Thread safe for NSMutableArray

PMThreadSafeMutableArray.m

//
//  PMThreadSafeMutableArray.m
//
//  Created by nhatlee on 1/19/18.
//  Copyright © 2018 nhatlee. All rights reserved.
//

#import "PMThreadSafeMutableArray.h"
#import <libkern/OSAtomic.h>

#define LOCKED(...) OSSpinLockLock(&_lock);\
__VA_ARGS__;\
OSSpinLockUnlock(&_lock);

@implementation PMThreadSafeMutableArray {
    OSSpinLock _lock;
    NSMutableArray *_array;
}

#pragma mark - NSObject
- (id)init {
    return [self initWithCapacity:0];
}

-(id)initWithArray:(NSArray *)array {
    if(self = [self initWithCapacity:array.count]) {
        [array enumerateObjectsUsingBlock:^(id  _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
            _array[idx] = obj;
        }];
    }
    return self;
}

-(id)initWithCapacity:(NSUInteger)numItems {
    if(self = [super init]) {
        _array = [[NSMutableArray alloc] initWithCapacity:numItems];
        _lock = OS_SPINLOCK_INIT;
    }
    return self;
}

#pragma mark - NSMutableArray
-(void)addObject:(id)anObject {
    LOCKED([_array addObject: anObject]);
}

-(void)addObjectsFromArray:(NSArray *)otherArray {
    LOCKED([_array addObjectsFromArray:otherArray]);
}

-(void)replaceObjectAtIndex:(NSUInteger)index withObject:(id)anObject {
    LOCKED([_array replaceObjectAtIndex:index withObject:anObject]);
}

-(void)replaceObjectsAtIndexes:(NSIndexSet *)indexes withObjects:(NSArray *)objects {
    LOCKED([_array replaceObjectsAtIndexes:indexes withObjects:objects]);
}

-(void)removeObject:(id)anObject {
    LOCKED([_array removeObject:anObject]);
}

-(void)removeAllObjects {
    LOCKED([_array removeAllObjects]);
}

-(NSUInteger)count {
    LOCKED(NSUInteger count = _array.count);
    return count;
}

-(id)objectAtIndex:(NSUInteger)index {
    LOCKED(id obj = _array[index]);
    return obj;
}

-(NSUInteger)indexOfObject:(id)anObject {
    LOCKED(NSUInteger idx = [_array indexOfObject:anObject]);
    return idx;
}

-(id)copyWithZone:(NSZone *)zone {
    return [self mutableCopyWithZone:zone];
}

-(id)mutableCopyWithZone:(NSZone *)zone {
    LOCKED(id copiedArray = [[self.class allocWithZone:zone] initWithArray:_array]);
    return copiedArray;
}

-(NSUInteger)countByEnumeratingWithState:(NSFastEnumerationState *)state objects:(id  _Nullable __unsafe_unretained [])buffer count:(NSUInteger)len {
    LOCKED(NSUInteger count = [[_array copy] countByEnumeratingWithState:state objects:buffer count:len]);
    return count;
}

-(void)performLockWithArray:(void (^)(NSArray *anArray))block {
    if(block) LOCKED(block(_array));
}

-(BOOL)isEqual:(id)object {
    if (object == self) return YES;
    if([object isKindOfClass:[PMThreadSafeMutableArray class]]) {
        PMThreadSafeMutableArray *other = object;
        __block BOOL isEqual = NO;
        [other performLockWithArray:^(NSArray *anArray) {
            [self performLockWithArray:^(NSArray *otherArray) {
                isEqual = [anArray isEqual:otherArray];
            }];
        }];
        return isEqual;
    }
    return NO;
}

@end