Is shared_ptr::reset() lock-free?

Question

Imagine the following:

// SECTION A
MyClass* object = new MyClass();
std::shared_ptr<void> sharedObject;

// SECTION B (sharedObject is empty)
sharedObject.reset(object);

Is section B lock-free for an empty sharedObject? Or does it depend of the implementation?

Answer 1

This depends on implementation.

Some pointers:

1. Overhead and implementation of using shared_ptr
2. Linking pthread disables lock-free shared_ptr implementation