Android Asynchronous Messaging Architecture : Android Looper Analysis.
Introduction to concurrency. The Java programming language and the Java virtual machine (JVM) have been designed to support concurrent programming, and all execution takes place in the context of threads. Objects and resources can be accessed by many separate threads; each thread has its own path of execution but can potentially access any object in the program. The programmer must ensure read and write access to objects is properly coordinated (or "synchronized") between threads. Thread synchronization ensures that objects are modified by only one thread at a time and that threads are prevented from accessing partially updated objects during modification by another thread. The Java language has built-in constructs to support this coordination. More details on concurrency in Java [Remember Android apps are written primarily in java programming language] can be obtained from. https://en.wikipedia.org/wiki/Java_concurrency https://www.tutorialspoint.com/java/ja