Create a holder

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/DefaultSession.kt

@@ -84,6 +84,7 @@ import kotlin.coroutines.CoroutineContext
 @SessionScope
 internal class DefaultSession @Inject constructor(
         override val sessionParams: SessionParams,
+        private val sessionCoroutineScopeHolder: SessionCoroutineScopeHolder,
         private val workManagerProvider: WorkManagerProvider,
         private val globalErrorHandler: GlobalErrorHandler,
         @SessionId
@@ -161,13 +162,11 @@ internal class DefaultSession @Inject constructor(
     override val isOpenable: Boolean
         get() = sessionParamsStore.get(sessionId)?.isTokenValid ?: false
 
-    private var sessionScope: CoroutineScope? = null
-
     @MainThread
     override fun open() {
         assert(!isOpen)
         isOpen = true
-        sessionScope = CoroutineScope(SupervisorJob())
+        sessionCoroutineScopeHolder.start()
         cryptoService.get().ensureDevice()
         uiHandler.post {
             lifecycleObservers.forEach { it.onSessionStarted() }
@@ -208,8 +207,7 @@ internal class DefaultSession @Inject constructor(
 
     override fun close() {
         assert(isOpen)
-        sessionScope?.coroutineContext?.cancelChildren(CancellationException("Closing session"))
-        sessionScope = null
+        sessionCoroutineScopeHolder.stop()
         stopSync()
         // timelineEventDecryptor.destroy()
         uiHandler.post {
@@ -315,7 +313,7 @@ internal class DefaultSession @Inject constructor(
 
     override fun launch(context: CoroutineContext,
                         block: suspend () -> Unit) {
-        sessionScope?.launch(context) {
+        sessionCoroutineScopeHolder.scope?.launch(context) {
             block()
         }
     }

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/SessionCoroutineScopeHolder.kt

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2021 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.android.sdk.internal.session
+
+import kotlinx.coroutines.CancellationException
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.cancelChildren
+
+@SessionScope
+internal class SessionCoroutineScopeHolder {
+
+    var scope: CoroutineScope? = null
+        private set
+
+    fun start() {
+        scope = CoroutineScope(SupervisorJob())
+    }
+
+    fun stop() {
+        scope?.coroutineContext?.cancelChildren(CancellationException("Closing session"))
+        scope = null
+    }
+}