Coroutine Based Concurrency with PHP and Swoole

PHP Swoole has gained traction during the past several years. More and more people are interested with started to try PHP Swoole and use coroutine in PHP to build high performance, large scale web services, online game, micro-services.

Transcript

1. Coroutine Based Concurrency with PHP and Swoole Bruce Dou | @doubaokun bruce@transfon.com 20th Feb 2020 PHPUK2020
2. About me • Founder at Transfon • Twitter: @doubaokun • Email: bruce@transfon.com • Linkedin: linkedin.com/in/brucedou • Github: github.com/doubaokun Twitter: @doubaokun
3. Agenda • Rethinking about software development • Concurrency, I/O, Scheduling and OS • Coroutine: Cooperative multi-tasking • Swoole Coroutine Internal • Swoole • Coroutine and Swoole code samples • Demo Twitter: @doubaokun
4. Rethinking about software development Twitter: @doubaokun
5. Twitter: @doubaokun Mapping real world problems onto machine
6. Execution Unit Twitter: @doubaokun
7. I/O and Task Processing Twitter: @doubaokun
8. Twitter: @doubaokun
9. Twitter: @doubaokun Mapping real world problems onto machine with several levels abstraction
10. Twitter: @doubaokun
11. Twitter: @doubaokun Mapping real world problems onto machine with several levels abstraction with real world limitations in mind
12. Twitter: @doubaokun 1. 1 CPU cycle 0.3 ns 2. Main memory access 120 ns 3. Goroutine 170 ns 4. Swoole Coroutine 190 ns 5. Linux OS context switch 1,000 ns 6. Linux thread launch 5,000 ns 7. Linux process launch 20,000 ns 8. Per-thread stack is 8MB (ulimit -s)
13. • Unpredictable external performance • Client side I/O • Server side I/O • Queue theory Twitter: @doubaokun
14. Twitter: @doubaokun wait time utilization
15. Twitter: @doubaokun Mapping real world problems onto machine with several levels abstraction with real world limitations in mind about management and structure
16. Scaling up the power Twitter: @doubaokun
17. Scaling up the power Twitter: @doubaokun
18. = Scaling the concurrency Twitter: @doubaokun
19. What is Concurrency? Twitter: @doubaokun
20. Concurrency is managing multi-tasking Twitter: @doubaokun
21. Concurrency is managing multi-tasking in both real world and machine world Twitter: @doubaokun
22. Twitter: @doubaokun
23. What is blocking Twitter: @doubaokun
24. Twitter: @doubaokun
25. Blocking is sequential Twitter: @doubaokun
26. Blocking and sequential are the nature of human mind and machine Twitter: @doubaokun
27. Blocking and sequential are the nature of a single Execution Unit Twitter: @doubaokun
28. What is blocking I/O Twitter: @doubaokun
29. Twitter: @doubaokun
30. Blocking I/O is the nature of machine Twitter: @doubaokun
31. What is async I/O Twitter: @doubaokun
32. Twitter: @doubaokun
33. The nature of real world I/O Twitter: @doubaokun
34. The nature of real world is better resources utilisation Twitter: @doubaokun
35. Mapping real world to machine Twitter: @doubaokun
36. Mapping real world to machines: Unlimited Execution Unit and I/O vs Limited resources and machines Twitter: @doubaokun
37. Concurrency is hard Twitter: @doubaokun
38. Concurrency models • Process • Process pool • Thread • Thread pool • Single thread async I/O • Light weight thread: Fiber / Coroutine / … Twitter: @doubaokun
39. Concurrency is hard • Inefficient scaling • Race condition Twitter: @doubaokun
40. https://unixism.net/2019/04/linux-applications-performance-introduction/ Twitter: @doubaokun Performance of Concurrent I/O models
41. Machine I/O Concurrency Twitter: @doubaokun
42. Decoupling I/O and CPU Twitter: @doubaokun
43. Async machine I/O Twitter: @doubaokun
44. Twitter: @doubaokun
45. Event based callbacks ? Twitter: @doubaokun
46. not the nature of human mind Twitter: @doubaokun
47. Async machine I/O should be abstracted Twitter: @doubaokun
48. Understand the machine better Twitter: @doubaokun
49. Concurrency and Operating System Twitter: @doubaokun
50. What is a function? Twitter: @doubaokun
51. a sequence of instructions that takes inputs and returns outputs Twitter: @doubaokun
52. function add($a, $b) { return $a + $b; } Twitter: @doubaokun
53. What is Context? Twitter: @doubaokun
54. Twitter: @doubaokun
55. Call Stack and Stack Frame Twitter: @doubaokun
56. function add($a, $b) { return $a + $b; } function plus5($c, 5) { return add($c, 5); } Twitter: @doubaokun
57. Twitter: @doubaokun
58. What is context switch? Twitter: @doubaokun
59. Twitter: @doubaokun
60. History of multi-tasking in OS Twitter: @doubaokun
61. 1. No scheduler Twitter: @doubaokun
62. 2. Cooperative Scheduler Non-preemptive Twitter: @doubaokun
63. 3. Preemptive timer interrupt scheduler Twitter: @doubaokun
64. Twitter: @doubaokun
65. Twitter: @doubaokun
66. Thread context switch can be expensive Twitter: @doubaokun
67. Not scalable Twitter: @doubaokun
68. Light weight thread Twitter: @doubaokun
69. Light weight Execution Unit Twitter: @doubaokun
70. Light weight Execution Unit provided by machine/library Twitter: @doubaokun
71. Light weight Execution Unit provided by machine to map real world problems Twitter: @doubaokun
72. Light weight Execution Unit provided by machine to map real world problems to execute real world tasks Twitter: @doubaokun
73. What is Coroutine? Twitter: @doubaokun
74. “Coroutines are computer components that generalise subroutines for non-preemptive multitasking, by allowing execution to be suspended and resumed.” - Wikipedia Twitter: @doubaokun
75. “a type of functions that enables concurrency via cooperative multitasking” Twitter: @doubaokun
76. Cooperative multi-tasking Twitter: @doubaokun
77. Multi-tasking management strategy Twitter: @doubaokun
78. On machine: User space yield and resume Twitter: @doubaokun
79. 1 3 start 2 4 Twitter: @doubaokun
80. Twitter: @doubaokun
81. Swoole Twitter: @doubaokun
82. https://www.swoole.co.uk/ https://github.com/swoole/swoole-src @php_swoole Coroutine-based concurrency library with PHP syntax Twitter: @doubaokun
83. Twitter: @doubaokun
84. Super fast Twitter: @doubaokun
85. Super fast https://tsh.io/blog/swoole-is-it-node-in-php-or-am-i-wrong/ Twitter: @doubaokun
86. Super fast Twitter: @doubaokun
87. Twitter: @doubaokun • Async I/O • Reuse states • Coroutine • Coroutine scheduler based on I/O
88. Twitter: @doubaokun
89. Swoole server Twitter: @doubaokun
90. HTTP server with PHP Swoole Twitter: @doubaokun
91. Server structure Twitter: @doubaokun
92. Server structure Twitter: @doubaokun
93. Swoole Coroutine Internal Twitter: @doubaokun
94. Twitter: @doubaokun
95. Use cases Twitter: @doubaokun
96. Twitter: @doubaokun
97. Common pitfalls Twitter: @doubaokun
98. Twitter: @doubaokun Common pitfalls • Looking to run it on M$ Windows • Trying to run it with PHP-FPM • Stateless mind • Variable scope: super global, global, static, local variables • Blocking within Coroutine context • Exception handling • Exit
99. Code samples Twitter: @doubaokun
100. Coroutine Twitter: @doubaokun
102. 1 3 start 2 4 Coroutine yield and resume
103. 2 1 3 2 Coroutine structure
104. Server Twitter: @doubaokun
105. Server response timeout
106. Timer Twitter: @doubaokun
107. Timer
108. Client Twitter: @doubaokun
109. HTTP Client
110. Channel Twitter: @doubaokun
112. Coroutine Pooling Twitter: @doubaokun
115. Linux process Twitter: @doubaokun
117. HashTable Twitter: @doubaokun
119. Task worker Twitter: @doubaokun
122. Coroutine Server Twitter: @doubaokun
123. Twitter: @doubaokun
124. Demo Twitter: @doubaokun
125. https://www.swoole.co.uk/ https://twitter.com/php_swoole https://github.com/swoole/swoole-src https://github.com/21days-dev/phpuk2020 Thank you