Swift Realm Write method is Sync or Async Thread

Question

I am using Realm in My project, and I want to know whether the realm.write() method is synchronous or not. My example is here:

 let realm = try! Realm()
    try! realm.write {
        realm.delete(message)
    }
    realm.invalidate()

In the above example, I am deleting a realm object and outside braces I am writing invalidate()

Here is my confusion:

1. If write() is synchronous, then invalidate() is ok

2. And if Async than before write invalidate will call, and realm will release but operation is running in background

Thanks

Answer 1

Realm.write is synchronous. It just calls realm.beginWrite()/realm.commitWrite() with some error handling:

public func write(_ block: (() throws -> Void)) throws {
    beginWrite()
    do {
        try block()
    } catch let error {
        if isInWriteTransaction { cancelWrite() }
        throw error
    }
    if isInWriteTransaction { try commitWrite() }
}