是setlocale线程安全的功能？ [英] Is setlocale thread-safe function?

问题描述

我需要更改线程中的区域设置，以正确地解析strtod（），我正在使用setlocale（）（C ++）。是线程安全吗？

更新：另一个问题。当我在main（）函数中调用setlocale（）时，它在其他例程中不会更深入。为什么？？？有很多代码，所以编写这个块是有问题的。

解决方案

您需要查阅所使用的任何实现的文档。 C ++目前没有指定任何关于线程的内容，因此它归结于实现（您还没有告诉我们）。

例如，我的Linux的帮助页面setlocale具有代码段：

此字符串可能会分配静态存储。

这不绝对表明它是线程不安全的，但我会非常警惕。 $ b

可能是最安全的事情（假设它不是线程安全的）将保护所有调用到code> setlocale 与互斥体，并具有特殊功能，可以按照以下方式格式化数字：

 声明互斥体
 curr = setlocale具体值
格式号到字符串
 setlocale到curr 
释放mutex 
返回字符串
  

I need to change locale in the thread to parse a double with strtod() correctly, I'm using setlocale() for this (C++). Is it thread safe?

Update: Another problem. When I invoke setlocale() in my main() function it doesn't affect in other routines deeper. Why??? There is a lot of code, so it's problematic to write the chunk.

解决方案

You need to consult the documentation for whatever implementation you're using. C++ doesn't currently specify anything about threads so it comes down to the implementation (which you haven't yet told us).

For example, my Linux manpage for setlocale has the snippet:

This string may be allocated in static storage.

which doesn't absolutely indicate that it's thread-unsafe but I'd be very wary. It's likely that calling it with NULL (i.e., querying) would be thread-safe but as soon as you have a thread modifying it, all bets are off.

Probably the safest thing to do (assuming it isn't thread-safe) would be to protect all calls to setlocale with a mutex and have a special function to format your numbers along the lines of:

claim mutex
curr = setlocale to specific value
format number to string
setlocale to curr
release mutex
return string

这篇关于是setlocale线程安全的功能？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！