# 关于Nodejs中Buffer释放的二三事 - fengmk2

# 关于Nodejs中Buffer释放的二三事

## Buffer不会被GC？

为了看看这个问题，我写了一段测试代码

```js
var http = require("http"),
  os = require("os");

function create(size, res) {
  var mb = 1024 * 1024;
  res.write("free " + os.freemem() / mb + "MB\r\n");
  res.write("------------- after new " + size + "MB buffer\r\n");
  var buffer = new Buffer(size * mb);
  for (var i = 0, len = buffer.length; i < len; i++) {
    buffer[i] = 0;
  }
  res.write("free " + os.freemem() / mb + "MB\r\n\r\n");
}

http
  .createServer(function (req, res) {
    var size = 1;
    for (var i = 0; i < 100; i++) {
      res.write("------------- new Buffer " + i + "\r\n");
      create(size, res);
    }
    res.end("");
  })
  .listen("8080");
```

从[http://localhost:8080/](http://localhost:8080/)可以看到，一次http请求调用后

```
------------- new Buffer 0
free 139.82421875MB
------------- after new 1MB buffer
free 138.890625MB

------------- new Buffer 1
free 138.890625MB
------------- after new 1MB buffer
free 138.890625MB

------------- new Buffer 2
free 138.890625MB
------------- after new 1MB buffer
free 138.93359375MB

------------- new Buffer 3
free 138.93359375MB
------------- after new 1MB buffer
free 138.98046875MB

------------- new Buffer 4
free 138.98046875MB
------------- after new 1MB buffer
free 139.0703125MB

------------- new Buffer 5
free 139.0703125MB
------------- after new 1MB buffer
free 139.09375MB

***** 此处省略 *******

------------- new Buffer 96
free 136.90234375MB
------------- after new 1MB buffer
free 136.15234375MB

------------- new Buffer 97
free 136.1796875MB
------------- after new 1MB buffer
free 134.49609375MB

------------- new Buffer 98
free 134.515625MB
------------- after new 1MB buffer
free 133.64453125MB

------------- new Buffer 99
free 133.64453125MB
------------- after new 1MB buffer
free 132.76171875MB
```

从结果看来，Buffer会被回收。

## 疑问?

Buffer的实现是内存复用？还是说每次都重新申请和GC时释放给操作系统呢？

## 有爱

^\_^ 希望本文对你有用