The document summarizes the PHP lifecycle when used with Apache. It describes the request process from the client request, Apache parsing the request and handling it, to PHP parsing, compiling and executing the script. It provides code examples from key points in the PHP parsing and execution process within the Zend engine. Sample requests are outlined from client to server processing and the PHP opcodes and execution.

1. The PHP Lifecycle
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Tel : 86111
Mail: laruence@yahoo.com.cn

2. Summary
• B/S(HTTP Request Cycle)
• Apache Life Cycle
• Apache Parse Request Cycle
• PHP Life Cycle
• Cooperating with Apache
• PHP Parse/Execute Process
• Now We Can…
Linux/Unix + Apache 1.3x + PHP 5.x

3. B/S
1. Client Request
2. Server Parse Requst and Send Response
3. Client interpret Responded Text/HTML/Json etc…

4. Apache Life Cycle

5. Apache Parse Request Cycle

6. PHP Life Cycle
• In command line mode(CLI)

7. PHP Life Cycle con’t
• PHP_MODULE_ENTRY(php_mysql.c 215 行 )

8. PHP Life Cycle con’t
• PHP_MINIT_FUNCTION(php_mysql.c 378 行 )

9. PHP Life Cycle con’t
• PHP_RINIT_FUNCTION(php_mysql.c 473 行 )

10. PHP Life Cycle con’t
• PHP_SHUTDOWNS(php_mysql.c 403 行 )

11. PHP Life Cycle con’t
• In DSO mode
– Single process

12. PHP Life Cycle con’t
• In DSO mode
– Multiprocess

13. PHP Life Cycle con’t
• In CGI mode
– Multithreaded

14. Cooperation
• Apache 1.3x + PHP 5.x in DSO mode
• Dynamic Shared Objects (DSO)
– mod_dso
• src/modules/standard/mod_so.c 347 行

15. Cooperation con’t
• Php Module 注册 Handler
– mod_php5.c 963 行

16. Cooperation con’t
• Php Module 注册 Handler
– mod_php5.c 987 行

17. Cooperation con’t
• http.conf

18. PHP Parse/Execute Process

19. PHP Parse/Execute Process con’t
• Scan(lex)
– Zend/zend_language_scanner.c 3047 行
ZEND_API zend_op_array *compile_file(zend_file_handle *file_handle, int type TSRMLS_DC){
retval = op_array;
….
return retval;}
– Zend/zend_language_scanner.l
T_OPEN_TAG: '<?php '
=
<?php T_LNUMBER: '1'
$sum = 1 + 2; +
echo “1+2=“.$sum; T_LNUMBER: '2'
?> T_ECHO: 'echo''
T_CONSTANT_ENCAPSED_STRI
NG: ''1+2=''.
T_CLOSE_TAG: '?>'

20. PHP Parse/Execute Process con’t
• Parse/Complie(yacc)
– zend_language_parser.y
T_OPEN_TAG: '<?php '
= Opcode Op1 Op2 Result
T_LNUMBER: '1' ADD 1 2 $tmp0
+ ASSIGN $cv0(sum) $tmp0 $var1
T_LNUMBER: '2' CONCAT '1+2=' $cv0(sum) $tmp2
T_ECHO: 'echo'' ECHO $tmp2
T_CONSTANT_ENCAPSED_STRI RETURN 1
NG: ''1+2=''.
T_CLOSE_TAG: '?>'

21. PHP Parse/Execute Process con’t
• Execute
– Zend/zend_execute.c
void (*zend_execute) (zend_op_array *op_array TSRMLS_DC);
• Zend_op_array
– Zend/zend_compile.h
struct zend_op{
opcode_handler_t handler;
znoderesult;
znodeop1;
znodeop2;
ulongextended_value;
uintlineno;
zend_ucharopcode;
};

22. PHP Parse/Execute Process con’t
• Execute
– Zend/zend_opcode.c 428 行

23. A sample
• Clien Request

24. A sample
• http_main.c 8053
– main() call ap_main
• ap_main => REALMAIN
– REALMAIN(argc, argv)
– http_main.c
• child_main
– Call child_sub_main 6134
• chile_sub_main
– loop worker
– call ap_process_request(r) on request
• http_reqeust.c 1308
• ap_process_request
– call process_request_internal
• process_request_internal
– call ap_invoke_handler
Application/x-httpd-php -> send_parsed_php

25. A sample
• Server Pares
– URI
• Filename -> /test/index.php
– User Auth
– …
– MIME type Check
• application/x-httpd-http
– Call handler
• send_parsed_php(request_rec *)
• Zend_execute_script(…..request_rec->filename);

26. A sample
• Zend/zend.c 1073 行

27. A sample
• Index.php
<?php
echo 2+3;
?>

28. A sample
• Zend_language_scanner.l 362 行
• Zend_language_parse.c 62 行

29. A sample
• Parser
– Zend_language_parse.y
– Zend_compile.c 258 行

30. A sample
• Opcodes

31. A sample
• Zend_execute zend.c 594 行
– Zend_execute => execute
• execute zend_vm_execute.h 34 行
ZEND_API void execute(zend_op_array *op_array TSRMLS_DC)
• Generate Output
• Return to Apache Server process
• Server send Responds Text to Client.

32. Now We Can….
• 1, 服务器的 Access log 没有任何输出
• 2, 隐藏 PHP 文件类型
• 3, PHP 出错的阶段
• 4, 编写 PHP 扩展
• 5, …

33. Documents
• 《 Apache Server 源代码分析》
• 《 Writing Apache Modules with Perl and C 》
• 《 Extending and Embedding PHP 》
• 《 PHP 手册》：“ Zend API ：深入 PHP 内核”
• http://blog.csdn.net/laruence

34. 谢谢大家！