IssueTracker

+1, but Deferred does not solve the Observer problem that Rx and LiveData do, so I guess Google should implement Channels instead of LiveData which is actually a Kotlin Coroutine counterpart. Looking forward to this as I've decided not to use RxJava in most of future projects due to Kotlin Coroutines..

Project: platform/frameworks/support
Branch: androidx-master-dev

commit e78cceffeac28f0028342990c1391c640edf453c
Author: Daniel Santiago Rivera <danysantiago@google.com>
Date:   Wed Nov 28 12:40:24 2018

    Room Support for Coroutines
   
    This change allows users to define suspend functions in DAOs with
    @Query, @Insert, @Update and @Delete. The new artifact room-coroutine
    defines a helper classes for supporting the feature.
   
    Bug: 69474692
    Test: ./gradlew room:integration-tests:kotlintestapp:cC
    Change-Id: Id73a6b845df3f21f99d14cb6980130dcf3885c81

M       buildSrc/src/main/kotlin/androidx/build/PublishDocsRules.kt
A       room/compiler/src/main/kotlin/androidx/room/ext/KotlinMetadataElement.kt
D       room/compiler/src/main/kotlin/androidx/room/ext/KotlinMetadataProcessor.kt
M       room/compiler/src/main/kotlin/androidx/room/ext/element_ext.kt
M       room/compiler/src/main/kotlin/androidx/room/ext/javapoet_ext.kt
M       room/compiler/src/main/kotlin/androidx/room/processor/DeletionMethodProcessor.kt
M       room/compiler/src/main/kotlin/androidx/room/processor/InsertionMethodProcessor.kt
A       room/compiler/src/main/kotlin/androidx/room/processor/MethodProcessorDelegate.kt
M       room/compiler/src/main/kotlin/androidx/room/processor/PojoProcessor.kt
M       room/compiler/src/main/kotlin/androidx/room/processor/ProcessorErrors.kt
M       room/compiler/src/main/kotlin/androidx/room/processor/QueryMethodProcessor.kt
M       room/compiler/src/main/kotlin/androidx/room/processor/RawQueryMethodProcessor.kt
M       room/compiler/src/main/kotlin/androidx/room/processor/ShortcutMethodProcessor.kt
M       room/compiler/src/main/kotlin/androidx/room/processor/UpdateMethodProcessor.kt
A       room/compiler/src/main/kotlin/androidx/room/solver/query/result/CoroutineResultBinder.kt
M       room/compiler/src/main/kotlin/androidx/room/solver/query/result/PojoRowAdapter.kt
A       room/compiler/src/main/kotlin/androidx/room/solver/shortcut/binder/CoroutineDeleteOrUpdateMethodBinder.kt
A       room/compiler/src/main/kotlin/androidx/room/solver/shortcut/binder/CoroutineInsertMethodBinder.kt
M       room/compiler/src/main/kotlin/androidx/room/solver/shortcut/result/DeleteOrUpdateMethodAdapter.kt
M       room/compiler/src/main/kotlin/androidx/room/solver/shortcut/result/InsertMethodAdapter.kt
M       room/compiler/src/main/kotlin/androidx/room/vo/RelationCollector.kt
M       room/compiler/src/test/kotlin/androidx/room/processor/QueryMethodProcessorTest.kt
A       room/coroutines/build.gradle
A       room/coroutines/src/main/AndroidManifest.xml
A       room/coroutines/src/main/java/androidx/room/CoroutinesRoom.kt
M       room/integration-tests/kotlintestapp/build.gradle
M       room/integration-tests/kotlintestapp/src/androidTest/java/androidx/room/integration/kotlintestapp/dao/BooksDao.kt
M       room/integration-tests/kotlintestapp/src/androidTest/java/androidx/room/integration/kotlintestapp/test/BooksDaoTest.kt
A       room/integration-tests/kotlintestapp/src/androidTest/java/androidx/room/integration/kotlintestapp/test/SuspendRoomDispatcherTest.kt
M       settings.gradle

https://android-review.googlesource.com/833705
https://goto.google.com/android-sha1/e78cceffeac28f0028342990c1391c640edf453c

So do you support any Coroutine "observables" like channels? Or these are just one-off suspending calls?

For now we'll be just supporting one-off suspend functions in Room 2.1.0-alpha03. Coroutines stream functionality with channels is still a work in progress.

Relating to the original request, how about allowing a return type of Deferred<LiveData<T>> which suspends until LiveData<T>'s value has been set the first time?

I just tested out Room 2.1.0-alpha03 and added suspend to all of my functions.... there appears to be an issue with functions that use @Query() and UPDATE and DELETE queries.  Examples:

Code Example 1:
    @Query("DELETE FROM individual")
    suspend fun deleteAll()
Error:
    Deletion methods must either return void or return int (the number of deleted rows).

Code Example 2:
    @Query("UPDATE individual SET firstName = :firstName WHERE id = :id")
    suspend fun updateFirstName(id: Long, firstName: String)
Error:
    Not sure how to convert a Cursor to this method's return type (kotlin.Unit).