IssueTracker

Please provide a sample app that reproduces your issue.
We have tests around this so would like to know what use case is broken so that we can fix it with a test.

I've already figured it out the problem: I use two instances of RoomDatabase when querying database and updating database.

Wait, are you the same person who created the bug report?

FYI Room should support multiple database connections but there is a missing piece right now about making them talk to each other. Hopefully we'll support this (especially important for multi-proces suse case).

Yes, I am. Sorry, I commented and forgot login the previous Google account.

Here's my project to test

related: b/63325506

we can probably tie this to WAL support.

So the title of this bug should be changed to "support multiple instances of RoomDatabase"?

When support this? i face the same problem, it multiple query and insert, it'll block

hopefully we'll have this in 2.1 . What is your use case, are you accessing the same database from different processes or are you creating 2 instance of the same RoomDatabase in the same process?

Create one instance of RoomDatabase, and use LiveData paging query the datas and when querying, i also use the db connect insert the data, the query always wait the insert end and return

BTW, other thread insert the data, or update the data

if you are in the same process, don't use multiple RoomDatabase instances.

Why the LiveData been blocked? the query always waiting for the insert end and return

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

commit 41bbdfb46058e7ef3ea6aa21ac8d7a3c7642fa1d
Author: Yuichi Araki <yaraki@google.com>
Date:   Wed May 23 17:38:58 2018

    Multi-instance invalidation
   
    Developers can now sync observers for InvalidationTracker and LiveData
    between multiple RoomDatabase instances by
    RoomDatabase.Builder.enableMultiInstanceInvalidation(). This can also be
    used for database instances in other processes. All the instances have
    to be using the same database file.
   
    When multi-instance invalidation is turned on, all the tables are
    observed by an instance of MultiInstanceInvalidationClient, and
    invalidation detected in one instance is broadcast to other instances by
    remote procedure call.
   
    Test: MultiInstanceInvalidationTest
    Bug: 62334005
    Bug: 80464228
    Change-Id: I76033c5ac543ddaef735be06f828b7d7d607883a

M       room/integration-tests/testapp/build.gradle
A       room/integration-tests/testapp/src/androidTest/java/androidx/room/integration/testapp/test/MultiInstanceInvalidationTest.java
M       room/integration-tests/testapp/src/main/AndroidManifest.xml
A       room/integration-tests/testapp/src/main/aidl/androidx/room/integration/testapp/ISampleDatabaseService.aidl
A       room/integration-tests/testapp/src/main/java/androidx/room/integration/testapp/SampleDatabaseService.java
M       room/integration-tests/testapp/src/main/java/androidx/room/integration/testapp/database/CustomerDao.java
A       room/integration-tests/testapp/src/main/java/androidx/room/integration/testapp/database/Product.java
A       room/integration-tests/testapp/src/main/java/androidx/room/integration/testapp/database/ProductDao.java
M       room/integration-tests/testapp/src/main/java/androidx/room/integration/testapp/database/SampleDatabase.java
M       room/runtime/api/current.txt
M       room/runtime/src/main/AndroidManifest.xml
A       room/runtime/src/main/aidl/androidx/room/IMultiInstanceInvalidationCallback.aidl
A       room/runtime/src/main/aidl/androidx/room/IMultiInstanceInvalidationService.aidl
M       room/runtime/src/main/java/androidx/room/DatabaseConfiguration.java
M       room/runtime/src/main/java/androidx/room/InvalidationTracker.java
A       room/runtime/src/main/java/androidx/room/MultiInstanceInvalidationClient.java
A       room/runtime/src/main/java/androidx/room/MultiInstanceInvalidationService.java
M       room/runtime/src/main/java/androidx/room/RoomDatabase.java
M       room/testing/src/main/java/androidx/room/testing/MigrationTestHelper.java

https://android-review.googlesource.com/720919
https://goto.google.com/android-sha1/41bbdfb46058e7ef3ea6aa21ac8d7a3c7642fa1d