feat: SDK-4176: gate background threading behind remote feature flag (#2595)

Co-authored-by: AR Abdul Azeez <abdul@onesignal.com>

Author: abdulraqeeb33

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/common/threading/ThreadUtils.kt

@@ -1,9 +1,15 @@
+@file:Suppress("GlobalCoroutineUsage")
+
 package com.onesignal.common.threading
 
 import com.onesignal.debug.internal.logging.Logging
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.Job
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.runBlocking
 import kotlinx.coroutines.withContext
+import kotlin.concurrent.thread
 
 /**
  * Modernized ThreadUtils that leverages OneSignalDispatchers for better thread management.
@@ -24,8 +30,27 @@ import kotlinx.coroutines.withContext
  *
  */
 fun suspendifyOnMain(block: suspend () -> Unit) {
-    OneSignalDispatchers.launchOnIO {
-        withContext(Dispatchers.Main) { block() }
+    if (ThreadingMode.useBackgroundThreading) {
+        OneSignalDispatchers.launchOnIO {
+            try {
+                withContext(Dispatchers.Main) { block() }
+            } catch (e: Exception) {
+                Logging.error("Exception in suspendifyOnMain", e)
+            }
+        }
+        return
+    }
+
+    thread {
+        try {
+            runBlocking {
+                withContext(Dispatchers.Main) {
+                    block()
+                }
+            }
+        } catch (e: Exception) {
+            Logging.error("Exception on thread with switch to main", e)
+        }
     }
 }
 
@@ -86,24 +111,36 @@ fun suspendifyWithCompletion(
     block: suspend () -> Unit,
     onComplete: (() -> Unit)? = null,
 ) {
-    if (useIO) {
-        OneSignalDispatchers.launchOnIO {
-            try {
-                block()
-                onComplete?.invoke()
-            } catch (e: Exception) {
-                Logging.error("Exception in suspendifyWithCompletion", e)
+    if (ThreadingMode.useBackgroundThreading) {
+        if (useIO) {
+            OneSignalDispatchers.launchOnIO {
+                try {
+                    block()
+                    onComplete?.invoke()
+                } catch (e: Exception) {
+                    Logging.error("Exception in suspendifyWithCompletion", e)
+                }
             }
-        }
-    } else {
-        OneSignalDispatchers.launchOnDefault {
-            try {
-                block()
-                onComplete?.invoke()
-            } catch (e: Exception) {
-                Logging.error("Exception in suspendifyWithCompletion", e)
+        } else {
+            OneSignalDispatchers.launchOnDefault {
+                try {
+                    block()
+                    onComplete?.invoke()
+                } catch (e: Exception) {
+                    Logging.error("Exception in suspendifyWithCompletion", e)
+                }
             }
         }
+        return
+    }
+
+    GlobalScope.launch(if (useIO) Dispatchers.IO else Dispatchers.Default) {
+        try {
+            block()
+            onComplete?.invoke()
+        } catch (e: Exception) {
+            Logging.error("Exception in suspendifyWithCompletion", e)
+        }
     }
 }
 
@@ -122,26 +159,39 @@ fun suspendifyWithErrorHandling(
     onError: ((Exception) -> Unit)? = null,
     onComplete: (() -> Unit)? = null,
 ) {
-    if (useIO) {
-        OneSignalDispatchers.launchOnIO {
-            try {
-                block()
-                onComplete?.invoke()
-            } catch (e: Exception) {
-                Logging.error("Exception in suspendifyWithErrorHandling", e)
-                onError?.invoke(e)
+    if (ThreadingMode.useBackgroundThreading) {
+        if (useIO) {
+            OneSignalDispatchers.launchOnIO {
+                try {
+                    block()
+                    onComplete?.invoke()
+                } catch (e: Exception) {
+                    Logging.error("Exception in suspendifyWithErrorHandling", e)
+                    onError?.invoke(e)
+                }
             }
-        }
-    } else {
-        OneSignalDispatchers.launchOnDefault {
-            try {
-                block()
-                onComplete?.invoke()
-            } catch (e: Exception) {
-                Logging.error("Exception in suspendifyWithErrorHandling", e)
-                onError?.invoke(e)
+        } else {
+            OneSignalDispatchers.launchOnDefault {
+                try {
+                    block()
+                    onComplete?.invoke()
+                } catch (e: Exception) {
+                    Logging.error("Exception in suspendifyWithErrorHandling", e)
+                    onError?.invoke(e)
+                }
             }
         }
+        return
+    }
+
+    GlobalScope.launch(if (useIO) Dispatchers.IO else Dispatchers.Default) {
+        try {
+            block()
+            onComplete?.invoke()
+        } catch (e: Exception) {
+            Logging.error("Exception in suspendifyWithErrorHandling", e)
+            onError?.invoke(e)
+        }
     }
 }
 
@@ -153,7 +203,23 @@ fun suspendifyWithErrorHandling(
  * @return Job that can be used to wait for completion with .join()
  */
 fun launchOnIO(block: suspend () -> Unit): Job {
-    return OneSignalDispatchers.launchOnIO(block)
+    return if (ThreadingMode.useBackgroundThreading) {
+        OneSignalDispatchers.launchOnIO {
+            try {
+                block()
+            } catch (e: Exception) {
+                Logging.error("Exception in launchOnIO", e)
+            }
+        }
+    } else {
+        GlobalScope.launch(Dispatchers.IO) {
+            try {
+                block()
+            } catch (e: Exception) {
+                Logging.error("Exception in launchOnIO", e)
+            }
+        }
+    }
 }
 
 /**
@@ -164,5 +230,21 @@ fun launchOnIO(block: suspend () -> Unit): Job {
  * @return Job that can be used to wait for completion with .join()
  */
 fun launchOnDefault(block: suspend () -> Unit): kotlinx.coroutines.Job {
-    return OneSignalDispatchers.launchOnDefault(block)
+    return if (ThreadingMode.useBackgroundThreading) {
+        OneSignalDispatchers.launchOnDefault {
+            try {
+                block()
+            } catch (e: Exception) {
+                Logging.error("Exception in launchOnDefault", e)
+            }
+        }
+    } else {
+        GlobalScope.launch(Dispatchers.Default) {
+            try {
+                block()
+            } catch (e: Exception) {
+                Logging.error("Exception in launchOnDefault", e)
+            }
+        }
+    }
 }

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/common/threading/ThreadingMode.kt

@@ -0,0 +1,25 @@
+package com.onesignal.common.threading
+
+import com.onesignal.debug.internal.logging.Logging
+
+/**
+ * Global threading mode switch that can be refreshed from remote config.
+ */
+internal object ThreadingMode {
+    @Volatile
+    var useBackgroundThreading: Boolean = false
+
+    fun updateUseBackgroundThreading(
+        enabled: Boolean,
+        source: String,
+    ) {
+        val previous = useBackgroundThreading
+        useBackgroundThreading = enabled
+
+        if (previous != enabled) {
+            Logging.info("OneSignal: ThreadingMode changed to useBackgroundThreading=$enabled (source=$source)")
+        } else {
+            Logging.debug("OneSignal: ThreadingMode unchanged (useBackgroundThreading=$enabled, source=$source)")
+        }
+    }
+}

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/CoreModule.kt

@@ -16,6 +16,8 @@ import com.onesignal.core.internal.device.IDeviceService
 import com.onesignal.core.internal.device.IInstallIdService
 import com.onesignal.core.internal.device.impl.DeviceService
 import com.onesignal.core.internal.device.impl.InstallIdService
+import com.onesignal.core.internal.features.FeatureManager
+import com.onesignal.core.internal.features.IFeatureManager
 import com.onesignal.core.internal.http.IHttpClient
 import com.onesignal.core.internal.http.impl.HttpClient
 import com.onesignal.core.internal.http.impl.HttpConnectionFactory
@@ -57,6 +59,7 @@ internal class CoreModule : IModule {
 
         // Params (Config)
         builder.register<ConfigModelStore>().provides<ConfigModelStore>()
+        builder.register<FeatureManager>().provides<IFeatureManager>()
         builder.register<ParamsBackendService>().provides<IParamsBackendService>()
         builder.register<ConfigModelStoreListener>().provides<IStartableService>()
 

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/backend/IParamsBackendService.kt

@@ -35,6 +35,7 @@ internal class ParamsObject(
     var locationShared: Boolean? = null,
     var requiresUserPrivacyConsent: Boolean? = null,
     var opRepoExecutionInterval: Long? = null,
+    val features: List<String> = emptyList(),
     var influenceParams: InfluenceParamsObject,
     var fcmParams: FCMParamsObject,
     val remoteLoggingParams: RemoteLoggingParamsObject,

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/backend/impl/ParamsBackendService.kt

@@ -68,6 +68,19 @@ internal class ParamsBackendService(
                 )
         }
 
+        val features =
+            responseJson.optJSONArray("features")
+                ?.let { featuresJson ->
+                    buildList {
+                        for (i in 0 until featuresJson.length()) {
+                            val featureName = featuresJson.optString(i, "")
+                            if (featureName.isNotBlank()) {
+                                add(featureName)
+                            }
+                        }
+                    }
+                } ?: emptyList()
+
         return ParamsObject(
             googleProjectNumber = responseJson.safeString("android_sender_id"),
             enterprise = responseJson.safeBool("enterp"),
@@ -84,6 +97,7 @@ internal class ParamsBackendService(
             requiresUserPrivacyConsent = responseJson.safeBool("requires_user_privacy_consent"),
             // TODO: New
             opRepoExecutionInterval = responseJson.safeLong("oprepo_execution_interval"),
+            features = features,
             influenceParams = influenceParams ?: InfluenceParamsObject(),
             fcmParams = fcmParams ?: FCMParamsObject(),
             remoteLoggingParams = remoteLoggingParams ?: RemoteLoggingParamsObject(),

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/config/ConfigModel.kt

@@ -290,6 +290,16 @@ class ConfigModel : Model() {
             setBooleanProperty(::clearGroupOnSummaryClick.name, value)
         }
 
+    /**
+     * Remote feature switches controlled by backend.
+     * Presence of a feature name indicates enabled.
+     */
+    var features: List<String>
+        get() = getListProperty(::features.name) { emptyList() }
+        set(value) {
+            setListProperty(::features.name, value)
+        }
+
     /**
      * The outcomes parameters
      */
@@ -329,6 +339,24 @@ class ConfigModel : Model() {
 
         return null
     }
+
+    override fun createListForProperty(
+        property: String,
+        jsonArray: JSONArray,
+    ): List<*>? {
+        if (property == ::features.name) {
+            return buildList {
+                for (i in 0 until jsonArray.length()) {
+                    val featureName = jsonArray.optString(i, "")
+                    if (featureName.isNotBlank()) {
+                        add(featureName)
+                    }
+                }
+            }
+        }
+
+        return null
+    }
 }
 
 /**

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/config/impl/ConfigModelStoreListener.kt

@@ -95,6 +95,7 @@ internal class ConfigModelStoreListener(
                     params.locationShared?.let { config.locationShared = it }
                     params.requiresUserPrivacyConsent?.let { config.consentRequired = it }
                     params.opRepoExecutionInterval?.let { config.opRepoExecutionInterval = it }
+                    config.features = params.features
                     params.influenceParams.notificationLimit?.let { config.influenceParams.notificationLimit = it }
                     params.influenceParams.indirectNotificationAttributionWindow?.let { config.influenceParams.indirectNotificationAttributionWindow = it }
                     params.influenceParams.iamLimit?.let { config.influenceParams.iamLimit = it }

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/features/FeatureFlag.kt

@@ -0,0 +1,27 @@
+package com.onesignal.core.internal.features
+
+/**
+ * Controls when remote config changes for a feature are applied.
+ */
+internal enum class FeatureActivationMode {
+    /**
+     * Apply config changes immediately during the current app run.
+     */
+    IMMEDIATE,
+
+    /**
+     * Latch value at startup; apply remote changes on next app run.
+     */
+    APP_STARTUP,
+}
+
+/**
+ * Backend-driven feature switches used by the SDK.
+ */
+internal enum class FeatureFlag(
+    val key: String,
+    val activationMode: FeatureActivationMode,
+) {
+    // Threading mode is selected once per app startup to avoid mixed-mode behavior mid-session.
+    BACKGROUND_THREADING("BACKGROUND_THREADING", FeatureActivationMode.APP_STARTUP),
+}