CS 240 Advanced Programming Concepts Class Intro Java

CS 240: Advanced Programming Concepts Class Intro Java Basics Android

Outline • Meta Data • Expectations • Introduction To Java • Fiddling With Android

Meta Data • • • Instructor: Dr. Frank Jones • • • 3372 TMCB 801 -422 -7656 frjones@cs. byu. edu Class Website: https: //students. cs. byu. edu/~cs 240 ta/fall 2016 Course Language: Java Course IDE: Android Studio • (https: //developer. android. com/studio/index. html) Officially Supported Device: Kindle Fire • (https: //www. amazon. com/dp/B 00 TSUGXKE/ref=fs_ods_fs_tab_fd) Recommended Emulator: AMIDu. OS • (http: //www. amiduos. com/#!)

Expectations • • • Respect • • Self – be on time, be prepared, raise your hand, speak politely, pay attention Others – be on time, be prepared, raise your hand, speak politely, pay attention Use of Electronic Devices • • • Appropriate Timely Revocable Effort • • • Significant: 3 “easy” projects; 2 “serious” projects Individual: You are on your own*; !!Programming Exam!! On Time • No “Time Stamp” Submissions *TAs and instructor are here to help

Expectations Cont. • Fun

Java: A VERY Brief Introduction

Why Java? • C++ • • Cross Platform: Write “once” compile many, run anywhere… • • Cross Platform: Write “once” compile “once”, run anywhere… Supports Object Oriented Programing: Supports classes etc. Familiar Syntax: Based upon C Fast (very) • Java Truly Object Oriented Language: Everything is a class Familiar Syntax: Closely resembles C++ Fast (enough very)

C++ (Compiled Language) Model

Interpreted Language Model What does this mean for performance? . .

Example: C++ vs Interpreted Java • Demo (with –Xint flag) Note: Credit is given to the blog “beyondjava. net” which provided the example java source code this demo has been derived from… http: //www. beyondjava. net/blog/a-close-look-at-javas-jit-dont-waste-your-time-on-local-optimizations/ … and to “About. com” which made available the high resolution timer class utilized in the c++ implementation. http: //cplus. about. com/od/howtodothingsi 2/a/timing. htm

Bring on the JIT (Just In Time) Compiler (Note: This example is based on Oracle’s Jrockit JVM) http: //docs. oracle. com/cd/E 13150_01/jrockit_jvm/jrockit/geninfo/diagnos/underst_jit. html

But Wait, There’s More… • Runtime Optimization • • Function Inlining Selective Compilation Data Optimizations Etc… http: //docs. oracle. com/cd/E 13150_01/jrockit_jvm/jrockit/geninfo/diagnos/underst_jit. html

Back to Performance Demo… This time we enable the JIT and optimizations… (i. e. no –Xint flag)

Results… Mean Duration of Iterations in µSeconds Java C++ Optimized 300 250 µSeconds 200 150 100 50 0 1 3 5 7 9 11 13 15 17 19212325 272931 33 35 37 39414345 474951 5355 5759616365676971 73 75 77 79818385 87899193959799 Sequential Iteration Count

Result 2 (a bit easier)… Mean Duration of Iterations in µSeconds 300 250 µSeconds 200 150 100 50 0 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73 75 77 79 81 83 85 87 8991 93 95 97 99 Sequential Iteration Count

Yet Another Java Resource… • http: //docs. oracle. com/javase/tutorial/java/TOC. html

Working With a Physical Device • https: //developer. android. com/studio/run/device. html