedImageCache]];
-}
-
 - (void)test01SharedImageCache {
     expect([SDImageCache sharedImageCache]).toNot.beNil();
 }
@@ -452,8 +444,7 @@ static NSString *kTestImageKeyPNG = @"TestImageKey.png";
     SDImageCachesManager *cachesManager = [[SDImageCachesManager alloc] init];
     SDImageCache *cache1 = [[SDImageCache alloc] initWithNamespace:@"cache1"];
     SDImageCache *cache2 = [[SDImageCache alloc] initWithNamespace:@"cache2"];
-    [cachesManager addCache:cache1];
-    [cachesManager addCache:cache2];
+    cachesManager.caches = @[cache1, cache2];
     
     [[NSFileManager defaultManager] removeItemAtPath:cache1.diskCachePath error:nil];
     [[NSFileManager defaultManager] removeItemAtPath:cache2.diskCachePath error:nil];
@@ -502,8 +493,7 @@ static NSString *kTestImageKeyPNG = @"TestImageKey.png";
     SDImageCachesManager *cachesManager = [[SDImageCachesManager alloc] init];
     SDImageCache *cache1 = [[SDImageCache alloc] initWithNamespace:@"cache1"];
     SDImageCache *cache2 = [[SDImageCache alloc] initWithNamespace:@"cache2"];
-    [cachesManager addCache:cache1];
-    [cachesManager addCache:cache2];
+    cachesManager.caches = @[cache1, cache2];
     
     [[NSFileManager defaultManager] removeItemAtPath:cache1.diskCachePath error:nil];
     [[NSFileManager defaultManager] removeItemAtPath:cache2.diskCachePath error:nil];
@@ -543,8 +533,7 @@ static NSString *kTestImageKeyPNG = @"TestImageKey.png";
     SDImageCachesManager *cachesManager = [[SDImageCachesManager alloc] init];
     SDImageCache *cache1 = [[SDImageCache alloc] initWithNamespace:@"cache1"];
     SDImageCache *cache2 = [[SDImageCache alloc] initWithNamespace:@"cache2"];
-    [cachesManager addCache:cache1];
-    [cachesManager addCache:cache2];
+    cachesManager.caches = @[cache1, cache2];
     
     [[NSFileManager defaultManager] removeItemAtPath:cache1.diskCachePath error:nil];
     [[NSFileManager defaultManager] removeItemAtPath:cache2.diskCachePath error:nil];