何时确切初始化在全局范围内声明的thread_local变量? [英] When exactly is a thread_local variable declared at global scope initialized?

问题描述

例如:

#include <thread>

thread_local int n = 1;

void f()
{
    ++n; // is n initialized here for each thread or prior to entering f()?
}

int main()
{
    std::thread ta(f);
    std::thread tb(f);

    ta.join();
    tb.join();
}

从此处何时初始化尚不清楚. >

It's still not entirely clear from here when is n initialized.

推荐答案

足够简单，并且都符合规范.每当运行新线程时，n都将被初始化-在您输入任何特定于线程的函数之前.

Simple enough, and all according to specification. n is going to be initialized whenever the new thread is run - before you enter any thread-specific functions.

确切地说，它将被初始化三次.

To be exact, it is going to be initialized three times.

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