Objective c NSBlockOperation上的CHCSV导入程序内存问题

我使用的是XCode 8.2，Objective-C，OSX（不是iOS），支持ARC

我正在使用DaveDelongs CHCSV解析器在自定义NSBlockOperation中导入一个大型CSV文件。我的问题是：操作完成后内存没有释放。即使我不保存解析的NSArray*也会发生同样的情况

以下是代码的基本部分：

SHImportDataOperation.m（自定义NSBlockOperation）

编辑1:

进一步测试后，我可以确认NSBlockOperation已成功执行并从内存中删除

// CHCSV parser delegate
@interface Delegate : NSObject <CHCSVParserDelegate>

    @property (readonly) NSArray *lines; // <-- parsing result is stored here
    @property (readonly) NSString *errorMessage;
    @property unsigned long long filesize;
    @property SHGlobalAppData* global;

@end

@implementation SHImportDataOperation
    @synthesize finished  = _finished;
    @synthesize executing = _executing;

- (void)main
{
    // ###############################
    // UI stuff
    dispatch_async(dispatch_get_main_queue(), ^{

        // Hide controls
        [_global.dataFile setFileDropped:NO]; // _global.dataFile is an NSObject with relevant fileInformation
    });

    // ###############################
    // Import CSV
        if (![self importCSV:_global.dataFile]) 
        {                
            [self breakImportData]; // Cleanup
            return;
        }
    }

    // ###############################
    // Finishing Import Data

    // UI stuff
    dispatch_async(dispatch_get_main_queue(), ^{

        // Show controls
        [_global.dataFile setFileDropped:YES];

        // Show OK
        [_global.dataFile setImported:YES];

        // Cleanup
        [self finishOperation];
    });
}

// ################################################
// cleanup
- (void)finishOperation
{
    [self willChangeValueForKey:@"isFinished"];
    [self willChangeValueForKey:@"isExecuting"];
    _executing = NO;
    _finished = YES;
    [self didChangeValueForKey:@"isExecuting"];
    [self didChangeValueForKey:@"isFinished"];
}

// ################################################
- (BOOL)importCSV:(SHDataModelData *)dataFile
{
    encoding = NSMacOSRomanStringEncoding;        
    NSString* delimiter = @",";
    unichar delimiterUnichar = [delimiter characterAtIndex:0];


    // ###############################
    NSInputStream* stream = [NSInputStream inputStreamWithFileAtPath:dataFile.filePath];
    CHCSVParser* p = [[CHCSVParser alloc] initWithInputStream:stream usedEncoding:&encoding delimiter:delimiterUnichar];

    Delegate * d = [[Delegate alloc] init];
    [d setGlobal:_global]; // Reference needed for UI progress bar

    [p setDelegate:d];
    [p setFilepath:dataFile.filePath];      
    [p parse];

    //NSLog(@"Result: %@",d.lines);

    // Save imported data
    //[dataFile setImportData:d.lines]; // Even if not saved, memory is not free'd after operation

    // Even if i nil everything, memory is not freed.
    [d setGlobal:nil];
    [p setDelegate:nil];
    d = nil;
    p = nil;

    return true;
}

NSOperationQueue* operationImportQueue = [NSOperationQueue new];

SHImportLayoutOperation *importLayoutOperation = [[SHImportLayoutOperation alloc] init];
[importLayoutOperation setGlobal:[self theAppDataObject]];

SHImportDataOperation *importDataOperation = [[SHImportDataOperation alloc] init];
[importDataOperation setGlobal:[self theAppDataObject]];

NSBlockOperation *importDoneCompletionOperation = [NSBlockOperation blockOperationWithBlock:^{
    [self continueWithStuff];                
    }];

[importDoneCompletionOperation addDependency:importDataOperation];
[importDoneCompletionOperation addDependency:importLayoutOperation];

[operationImportQueue addOperation:importDoneCompletionOperation];
[operationImportQueue addOperation:importDataOperation];
[operationImportQueue addOperation:importLayoutOperation];