OpenMP strange behaviour

Hello I have the following code, which I compile with gcc (>4.2) with -fopenmp flag:

int main(void)
{
#pragma omp parallel for
    int i; 
    for(i=0;i<4;i++) while(1);

    return 0;
}

I get a SIGSEGV on OSX Lion (ver 1.7.3, llvm-gcc 4.2.1) and CentOS 6.2 . What am I doing wrong here? Thanks

---

Not sure if this is relevant to the compiler version and configuration but while(true){} terminates

More precisely, if you write a loop which

makes no calls to library I/O functions, and

does not access or modify volatile objects, and

performs no synchronization operations (1.10) or atomic operations (Clause 29)

and does not terminate, you have undefined behaviour.

This may end up not applying to your situation, but as C++11 becomes more established, watch out.

---

Very interesting.

I changed the code a little so

int main(void)
{
int i;
#pragma omp parallel 
  {
        while(1);
    }
    return 0;
} 

and so

inline void func() {
    while (1) ;
}

int main(void)
{
int i;
#pragma omp parallel for 
    for(i=0;i<8;i++) {
        func();
    }
    return 0;
}

And they both worked OK.

---

There was a bug in the gcc regarding this issue, I reported it and they will provide a fix. Here is the link: GCC bug

链接地址: http://www.djcxy.com/p/57374.html

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