php内核分析（三）－全局变量

最新推荐文章于 2021-05-03 16:59:43 发布

ding_zhi_jie

最新推荐文章于 2021-05-03 16:59:43 发布

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本文详细介绍了PHP-7.1.0RC3版本中编译器全局变量CG的具体结构与内容，包括循环变量堆栈、活动类入口、编译文件名等，并概述了全局变量SG与EG的作用及部分字段。

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这里阅读的php版本为PHP-7.1.0 RC3，阅读代码的平台为linux

CG

CG是从全局的compiler_global中获取属性值，里面存储的就是编译过程使用到的全局变量。

 
struct _zend_compiler_globals {
 
    zend_stack loop_var_stack;
 
 
 
    zend_class_entry *active_class_entry;
 
 
 
    zend_string *compiled_filename;
 
 
 
    int zend_lineno;
 
 
 
    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 parse_error;
 
    zend_bool in_compilation;
 
    zend_bool short_tags;
 
 
 
    zend_bool unclean_shutdown;
 
 
 
    zend_bool ini_parser_unbuffered_errors;
 
 
 
    zend_llist open_files;
 
 
 
    struct _zend_ini_parser_param *ini_parser_param;
 
 
 
    uint32_t start_lineno; // 执行文件开始执行的行号
 
    zend_bool increment_lineno;
 
 
 
    zend_string *doc_comment;
 
    uint32_t extra_fn_flags;
 
 
 
    uint32_t compiler_options; /* set of ZEND_COMPILE_* constants */
 
 
 
    HashTable const_filenames;
 
 
 
    zend_oparray_context context;
 
    zend_file_context file_context;
 
 
 
    zend_arena *arena;
 
 
 
    zend_string *empty_string;
 
    zend_string *one_char_string[256];
 
    zend_string **known_strings;
 
    uint32_t    known_strings_count;
 
 
 
    HashTable interned_strings;
 
 
 
    const zend_encoding **script_encoding_list;
 
    size_t script_encoding_list_size;
 
    zend_bool multibyte;
 
    zend_bool detect_unicode;
 
    zend_bool encoding_declared;
 
 
 
    zend_ast *ast;
 
    zend_arena *ast_arena;
 
 
 
    zend_stack delayed_oplines_stack;
 
 
 
#ifdef ZTS
 
    zval **static_members_table;
 
    int last_static_member;
 
#endif
 
};

SG

 
SG是从全局的sapi_global中获取属性值
 
 
 
// TODO：更新
 
typedef struct _sapi_globals_struct {
 
    void *server_context;
 
    sapi_request_info request_info; // 请求信息
 
    sapi_headers_struct sapi_headers;
 
    int64_t read_post_bytes;
 
    unsigned char post_read;
 
    unsigned char headers_sent;
 
    zend_stat_t global_stat;
 
    char *default_mimetype;
 
    char *default_charset;
 
    HashTable *rfc1867_uploaded_files;
 
    zend_long post_max_size;
 
    int options;
 
    zend_bool sapi_started;
 
    double global_request_time;
 
    HashTable known_post_content_types;
 
    zval callback_func;
 
    zend_fcall_info_cache fci_cache;
 
} sapi_globals_struct;

EG

EG是从executor_globals中获取变量

 
// TODO: 更新
 
struct _zend_executor_globals {
 
    zval uninitialized_zval;
 
    zval error_zval;
 
 
 
    /* symbol table cache */
 
    zend_array *symtable_cache[SYMTABLE_CACHE_SIZE];
 
    zend_array **symtable_cache_limit;
 
    zend_array **symtable_cache_ptr;
 
 
 
    zend_array symbol_table;        /* main symbol table */
 
 
 
    HashTable included_files;    /* files already included */
 
 
 
    JMP_BUF *bailout;
 
 
 
    int error_reporting;
 
    int exit_status;
 
 
 
    HashTable *function_table;    /* function symbol table */
 
    HashTable *class_table;        /* class table */
 
    HashTable *zend_constants;    /* constants table */
 
 
 
    zval          *vm_stack_top;
 
    zval          *vm_stack_end;
 
    zend_vm_stack  vm_stack;
 
 
 
    struct _zend_execute_data *current_execute_data;
 
    zend_class_entry *fake_scope; /* used to avoid checks accessing properties */
 
 
 
    zend_long precision;
 
 
 
    int ticks_count;
 
 
 
    HashTable *in_autoload;
 
    zend_function *autoload_func;
 
    zend_bool full_tables_cleanup;
 
 
 
    /* for extended information support */
 
    zend_bool no_extensions;
 
 
 
    zend_bool vm_interrupt;
 
    zend_bool timed_out;
 
    zend_long hard_timeout;
 
 
 
#ifdef ZEND_WIN32
 
    OSVERSIONINFOEX windows_version_info;
 
#endif
 
 
 
    HashTable regular_list;
 
    HashTable persistent_list;
 
 
 
    int user_error_handler_error_reporting;
 
    zval user_error_handler;
 
    zval user_exception_handler;
 
    zend_stack user_error_handlers_error_reporting;
 
    zend_stack user_error_handlers;
 
    zend_stack user_exception_handlers;
 
 
 
    zend_error_handling_t  error_handling;
 
    zend_class_entry      *exception_class;
 
 
 
    /* timeout support */
 
    zend_long timeout_seconds;
 
 
 
    int lambda_count;
 
 
 
    HashTable *ini_directives;
 
    HashTable *modified_ini_directives;
 
    zend_ini_entry *error_reporting_ini_entry;
 
 
 
    zend_objects_store objects_store;
 
    zend_object *exception, *prev_exception;
 
    const zend_op *opline_before_exception;
 
    zend_op exception_op[3];
 
 
 
    struct _zend_module_entry *current_module;
 
 
 
    zend_bool active;
 
    zend_bool valid_symbol_table;
 
 
 
    zend_long assertions;
 
 
 
    uint32_t           ht_iterators_count;     /* number of allocatd slots */
 
    uint32_t           ht_iterators_used;      /* number of used slots */
 
    HashTableIterator *ht_iterators;
 
    HashTableIterator  ht_iterators_slots[16];
 
 
 
    void *saved_fpu_cw_ptr;
 
#if XPFPA_HAVE_CW
 
    XPFPA_CW_DATATYPE saved_fpu_cw;
 
#endif
 
 
 
    zend_function trampoline;
 
    zend_op       call_trampoline_op;
 
 
 
    void *reserved[ZEND_MAX_RESERVED_RESOURCES];
 
};