Add RxJava.

app/build.gradle

@@ -503,6 +503,9 @@ dependencies {
 
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
     implementation "com.fasterxml.jackson.module:jackson-module-kotlin:2.12.0"
+
+    implementation 'io.reactivex.rxjava3:rxandroid:3.0.0'
+    implementation 'io.reactivex.rxjava3:rxkotlin:3.0.1'
 }
 
 dependencyVerification {

app/src/main/java/org/thoughtcrime/securesms/ApplicationContext.java

@@ -86,6 +86,9 @@ import org.whispersystems.libsignal.logging.SignalProtocolLoggerProvider;
 import java.security.Security;
 import java.util.concurrent.TimeUnit;
 
+import io.reactivex.rxjava3.plugins.RxJavaPlugins;
+import io.reactivex.rxjava3.schedulers.Schedulers;
+
 /**
  * Will be called once when the TextSecure process is created.
  *
@@ -119,10 +122,14 @@ public class ApplicationContext extends MultiDexApplication implements AppForegr
 
     AppStartup.getInstance().addBlocking("security-provider", this::initializeSecurityProvider)
                             .addBlocking("logging", () -> {
-                                initializeLogging();
-                                Log.i(TAG, "onCreate()");
+                              initializeLogging();
+                              Log.i(TAG, "onCreate()");
                             })
                             .addBlocking("crash-handling", this::initializeCrashHandling)
+                            .addBlocking("rx-init", () -> {
+                              RxJavaPlugins.setInitIoSchedulerHandler(schedulerSupplier -> Schedulers.from(SignalExecutors.UNBOUNDED, true, false));
+                              RxJavaPlugins.setInitComputationSchedulerHandler(schedulerSupplier -> Schedulers.from(SignalExecutors.BOUNDED, true, false));
+                            })
                             .addBlocking("eat-db", () -> DatabaseFactory.getInstance(this))
                             .addBlocking("app-dependencies", this::initializeAppDependencies)
                             .addBlocking("notification-channels", () -> NotificationChannels.create(this))

libsignal/service/build.gradle

@@ -30,6 +30,8 @@ dependencies {
     api 'com.squareup.okhttp3:okhttp:3.12.10'
     implementation 'org.threeten:threetenbp:1.3.6'
 
+    api 'io.reactivex.rxjava3:rxjava:3.0.13'
+
     api 'org.signal:zkgroup-java:0.7.0'
 
     testImplementation 'junit:junit:4.12'