(phpconftw2012) PHP as a Middleware in Embedded Systems

It is used by sosorry at PHPConf Taiwan 2012. In this presentation, we will see that why we need a middleware in embedded systems, and how PHP can play this role. Besides, some tasks about architecture design, porting libraries, development & debug, and performance tunning would be included.

Transcript

1. PHP as a Middleware in Embedded Systems @phpconftw2012
2. Hi, I'm sosorry
3. 不可能的電視 系統廠工程師
4. 本次分享 僅代表個人意見 不代表公司立場
5. 故事開始
6. 2012 年 , 連網電視正夯
7. 老闆想在電視上新增一個網路 App
8. 該如何開始？
9. 先來測個 API 吧
10. • Request the developer account to 3rd party • Get the technical document • Build the test environment • Download sample code • Test all APIs with JAVA • … OK
11. 杯具發生了 ...
12. 板子上沒有 JVM
13. 歡迎來到嵌入式系統的世界
14. An embedded system is a computer system designed for specific control functions within a larger system, often with real-time computing constraints. Embedded System
15. • No APT, no YUM • Hardware limitation • ! Scale • Deploy/update not easy
16. Back to the basics
17. Q1: app 在嵌入式系統是如何顯示的？
18. Display System Framebuffer Hardware Application GUI-ToolKit
19. In Embedded System /dev/fb driver SoC
20. application 受限於 GUI-Toolkit
21. Q2: 是否可以讓 UI 只做 UI ？
22. Software Glue source: http://www.furniturefromturkey.com/
23. Middleware Turnkey/Driver Hardware Application
24. Middleware Turnkey/Driver Hardware Application
25. Middleware Turnkey/Driver Hardware Application interface interface
26. Middleware Turnkey/Driver Hardware Application Portable Layer interface interface
27. Q3: 要能實做 3rd Party App 的基本需求？
28. • RESTFul API • JSON/XML data format • Symmetric/asymmetric encryption • SSL communication • Data storage • Multi-byte encoding
29. PHP as Software Glue in Embedded Systems
30. Why PHP
31. • Tiny, low resource usage • Community contribution (PEAR/PECL) • 3rd party API (Youtube/Twitter/Facebook...) • Integration with lots of libraries
32. • RESTFul API /cURL • JSON/XML data format /LibeXpat, Libxml2 • Symmetric/asymmetric encryption /Libmcrypt • SSL communication /OpenSSL • Data storage /SQLite3 • Multi-byte encoding /Libiconv • Inter-Process Communication /Socket, SHM • Core /PHP-CLI
33. PHP as a Middleware Turnkey/Driver Hardware Application
34. • Architecture design • Porting libraries • Development & debug • Performance tunning Tasks
35. Architecture Design
36. Web Server + PHP ？
37. • Apache MPM prefork + mod_php • Nginx + FastCGI • Lighttpd + PHP-FPM • Boa + PHP-CGI
38. 杯具又發生了 ...
39. • 資源吃很兇 • 不容易移植 • 記憶體洩漏 • 常常連不上
40. 砍掉重練
41. PHP Inter-Process Communication
42. PHP Native Code data exchange invoke
43. • Shared library PHP Native Code data exchange invoke
44. • Shared library • Embedded build (--enable-embed) PHP Native Code data exchange invoke
45. • Shared library • Embedded build (--enable-embed) • Shell command PHP Native Code data exchange invoke
46. • Shared library • Embedded build (--enable-embed) • Shell command • Socket PHP Native Code data exchange invoke
47. Socket Server
48. • Concurrent server (No multi-thread in PHP) • IPC mechanism (broadcast/multicast/unicast) • Client/Server command protocol • No framework, all things handmade Design
49. PHP Work Flow
50. Turnkey/Driver Hardware
51. Turnkey/Driver Hardware application interface storage socket server
52. Turnkey/Driver Hardware application interface storage socket server
53. Turnkey/Driver Hardware application interface storage socket server
54. Turnkey/Driver Hardware application interface You Tube storage socket server
55. Turnkey/Driver Hardware application interface Pandora You Tube storage socket server
56. Turnkey/Driver Hardware application interface Pandora Twitter You Tube storage socket server
57. Turnkey/Driver Hardware application interface Pandora Twitter You Tube storage socket server
58. Turnkey/Driver Hardware application interface Pandora Twitter You Tube storage socket server
59. Porting Libraries
60. • Prepare toolchain • Configure with minimized features • Resolve dependency & version conflict • Resolve compilation error • Test all functions in the target machine • Reduce library size
61. Development & Debug
62. • Ubuntu /OS • Vim & plugin /editor • Shell script /automation tool • Meld /visual diff and merge tool • SVN /version control system • Jira /bug tracking system Development Environment
63. • print_r(), var_dump() • Xdebug & xdebug_debug_zval() • log_errors & error_log in php.ini • debugging level in config.ini Console Debug
64. • Set breakpoint • Step into/step over/step out • Watch variables • Display call stack IDE Debug
66. Performance Tunning
67. • Xdebug • Kcachegrind • VLD (Vulcan Logic Disassembler) Profiling
68. • Stack/function traces • Code coverage analysis • Time tracking • Memory usage Xdebug
70. • Aggregate information from xdebug • Sort by time/memory/calls tracefile-analyser
72. • Analyze xdebug profiling data • Call graph viewer(callers/callees) Kcachegrind
74. • An opcode dumper VLD
75. A simple comparison
76. array_push
77. array assignment
78. # of Opcodes = 16
79. # of Opcodes = 10
80. Tunning
81. Alternative PHP Cache (APC) source: http://www.slideshare.net/shire/php-tek-2008-apc-facebook
82. DB is always the bottleneck
83. • 買好一點的硬體 • 優化 SQL 語法 • 關掉同步 commit • 增加寫入 buffer 的大小 • 增加 wait write 的 delay time • … 等等 常見招數
84. • Configuration • SQLITE_MAX_LENGTH=2147483647 • SQLITE_MAX_SQL_LENGTH=1073741824 • lock/unlock • $handle->busyTimeout($time) • Single statement • Concat SQL string • Begin; SQL; Commit; SQLite3 Tunning
85. • --enable-debug --enable-maintainer-zts • ext_skel $ vi ext/$extname/config.m4 $ ./buildconf $ ./configure –[with|enable]-$extname $ make $ ./php -f ext/$extname/$extname.php $ vi ext/$extname/$extname.c $ make Write an Extension
86. • Change debugging level during runtime • Dump debug information to a specific usb drive • inotify + blkid Extension for Debugging
87. Integration
88. 這又是另外一個故事了
89. Thanks
90. • Jeffrey Chen • Simon Wang Special Thanks
91. Q & A