Thread safety with heap-allocated memory

Question

I was reading this: http://en.wikipedia.org/wiki/Thread_safety

Is the following function thread-safe?

void foo(int y){
    int * x = new int[50];
    /*...         


        

Answer 1

If you are coding in an environment that supports multi-threading, then you can be pretty sure new is thread safe.

Although the memory is on the heap, the pointer to it is on the stack. Only your thread has the pointer to this memory, and so there is no risk of concurrent modification - no other thread knows where the memory is to modify it.

You would only get a problem with thread safety if you were to pass this pointer to another thread that would then concurrently modify this memory at the same time as your original (or another) thread.