Replace cancellation checks with yield

app/src/main/java/chat/rocket/android/chatrooms/viewmodel/ChatRoomsViewModel.kt

@@ -20,12 +20,8 @@ import chat.rocket.core.model.SpotlightResult
 import com.shopify.livedataktx.distinct
 import com.shopify.livedataktx.map
 import com.shopify.livedataktx.nonNull
+import kotlinx.coroutines.experimental.*
 import kotlinx.coroutines.experimental.android.UI
-import kotlinx.coroutines.experimental.delay
-import kotlinx.coroutines.experimental.isActive
-import kotlinx.coroutines.experimental.launch
-import kotlinx.coroutines.experimental.newSingleThreadContext
-import kotlinx.coroutines.experimental.withContext
 import timber.log.Timber
 import java.lang.IllegalArgumentException
 import kotlin.coroutines.experimental.coroutineContext
@@ -53,18 +49,12 @@ class ChatRoomsViewModel(
 
                     // debounce, to not query while the user is writing
                     delay(200)
-                    // TODO - find a better way for cancellation checking
-                    if (!coroutineContext.isActive) return@wrap
-
+                    yield()
                     val rooms = repository.search(string).let { mapper.map(it, showLastMessage = this.showLastMessage) }
                     data.postValue(rooms.toMutableList() + LoadingItemHolder())
-
-
-                    if (!coroutineContext.isActive) return@wrap
-
+                    yield()
                     val spotlight = spotlight(query.query)?.let { mapper.map(it, showLastMessage = this.showLastMessage) }
-                    if (!coroutineContext.isActive) return@wrap
-
+                    yield()
                     spotlight?.let {
                         data.postValue(rooms.toMutableList() + spotlight)
                     }.ifNull {

app/src/main/java/chat/rocket/android/server/infraestructure/ConnectionManager.kt

@@ -295,7 +295,7 @@ class ConnectionManager(
             val batch = ArrayList<T>(maxSize)
             var deadline = 0L // deadline for sending this batch to callback block
 
-            while(true) {
+            while(isActive) {
                 // when deadline is reached or size is exceeded, pass the batch to the callback block
                 val remainingTime = deadline - System.currentTimeMillis()
                 if (batch.isNotEmpty() && remainingTime <= 0 || batch.size >= maxSize) {
@@ -317,8 +317,6 @@ class ConnectionManager(
                     // when timeout is reached just finish select, note: no timeout when batch is empty
                     if (batch.isNotEmpty()) onTimeout(remainingTime.orZero()) {}
                 }
-
-                if (!isActive) break
             }
         }
     }

app/src/main/java/chat/rocket/android/util/IO.kt

@@ -5,6 +5,7 @@ import chat.rocket.common.RocketChatNetworkErrorException
 import kotlinx.coroutines.experimental.TimeoutCancellationException
 import kotlinx.coroutines.experimental.delay
 import kotlinx.coroutines.experimental.isActive
+import kotlinx.coroutines.experimental.yield
 import timber.log.Timber
 import kotlin.coroutines.experimental.coroutineContext
 
@@ -48,19 +49,15 @@ suspend fun <T> retryDB(
 {
     var currentDelay = initialDelay
     repeat(times - 1) { currentTry ->
-        if (!coroutineContext.isActive) throw TimeoutCancellationException("job canceled")
         try {
             return block()
         } catch (e: SQLiteDatabaseLockedException) {
             Timber.d(e, "failed call($currentTry): $description")
             e.printStackTrace()
         }
-
-        if (!coroutineContext.isActive) throw TimeoutCancellationException("job canceled")
         delay(currentDelay)
         currentDelay = (currentDelay * factor).toLong().coerceAtMost(maxDelay)
     }
-
-    if (!coroutineContext.isActive) throw TimeoutCancellationException("job canceled")
+    yield()
     return block() // last attempt
 }
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