docs: dedicated executor

Author: Krzysztof Borowy

docs/advanced/DedicatedExecutor.md

@@ -0,0 +1,22 @@
+# Dedicated Thread Executor
+
+Android only feature.
+Would be mostly used in brownfield apps and [in edge cases with some android devices.](https://github.com/react-native-community/async-storage/issues/159)
+
+## Motivation
+
+Dedicated thread pool executor makes `AsyncStorage` use separate thread pool for its tasks execution.
+
+Use this feature if `THREAD_POOL_EXECUTOR` from `AsyncTasks`:
+
+- Is used in your app, so that background tasks are queued most of the time
+- Acts weird on your device (for example, waits for some time before execution)
+
+## How to use
+
+Add a `AsyncStorage_dedicatedExecutor` property to your `android/gradle.properties`:
+
+```
+AsyncStorage_dedicatedExecutor=true
+```
+

example/android/gradle.properties

@@ -19,3 +19,6 @@
 
 # This is an example of how you can change default DB size (6MB) to 10MB
 # AsyncStorage_db_size_in_MB=10
+
+# Enable dedicated thread pool executor
+AsyncStorage_dedicatedExecutor=true