php的垃圾收集机制是怎样的?解决方案
php的垃圾收集机制是怎样的?
如题...
是网上搜得tencent笔试题...
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只知道session的垃圾收集机制
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不懂，帮顶,期待高手.
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其他的手册上说,主要是资源会产后垃圾问题,但PHP4后已有记数功能,哪果资源没有被占用,会自动释放
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在PHP中，没有任何变量指向这个对象时，这个对象就成为垃圾。PHP会将其在内存中销毁；这是PHP 的GC垃圾处理机制，防止内存溢出。
当一个 PHP线程结束时，当前占用的所有内存空间都会被销毁，当前程序中所有对象同时被销毁。GC进程一般都跟着每起一个SESSION而开始运行的.gc目的是为了在session文件过期以后自动销毁删除这些文件.
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执行这些函数也可以起到回收作用
__destruct /unset/mysql_close
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php的垃圾回收机制并不需要程序员考虑，
只要对不用的resource及时的关闭，对占用资源大的变量及时unset就可以了。
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php对session有明确的gc处理时间设定
session.gc_maxlifetime
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个人觉得每个请求是一个进程吧
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我留个痕迹
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对于内存占用的垃圾处理吗？
首先ＰＨＰ作为脚本语言是页面结束即释放变量所占内存的。
如果说有垃圾，那就是整体的程序在框架使用中，会多次调用同一文件等等造成的非单件模式等。
所以在出来的时候，必要的用_once 引用，在声明类的时候使用单件模式。还有简化逻辑等等。
而如果妄想让PHP自己本身管理内存，进行垃圾管理。呵呵。好像PHP还办不到，对于析构函数，ANDI在他的书里写的很明白。可有可无，不可置否。
而内存管理的东西一般都是桌面程序更多去考虑的。PHP还非要搞一个内存管理的东西，哎，鞭长莫及吧。
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学习
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呵呵~~，学习拉！
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不懂，看过JavaScript的垃圾回收机制，PHP还真没注意过！
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记得书上说用引用计数和写时复制来管理内存，也是PHP的内存管理的主要机制
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中国的招聘总是整那么多的名词，那么多的理论，开发的时候还要看具体的能力的
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