了解Php内核

了解PHP内核
12年10月29日星期⼀一

我是……
Er、T0ny
中心的学生
写PHP的程序员
喜欢各种折腾


PHP代码是如何被执行的？


C代码 PHP代码

gcc -o xxx ???

$> xxx


PHP的生命周期


mod_php cli cgi/fastcgi ...

SAPI

PHP API
streams, output, etc.

PHP (core)
Extensions
mysql , standard library, etc

Zend API Zend Extension API

Zend Engine

$ php test.php

Call Each extension’s MINIT

Request test.php

Call Each extension’s RINIT

Execute test.php

Call Each extension’s RSHUTDOWN

Finish cleaning up after test.php

Call Each extension’s MSHUTDOWN

Terminate php


PHP脚本的执行


PHP内核
<?php
echo “hi”; 词法分析
?>
语法分析

Zend Engine
(执行 opCodes)
hi


词法分析
Lex/Flex/re2c


array (
array (
<?php 0 => 368, // #define T_OPEN_TAG 368
1 => '<?php',
echo $hi; 2 => 1, // LINE NO
?> ),
array (
0 => 316, // #define T_ECHO 316
1 => 'echo',
2 => 2,
),
array (
0 => 371, // #define T_WHITESPACE 371
1 => ' ',
2 => 2,
token_get_all ),
array (
0 => 309, // #define T_VARIABLE 309
1 => '$haha',
2 => 2,
),
4 => ';',
)
@see Zend/zend_language_parser.c

<?php T_OPEN_TAG ?> T_CLOSE_TAG

$var T_VARIABLE if T_IF

function T_FUNCTION for T_FOR

echo T_ECHO exit T_EXIT

123 tokens php5.3


语法分析
Yacc/Bison


T_ECHO echo_expr_list ';'

echo_expr_list:
echo_expr_list ',' expr { ... }
| expr { ... }

{ ... }

zend_do_echo()

void zend_do_echo(const znode *arg TSRMLS_DC)
{
zend_op *opline = get_next_op(CG(active_op_array) TSRMLS_CC);

opline->opcode = ZEND_ECHO;
opline->op1 = *arg;
SET_UNUSED(opline->op2);
}

@see Zend/zend_compile.c

zend_op 出场！


struct _zend_op {
// 执行该opcode时调用的处理函数
opcode_handler_t handler;
znode result;
znode op1;
znode op2;
ulong extended_value;
uint lineno;
zend_uchar opcode; // opcode代码
};


opcodes的执行


switch call goto

switch (opcode){ switch (opcode){
case ZEND_ADD: case ZEND_ADD:
break; goto zend_add:
case ZEND_CALL: break;
break; ...
zend_add:

call ZEND_ADD_HANDLER()


opcode * 25
+ zend_vm_decode[op->op1.op_type] * 5
+ zend_vm_decode[op->op2.op_type];

static const opcode_handler_t labels[]

3851 indexs php5.3


zend_op

op_array zend_op

zend_op

...


symbol_talble

*active_op_array *active_symbol_talble

op_array1 op_array2 ...

execute_data execute_data ...


让我们再来⼀一次……


.php SAPI Compiler
• Firefox/Chrome • Apache/Nginx • 词法分析
• Console • CLI • 语法分析
• Embed

Executor OPCODES
Output • Main Script
Buffer • Switch/Call/Goto
• Function Table
•Console
• Class Table


Finally……


<?php
$a = 3;
$b = 5;

if($a = 5 || $b = 7) {
$a++;
$b++;
}

$a=? $b=?

<?php
$a = 3;
$b = 5;

if( $a = 5 || $b = 7
$a ) {
$a++;
$b++;
}

答案：
Zend/zend_language_parser.y

关于TIPI

www.php-internal.com


reeze er

pan


Q&A


谢谢

欢迎联系我：

QQ：487223*

email: er@zhangabc.com

gtalk: er@zhangabc.com

blog: www.zhangabc.com


了解Php内核

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