PHP内核中重要的两个全局变量

在阅读PHP源码的时候，会遇到很多诸如：CG（），EG（）这样的宏，如果不了解这些宏的意义，会给理解源码造成很大困难。Zend引擎中有两个重要的全局变量结构体，就是Zend引擎关闭之前都会存在的变量：typedef struct _zend_compiler_globals zend_compiler_globals;
typedef struct _zend_executor_globals zend_executor_globals;/* Compiler */
#ifdef ZTS
# define CG（v） TSRMG（compiler_globals_id, zend_compiler_globals *, v）
int zendparse（void *compiler_globals）;
#else
# define CG（v）（compiler_globals.v）
extern ZEND_API struct _zend_compiler_globals compiler_globals;
int zendparse（void）;
#endif
/* Executor */
#ifdef ZTS
# define EG（v） TSRMG（executor_globals_id, zend_executor_globals *, v）
#else
# define EG（v）（executor_globals.v）
extern ZEND_API zend_executor_globals executor_globals;
#endifCG 的含义就是 compiler_globals ，Zend编译器相关的全局变量； EG 的含义就是 executor_globals，Zend执行器相关的全局变量；这两个结构都包含了很多元素，对理解PHP内核有很重要的意义：struct _zend_compiler_globals {
zend_stack bp_stack;
zend_stack switch_cond_stack;
zend_stack foreach_copy_stack;
zend_stack object_stack;
zend_stack declare_stack; zend_class_entry *active_class_entry; /* variables for list（） compilation */
zend_llist list_llist;
zend_llist dimension_llist;
zend_stack list_stack; zend_stack function_call_stack; char *compiled_filename; int zend_lineno;
int comment_start_line;
char *heredoc;
int heredoc_len; zend_op_array *active_op_array; HashTable *function_table; /* function symbol table */
HashTable *class_table; /* class table */ HashTable filenames_table; HashTable *auto_globals; zend_bool in_compilation;
zend_bool short_tags;
zend_bool asp_tags;
zend_bool allow_call_time_pass_reference; zend_declarables declarables; /* For extensions support */
zend_bool extended_info; /* generate extension information for debugger/profiler */
zend_bool handle_op_arrays; /* run op_arrays through op_array handlers */ zend_bool unclean_shutdown; zend_bool ini_parser_unbuffered_errors; zend_llist open_files; long catch_begin; struct _zend_ini_parser_param *ini_parser_param; int interactive; zend_uint start_lineno;
zend_bool increment_lineno; znode implementing_class; zend_uint access_type; char *doc_comment;
zend_uint doc_comment_len;#ifdef ZEND_MULTIBYTE
zend_encoding **script_encoding_list;
int script_encoding_list_size;
zend_bool detect_unicode; zend_encoding *internal_encoding; /* multibyte utility functions */
zend_encoding_detector encoding_detector;
zend_encoding_converter encoding_converter;
zend_encoding_oddlen encoding_oddlen;
#endif /* ZEND_MULTIBYTE */#ifdef ZTS
HashTable **static_members;
int last_static_member;
#endif
};
struct _zend_executor_globals {
zval **return_value_ptr_ptr; zval uninitialized_zval;
zval *uninitialized_zval_ptr; zval error_zval;
zval *error_zval_ptr; zend_function_state *function_state_ptr;
zend_ptr_stack arg_types_stack; /* symbol table cache */
HashTable *symtable_cache[SYMTABLE_CACHE_SIZE];
HashTable **symtable_cache_limit;
HashTable **symtable_cache_ptr; zend_op **opline_ptr; HashTable *active_symbol_table;
HashTable symbol_table; /* main symbol table */ HashTable included_files; /* files already included */ jmp_buf *bailout; int error_reporting;
int orig_error_reporting;
int exit_status; zend_op_array *active_op_array; HashTable *function_table; /* function symbol table */
HashTable *class_table; /* class table */
HashTable *zend_constants; /* constants table */ zend_class_entry *scope; zval *This; long precision; int ticks_count; zend_bool in_execution;
HashTable *in_autoload;
zend_function *autoload_func;
zend_bool full_tables_cleanup;
zend_bool ze1_compatibility_mode; /* for extended information support */
zend_bool no_extensions;#ifdef ZEND_WIN32
zend_bool timed_out;
#endif HashTable regular_list;
HashTable persistent_list; zend_ptr_stack argument_stack; int user_error_handler_error_reporting;
zval *user_error_handler;
zval *user_exception_handler;
zend_stack user_error_handlers_error_reporting;
zend_ptr_stack user_error_handlers;
zend_ptr_stack user_exception_handlers; /* timeout support */
int timeout_seconds; int lambda_count; HashTable *ini_directives;
HashTable *modified_ini_directives; zend_objects_store objects_store;
zval *exception;
zend_op *opline_before_exception; struct _zend_execute_data *current_execute_data; struct _zend_module_entry *current_module; zend_property_info std_property_info; zend_bool active; void *reserved[ZEND_MAX_RESERVED_RESOURCES];
};CentOS 6.3 安装LNMP （PHP 5.4,MyySQL5.6） http://www.linuxidc.com/Linux/2013-04/82069.htm在部署LNMP的时候遇到Nginx启动失败的2个问题 http://www.linuxidc.com/Linux/2013-03/81120.htmUbuntu安装Nginx php5-fpm MySQL（LNMP环境搭建） http://www.linuxidc.com/Linux/2012-10/72458.htm《细说PHP》高清扫描PDF+光盘源码+全套教学视频 http://www.linuxidc.com/Linux/2014-03/97536.htmPHP 的详细介绍：请点这里
PHP 的下载地址：请点这里本文永久更新链接地址：http://www.linuxidc.com/Linux/2014-11/109116.htm