# Coroutine::getContext [TOC] > v4.3.0后可用 獲取當前協程的上下文對象 ~~~ function Coroutine::getContext() : Coroutine\Context ~~~ 接受一個可選參數cid, 默認返回當前協程的上下文對象 ## 代碼 ~~~ function func(callable $fn, ...$args) { go(function () use ($fn, $args) { $fn(...$args); echo 'Coroutine#' . Co::getCid() . ' exit' . PHP_EOL; }); } /** * Compatibility for lower version * @param object|Resource $object * @return int */ function php_object_id($object) { static $id = 0; static $map = []; $hash = spl_object_hash($object); return $map[$hash] ?? ($map[$hash] = ++$id); } class Resource { public function __construct() { echo __CLASS__ . '#' . php_object_id((object)$this) . ' constructed' . PHP_EOL; } public function __destruct() { echo __CLASS__ . '#' . php_object_id((object)$this) . ' destructed' . PHP_EOL; } } $context = new Co\Context(); assert($context instanceof ArrayObject); assert(Co::getContext() === null); func(function () { $context = Co::getContext(); assert($context instanceof Co\Context); $context['resource1'] = new Resource; $context->resource2 = new Resource; func(function () { Co::getContext()['resource3'] = new Resource; Co::yield(); Co::getContext()['resource3']->resource4 = new Resource; Co::getContext()->resource5 = new Resource; }); }); Co::resume(2); ~~~ ## 輸出 ~~~ Resource#1 constructed Resource#2 constructed Resource#3 constructed Coroutine#1 exit Resource#2 destructed Resource#1 destructed Resource#4 constructed Resource#5 constructed Coroutine#2 exit Resource#5 destructed Resource#3 destructed Resource#4 destructed ~~~ ## 作用 * 協程退出后上下文自動清理 (如無其它協程或全局變量引用) * 無defer注冊和調用的開銷 (無需注冊清理方法, 無需調用函數清理) * 無PHP數組實現的上下文的哈希計算開銷 (在協程數量巨大時有一定好處) * `Co\Context`使用ArrayObject, 滿足各種存儲需求 (既是對象, 也可以以數組方式操作) ## 實現 https://github.com/swoole/swoole-src/pull/2399