golang 1.2.1的GC因为算法的问题,在实际应用过程中,对于长时间运行的daemon程序,确实很容易导致内存泄露,有人用cgo来手动管理内存,也有人用pool来管理buffer,这些都很麻烦,还是等1.3发布吧,在golang 1.2.1中,如果注意一些坑,还是很容易写出稳定运行的程序。
1. 避免递归;
2.在for里面,把一些每次重复的操作提到外面,比如包的init方法中执行, 这些不必多说,比如初始化一个数据库连接,regexp.Compile等;
3. 函数返回,对于slice本身是引用传递,struct等比较大的对象,用指针,在for循环里面用完将指针赋值为nil,这一点非常重要;
The garbage collector will collect memory your program no longer has a pointer to.
To avoid leaking memory you just need to avoid holding on to pointers to memory you're no longer interested in using.
4.注意一些错误的写法,比如:
func parseFile(file string) string {
f,err := os.Open(file)
defer f.Close()
if err != nil {
fmt.Println(err)
//os.Exit(1)
}
正确的写法是:
//os.Exit(1)
}else{
defer f.Close()
}
这个问题很多初学者容易犯,非常容易导致cpu消耗大,甚至报错;
5. 减少对象的创建,尽量使用数组,struct可用做链表;
6. runtime.GC()没有什么用,go每2分钟执行一次垃圾回收;
> What is it used for? It should use in what situation?
For example,before running a benchmark. But the runtime is free to
ignore the call or postpone performing the real GC to any later time
so it's a hint at best.
> It is useful to avoid memory leaks?
ones and also lower the total used memory - for some programs and it
may be a win for them.
See also: http://golang.org/pkg/runtime/
7. 程序写完跑一段时间,用go自带的性能分析工具pprof分析heap,cpu等,尽快发现问题;
8. 运行发现cpu消耗高,内存持续上涨怎么办, 写个程序定时killall,或者crontab执行,再慢慢调优;
原文:http://blog.csdn.net/yxw2014/article/details/22283039