如何在OpenMP C ++中分配动态内存

Question

I tried to parallel function, that allocates memory, but I had an exception of bad heap. Memory must have used some threads in one time.

void GetDoubleParameters( CInd *ci )
{
    for(int i=0;i<ci->size();i++)
    {
        void *tmp;
        #pragma omp parallel private (tmp)
        {
            for(int j=0;j<ci[i].getValues().size();j++)
            {
                tmp = (void*)new double(ci[i].getValues()[j]);
                ci->getParameters().push_back(tmp);
            }
        }

    }
}

Answer 1

The problem is the line:

ci->getParameters().push_back(tmp);

ci is accessed by all parallel threads at once, and its parameters element with the push_back routine (probably a std::vector) is probably not thread-safe. You will have to organize some guards around this code. Something like:

omp_lock_t my_lock;
...
// initialize lock
omp_init_lock (&my_lock);
...

// do something sensible in parallel
  ...
  {
      omp_guard my_guard (my_lock);
      // protected region starts here
      // only one thread at a time works here
  }
  // more parallel work
  ...
}
omp_destroy_lock (&my_lock);