Revert "Move GTMNSObject+KeyValueObserving over to ARC (#548)"

This reverts commit 27f71f8.

Author: thomasvl

Foundation/BUILD

@@ -32,7 +32,7 @@ objc_library(
         "GTMNSObject+KeyValueObserving.h",
     ],
     copts = ["-IDebugUtils"],
-    srcs = [
+    non_arc_srcs = [
         "GTMNSObject+KeyValueObserving.m",
     ],
     sdk_frameworks = [

Foundation/GTMNSObject+KeyValueObserving.m

@@ -27,7 +27,9 @@
 // See comment in header.
 #import "GTMNSObject+KeyValueObserving.h"
 
+#import <libkern/OSAtomic.h>
 #include <objc/runtime.h>
+#import <stdatomic.h>
 
 #import "GTMDefines.h"
 #import "GTMDebugSelectorValidation.h"
@@ -62,10 +64,11 @@ - (id)dictionaryKeyForObserver:(id)observer
 @end
 
 @interface GTMKeyValueObservingHelper : NSObject {
-  __weak id observer_;
+ @private
+  GTM_WEAK id observer_;
   SEL selector_;
   id userInfo_;
-  __weak id target_;
+  GTM_WEAK id target_;
   NSString* keyPath_;
 }
 
@@ -103,10 +106,10 @@ - (instancetype)initWithObserver:(id)observer
   if((self = [super init])) {
     observer_ = observer;
     selector_ = selector;
-    userInfo_ = userInfo;
+    userInfo_ = [userInfo retain];
 
     target_ = target;
-    keyPath_ = keyPath;
+    keyPath_ = [keyPath retain];
 
     [target addObserver:self
              forKeyPath:keyPath
@@ -128,6 +131,9 @@ - (void)dealloc {
     _GTMDevLog(@"Didn't deregister %@", self);
     [self deregister];
   }
+  [userInfo_ release];
+  [keyPath_ release];
+  [super dealloc];
 }
 
 - (void)observeValueForKeyPath:(NSString *)keyPath
@@ -140,11 +146,8 @@ - (void)observeValueForKeyPath:(NSString *)keyPath
                                                       ofObject:object
                                                       userInfo:userInfo_
                                                         change:change];
-    #pragma clang diagnostic push
-    #pragma clang diagnostic ignored "-Warc-performSelector-leaks"
-    // We are good here because the selector should not return anything.
     [observer_ performSelector:selector_ withObject:notification];
-    #pragma clang diagnostic pop
+    [notification release];
   } else {
     // COV_NF_START
     // There's no way this should ever be called.
@@ -160,20 +163,26 @@ - (void)observeValueForKeyPath:(NSString *)keyPath
 - (void)deregister {
   [target_ removeObserver:self forKeyPath:keyPath_];
   target_ = nil;
-  observer_ = nil;
 }
 
 @end
 
 @implementation GTMKeyValueObservingCenter
 
 + (instancetype)defaultCenter {
-    static dispatch_once_t onceToken;
-    static GTMKeyValueObservingCenter *center;
-    dispatch_once(&onceToken, ^{
-        center = [[self alloc] init];
-    });
-    return center;
+  static _Atomic (GTMKeyValueObservingCenter *)center = nil;
+  if(!center) {
+    // do a bit of clever atomic setting to make this thread safe
+    // if two threads try to set simultaneously, one will fail
+    // and the other will set things up so that the failing thread
+    // gets the shared center
+    GTMKeyValueObservingCenter *newCenter = [[self alloc] init];
+    GTMKeyValueObservingCenter *expected = nil;
+    if (!atomic_compare_exchange_strong(&center, &expected, newCenter)) {
+      [newCenter release];  // COV_NF_LINE no guarantee we'll hit this line
+    }
+  }
+  return center;
 }
 
 - (instancetype)init {
@@ -183,6 +192,14 @@ - (instancetype)init {
   return self;
 }
 
+// COV_NF_START
+// Singletons don't get deallocated
+- (void)dealloc {
+  [observerHelpers_ release];
+  [super dealloc];
+}
+// COV_NF_END
+
 - (id)dictionaryKeyForObserver:(id)observer
                       ofObject:(id)target
                     forKeyPath:(NSString *)keyPath
@@ -223,6 +240,7 @@ - (void)addObserver:(id)observer
     }
     [observerHelpers_ setObject:helper forKey:key];
   }
+  [helper release];
 }
 
 - (void)removeObserver:(id)observer
@@ -320,13 +338,21 @@ - (instancetype)initWithKeyPath:(NSString *)keyPath
                          change:(NSDictionary *)change {
   if ((self = [super init])) {
     keyPath_ = [keyPath copy];
-    object_ = object;
-    userInfo_ = userInfo;
-    change_ = change;
+    object_ = [object retain];
+    userInfo_ = [userInfo retain];
+    change_ = [change retain];
   }
   return self;
 }
 
+- (void)dealloc {
+  [keyPath_ release];
+  [object_ release];
+  [userInfo_ release];
+  [change_ release];
+  [super dealloc];
+}
+
 - (instancetype)copyWithZone:(NSZone *)zone {
   return [[[self class] allocWithZone:zone] initWithKeyPath:keyPath_
                                                    ofObject:object_
@@ -422,41 +448,40 @@ @implementation NSObject (GTMDebugKeyValueObserving)
     _gtmDebugArrayRemoveObserver:fromObjectsAtIndexes:forKeyPath:);
 
 + (void)load {
-  @autoreleasepool {
-
-    NSDictionary *env = [[NSProcessInfo processInfo] environment];
-    id debugKeyValue = [env valueForKey:@"GTMDebugKVO"];
-    BOOL debug = NO;
-    if ([debugKeyValue isKindOfClass:[NSNumber class]]) {
-      debug = [debugKeyValue intValue] != 0 ? YES : NO;
-    } else if ([debugKeyValue isKindOfClass:[NSString class]]) {
-      debug = ([debugKeyValue hasPrefix:@"Y"] || [debugKeyValue hasPrefix:@"T"] ||
-               [debugKeyValue intValue]);
-    }
-    Class cls = Nil;
-    if (debug) {
-      cls = [NSObject class];
-      SwizzleMethodsInClass(cls,
-                            @selector(addObserver:forKeyPath:options:context:),
-                            @selector(_gtmDebugAddObserver:forKeyPath:options:context:));
-      SwizzleMethodsInClass(cls,
-                            @selector(removeObserver:forKeyPath:),
-                            @selector(_gtmDebugRemoveObserver:forKeyPath:));
-      SwizzleMethodsInClass(cls,
-                            @selector(willChangeValueForKey:),
-                            @selector(_gtmDebugWillChangeValueForKey:));
-      SwizzleMethodsInClass(cls,
-                            @selector(didChangeValueForKey:),
-                            @selector(_gtmDebugDidChangeValueForKey:));
-      cls = [NSArray class];
-      SwizzleMethodsInClass(cls,
-                            @selector(addObserver:toObjectsAtIndexes:forKeyPath:options:context:),
-                            @selector(_gtmDebugArrayAddObserver:toObjectsAtIndexes:forKeyPath:options:context:));
-      SwizzleMethodsInClass(cls,
-                            @selector(removeObserver:fromObjectsAtIndexes:forKeyPath:),
-                            @selector(_gtmDebugArrayRemoveObserver:fromObjectsAtIndexes:forKeyPath:));
-    }
+  NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
+  NSDictionary *env = [[NSProcessInfo processInfo] environment];
+  id debugKeyValue = [env valueForKey:@"GTMDebugKVO"];
+  BOOL debug = NO;
+  if ([debugKeyValue isKindOfClass:[NSNumber class]]) {
+    debug = [debugKeyValue intValue] != 0 ? YES : NO;
+  } else if ([debugKeyValue isKindOfClass:[NSString class]]) {
+    debug = ([debugKeyValue hasPrefix:@"Y"] || [debugKeyValue hasPrefix:@"T"] ||
+             [debugKeyValue intValue]);
+  }
+  Class cls = Nil;
+  if (debug) {
+    cls = [NSObject class];
+    SwizzleMethodsInClass(cls,
+        @selector(addObserver:forKeyPath:options:context:),
+        @selector(_gtmDebugAddObserver:forKeyPath:options:context:));
+    SwizzleMethodsInClass(cls,
+        @selector(removeObserver:forKeyPath:),
+        @selector(_gtmDebugRemoveObserver:forKeyPath:));
+    SwizzleMethodsInClass(cls,
+        @selector(willChangeValueForKey:),
+        @selector(_gtmDebugWillChangeValueForKey:));
+    SwizzleMethodsInClass(cls,
+        @selector(didChangeValueForKey:),
+        @selector(_gtmDebugDidChangeValueForKey:));
+    cls = [NSArray class];
+    SwizzleMethodsInClass(cls,
+        @selector(addObserver:toObjectsAtIndexes:forKeyPath:options:context:),
+        @selector(_gtmDebugArrayAddObserver:toObjectsAtIndexes:forKeyPath:options:context:));
+    SwizzleMethodsInClass(cls,
+        @selector(removeObserver:fromObjectsAtIndexes:forKeyPath:),
+        @selector(_gtmDebugArrayRemoveObserver:fromObjectsAtIndexes:forKeyPath:));
   }
+  [pool drain];
 }
 
 - (void)_gtmDebugAddObserver:(NSObject *)observer

Foundation/GTMNSObject+KeyValueObservingTest.m

@@ -33,7 +33,7 @@
 @interface GTMNSObject_KeyValueObservingTest : GTMTestCase  {
   int32_t count_;
   NSMutableDictionary *dict_;
-  NSString *expectedValue_;
+  GTM_WEAK NSString *expectedValue_;
 }
 
 - (void)observeValueChange:(GTMKeyValueChangeNotification *)notification;

GTM.xcodeproj/project.pbxproj

@@ -44,7 +44,7 @@
 		8B5769AB21CD7ACF00D924D3 /* GTMTimeUtilsTest.m in Sources */ = {isa = PBXBuildFile; fileRef = 8B5769A921CD798000D924D3 /* GTMTimeUtilsTest.m */; };
 		8B61FDC00E4CDB8000FF9C21 /* GTMStackTrace.m in Sources */ = {isa = PBXBuildFile; fileRef = 8B61FDBF0E4CDB8000FF9C21 /* GTMStackTrace.m */; };
 		8B6C15930F356E6400E51E5D /* GTMNSObject+KeyValueObserving.h in Headers */ = {isa = PBXBuildFile; fileRef = 8B6C15910F356E6400E51E5D /* GTMNSObject+KeyValueObserving.h */; settings = {ATTRIBUTES = (Public, ); }; };
-		8B6C15940F356E6400E51E5D /* GTMNSObject+KeyValueObserving.m in Sources */ = {isa = PBXBuildFile; fileRef = 8B6C15920F356E6400E51E5D /* GTMNSObject+KeyValueObserving.m */; settings = {COMPILER_FLAGS = "-fobjc-arc"; }; };
+		8B6C15940F356E6400E51E5D /* GTMNSObject+KeyValueObserving.m in Sources */ = {isa = PBXBuildFile; fileRef = 8B6C15920F356E6400E51E5D /* GTMNSObject+KeyValueObserving.m */; };
 		8B6F4B630E8856CA00425D9F /* GTMDebugThreadValidation.h in Headers */ = {isa = PBXBuildFile; fileRef = 8B6F4B610E8856CA00425D9F /* GTMDebugThreadValidation.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		8B6F4B640E8856CA00425D9F /* GTMDebugThreadValidation.m in Sources */ = {isa = PBXBuildFile; fileRef = 8B6F4B620E8856CA00425D9F /* GTMDebugThreadValidation.m */; };
 		8B7DCBA50DFF0EFF0017E983 /* GoogleToolboxForMac.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = F42E086D0D199A5B00D5DDE0 /* GoogleToolboxForMac.framework */; };

GTMiPhone.xcodeproj/project.pbxproj

@@ -21,7 +21,7 @@
 		8B82CF081D9C1C3B007182AA /* GTMNSData+zlib.m in Sources */ = {isa = PBXBuildFile; fileRef = 8BC0477F0DAE928A00C2D1CA /* GTMNSData+zlib.m */; };
 		8B82CF0A1D9C1C3B007182AA /* GTMNSFileManager+Path.m in Sources */ = {isa = PBXBuildFile; fileRef = 8BC047850DAE928A00C2D1CA /* GTMNSFileManager+Path.m */; };
 		8B82CF0B1D9C1C3B007182AA /* GTMNSFileHandle+UniqueName.m in Sources */ = {isa = PBXBuildFile; fileRef = 8B2908B011F8E7070064F50F /* GTMNSFileHandle+UniqueName.m */; };
-		8B82CF0D1D9C1C3B007182AA /* GTMNSObject+KeyValueObserving.m in Sources */ = {isa = PBXBuildFile; fileRef = 8B6C18720F3769D200E51E5D /* GTMNSObject+KeyValueObserving.m */; settings = {COMPILER_FLAGS = "-fobjc-arc"; }; };
+		8B82CF0D1D9C1C3B007182AA /* GTMNSObject+KeyValueObserving.m in Sources */ = {isa = PBXBuildFile; fileRef = 8B6C18720F3769D200E51E5D /* GTMNSObject+KeyValueObserving.m */; };
 		8B82CF0F1D9C1C3B007182AA /* GTMNSString+HTML.m in Sources */ = {isa = PBXBuildFile; fileRef = 8BC047880DAE928A00C2D1CA /* GTMNSString+HTML.m */; };
 		8B82CF111D9C1C3B007182AA /* GTMNSString+XML.m in Sources */ = {isa = PBXBuildFile; fileRef = 8BC0478B0DAE928A00C2D1CA /* GTMNSString+XML.m */; };
 		8B82CF121D9C1C3B007182AA /* GTMNSThread+Blocks.m in Sources */ = {isa = PBXBuildFile; fileRef = 8B6FF392151A664600B0642B /* GTMNSThread+Blocks.m */; };
@@ -64,16 +64,6 @@
 		F4A1EEA52B62D38F008B2FC1 /* PrivacyInfo.xcprivacy in Resources */ = {isa = PBXBuildFile; fileRef = F4A1EEA12B62D338008B2FC1 /* PrivacyInfo.xcprivacy */; };
 /* End PBXBuildFile section */
 
-/* Begin PBXContainerItemProxy section */
-		8BFA30492E562C740037F469 /* PBXContainerItemProxy */ = {
-			isa = PBXContainerItemProxy;
-			containerPortal = 29B97313FDCFA39411CA2CEA /* Project object */;
-			proxyType = 1;
-			remoteGlobalIDString = 8B82CEF51D9C17DE007182AA;
-			remoteInfo = GTM;
-		};
-/* End PBXContainerItemProxy section */
-
 /* Begin PBXCopyFilesBuildPhase section */
 		8B82CEF41D9C17DE007182AA /* CopyFiles */ = {
 			isa = PBXCopyFilesBuildPhase;
@@ -472,7 +462,6 @@
 			buildRules = (
 			);
 			dependencies = (
-				8BFA304A2E562C740037F469 /* PBXTargetDependency */,
 			);
 			name = GTMTests;
 			productName = GTMTests;
@@ -604,14 +593,6 @@
 		};
 /* End PBXSourcesBuildPhase section */
 
-/* Begin PBXTargetDependency section */
-		8BFA304A2E562C740037F469 /* PBXTargetDependency */ = {
-			isa = PBXTargetDependency;
-			target = 8B82CEF51D9C17DE007182AA /* GTM */;
-			targetProxy = 8BFA30492E562C740037F469 /* PBXContainerItemProxy */;
-		};
-/* End PBXTargetDependency section */
-
 /* Begin XCBuildConfiguration section */
 		8B82CEFD1D9C17DE007182AA /* Debug */ = {
 			isa = XCBuildConfiguration;

GoogleToolboxForMac.podspec

@@ -69,8 +69,6 @@ Pod::Spec.new do |s|
   s.subspec 'KVO' do |sp|
     sp.source_files =
         'Foundation/GTMNSObject+KeyValueObserving.{h,m}'
-    sp.requires_arc = 
-        'Foundation/GTMNSObject+KeyValueObserving.{h,m}'
     sp.dependency 'GoogleToolboxForMac/Core', "#{s.version}"
     sp.dependency 'GoogleToolboxForMac/DebugUtils', "#{s.version}"
   end