Android™ How to Program, Second Edition

Concurrent Programming Uses

We’ll discuss many applications of concurrent programming. For example, when downloading a large file (e.g., an image, an audio clip or a video clip) over the Internet, the user may not want to wait until the entire clip downloads before starting the playback. To solve this problem, multiple threads can be used—one to download the clip, and another to play it. These activities proceed concurrently. To avoid choppy playback, the threads are synchronized (that is, their actions are coordinated) so that the player thread doesn’t begin until there’s a sufficient amount of the clip in memory to keep the player thread busy. The Java Virtual Machine (JVM) creates threads to run programs and threads to perform housekeeping ...