PHP内核两大流程之请求处理_PHP教程
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2024-02-10 10:25:52
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PHP内核两大流程之请求处理
static int php_handler(request_rec *r)
{
/* Initiliaze the context */
php_struct * volatile ctx;
void *conf;
apr_bucket_brigade * volatile brigade;
apr_bucket *bucket;
apr_status_t rv;
request_rec * volatile parent_req = NULL;
TSRMLS_FETCH();
......
zend_file_handle zfd;
zfd.type = ZEND_HANDLE_FILENAME;
zfd.filename = (char *) r->filename;
zfd.free_filename = 0;
zfd.opened_path = NULL;
zend_execute_scripts(ZEND_INCLUDE TSRMLS_CC, NULL, 1, &zfd);
......
}
ZEND_API int zend_execute_scripts(int type TSRMLS_DC, zval **retval, int file_count, ...) /* {{{ */
{
......
EG(active_op_array) = \
zend_compile_file(file_handle, type TSRMLS_CC);
......
zend_execute(EG(active_op_array) TSRMLS_CC);
......
}
ZEND_API void execute(zend_op_array *op_array TSRMLS_DC)
{
// 初始化执行上下文
zend_execute_data execute_data;
// 如果有异常就退出执行
if (EG(exception)) {
return;
}
/* Initialize execute_data */
EX(fbc) = NULL; // 初始化正在调用的函数
EX(object) = NULL; // 初始化正在调用的对象
EX(old_error_reporting) = NULL; // 初始化错误报告变量
// 为执行栈分配空间
if (op_array->T T);
} else {
EX(Ts) = (temp_variable *) safe_emalloc(sizeof(temp_variable), op_array->T, 0);
}
// 为临时变量分配空间并初始化这些空间
EX(CVs) = (zval***)do_alloca(sizeof(zval**) * op_array->last_var);
memset(EX(CVs), 0, sizeof(zval**) * op_array->last_var);
EX(op_array) = op_array;
// 切换执行上下文
EX(original_in_execution) = EG(in_execution);
EX(symbol_table) = EG(active_symbol_table);
EX(prev_execute_data) = EG(current_execute_data); // 将当前全局变量中的执行数据压栈
EG(current_execute_data) = &execute_data; // 将当前执行上下文压栈
EG(in_execution) = 1;
// 初始化第一个指令(opcode)
/*
#define ZEND_VM_SET_OPCODE(new_op) \
CHECK_SYMBOL_TABLES() \
EX(opline) = new_op
execute_data.opline 为当前执行的 opcode
*/
if (op_array->start_op) {
ZEND_VM_SET_OPCODE(op_array->start_op);
} else {
ZEND_VM_SET_OPCODE(op_array->opcodes);
}
if (op_array->uses_this && EG(This)) {
EG(This)->refcount++; /* For $this pointer */
if (zend_hash_add(EG(active_symbol_table), "this", sizeof("this"), &EG(This), sizeof(zval *), NULL)==FAILURE) {
EG(This)->refcount--;
}
}
// 将存储opline的内存地址赋给 executor_globals.online_ptr ，可以实时跟踪opcode的执行
EG(opline_ptr) = &EX(opline);
EX(function_state).function = (zend_function *) op_array;
EG(function_state_ptr) = &EX(function_state);
#if ZEND_DEBUG
/* function_state.function_symbol_table is saved as-is to a stack,
* which is an intentional UMR. Shut it up if we're in DEBUG.
*/
EX(function_state).function_symbol_table = NULL;
#endif
while (1) {
#ifdef ZEND_WIN32
if (EG(timed_out)) {
zend_timeout(0);
}
#endif
// 循环调用每个opline的 handler 函数，如果是推出函数的话，返回值大于0，就退出
if (EX(opline)->handler(&execute_data TSRMLS_CC) > 0) {
return;
}
}
zend_error_noreturn(E_ERROR, "Arrived at end of main loop which shouldn't happen");
}