Returns an interface that represents the singleton instance of the Concurrency Runtime's Resource Manager. The Resource Manager is responsible for assigning resources to schedulers that want to cooperate with each other.
Multiple subsequent calls to this method will return the same instance of the Resource Manager. Each call to the method increments a reference count on the Resource Manager, and must be matched with a call to the IResourceManager::Release method when your scheduler is done communicating with the Resource Manager.
unsupported_os is thrown if the operating system is not supported by the Concurrency Runtime.