CoreData_Deadlock_1.swift

import CoreData

let c1 = NSManagedObjectContext(concurrencyType: .privateQueueConcurrencyType)
let c2 = NSManagedObjectContext(concurrencyType: .privateQueueConcurrencyType)

// 문제 없음
c1.performAndWait {
    c2.performAndWait {
        c1.performAndWait {
            
        }
    }
    
    c2.performAndWait {
        
    }
}


// 문제됨
c1.performAndWait {
    c2.perform {
        c1.performAndWait {
            
        }
    }
    
    c2.performAndWait {
        
    }
}