Node.js doesn't terminate if Realm.Sync.Adapter is used to open a Realm

[adamchel]

Goals

I am using the Realm.Sync.Adapter API and I am trying to get the Node.js process to finish when I am done using the adapter API. However, if I use the adapter to open any Realm, the Node.js process never finishes executing.

Expected Results

This is my TypeScript code:

import * as Realm from 'realm';

const schemas: Realm.ObjectSchema[] = [
    {
      name: 'TestObj',
      primaryKey: 'pk',
      properties: {
        pk: 'string',
        a: 'string',
        b: 'int',
        c: 'bool',
      }
    }
  ]

let adapter: Realm.Sync.Adapter;
Realm.Sync.User.login(
  'https://my-realm-cloud-instance.us1.cloud.realm.io', 
  Realm.Sync.Credentials.usernamePassword('my_username', 'my_password')
).then(user => {
  adapter = new Realm.Sync.Adapter(
    'adapterData',
    'realms://my-realm-cloud-instance.us1.cloud.realm.io',
    user,
    `.*`,
    (blah: string) => {console.log(blah)}
  )

  // If I comment out these two lines of code, then the process will terminate
  const realm = adapter.realmAtPath('/localTestData', schemas)
  realm.close()

  adapter.close()
  user.logout()

  return;
}).catch(err => {
  console.log(err)
})

I would expect the above compiled Node.js program to finish to completion and terminate.

Actual Results

Instead of terminating, the above program hangs indefinitely. If I sample the process, one of the threads seems to be stuck in realm::util::network::Service::Impl::run() in realm.node.

   2657 Thread_2764463
    + 2657 thread_start  (in libsystem_pthread.dylib) + 13  [0x7fff74c8d40d]
    +   2657 _pthread_start  (in libsystem_pthread.dylib) + 66  [0x7fff74c91249]
    +     2657 _pthread_body  (in libsystem_pthread.dylib) + 126  [0x7fff74c8e2eb]
    +       2657 void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, realm::_impl::SyncClient::SyncClient(std::__1::unique_ptr<realm::util::Logger, std::__1::default_delete<realm::util::Logger> >, realm::sync::Client::ReconnectMode, bool, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&)::'lambda'()> >(void*)  (in realm.node) + 45  [0x10511965d]
    +         2657 realm::util::network::Service::Impl::run()  (in realm.node) + 742  [0x105176446]
    +           2657 realm::util::network::Service::IoReactor::wait_and_advance(std::__1::chrono::time_point<std::__1::chrono::steady_clock, std::__1::chrono::duration<long long, std::__1::ratio<1l, 1000000000l> > >, std::__1::chrono::time_point<std::__1::chrono::steady_clock, std::__1::chrono::duration<long long, std::__1::ratio<1l, 1000000000l> > >, bool&, realm::util::network::Service::OperQueue<realm::util::network::Service::AsyncOper>&)  (in realm.node) + 34  [0x105175a92]
    +             2657 realm::util::network::Service::IoReactor::wait_and_activate(std::__1::chrono::time_point<std::__1::chrono::steady_clock, std::__1::chrono::duration<long long, std::__1::ratio<1l, 1000000000l> > >, std::__1::chrono::time_point<std::__1::chrono::steady_clock, std::__1::chrono::duration<long long, std::__1::ratio<1l, 1000000000l> > >)  (in realm.node) + 89  [0x105175529]
    +               2657 kevent  (in libsystem_kernel.dylib) + 10  [0x7fff74bdb78e]
    2657 Thread_2764464
      2657 start_wqthread  (in libsystem_pthread.dylib) + 13  [0x7fff74c8d3fd]
        2657 _pthread_wqthread  (in libsystem_pthread.dylib) + 634  [0x7fff74c8d6e6]
          2657 __workq_kernreturn  (in libsystem_kernel.dylib) + 10  [0x7fff74bd6bfe]

Steps to Reproduce

Compile the above code sample with this tsconfig.json:

{
  "compilerOptions": {
    "target": "es6",
    "module": "commonjs", 
    "moduleResolution": "node"
  }
}

and run the program. It will not terminate, unless the following two lines are commented out:

  const realm = adapter.realmAtPath('/localTestData', schemas)
  realm.close()

Code Sample

Version of Realm and Tooling

• Realm JS SDK Version: 2.29.2
• Node or React Native: Node v10.15.3
• Client OS & Version: Darwin REDACTED 18.5.0 Darwin Kernel Version 18.5.0: Mon Mar 11 20:40:32 PDT 2019; root:xnu-4903.251.3~3/RELEASE_X86_64 x86_64 (13-inch Macbook Pro 2017, macOS 10.14.4)

[sync-by-unito]

➤ Brian Munkholm commented:

Adapter API removed so no longer relevant.