Memory Management

The MSCCL++ stack handles most of the resource management automatically, so users don’t need to explicitly store or destroy objects constructed by MSCCL++ APIs in most cases. For example:

• The Context object will be alive iff itself or any Connections created by it are alive.

• The Connection object will be alive iff itself or any SemaphoreStubs created from it are alive.

• The SemaphoreStub object will be alive iff itself or any Semaphores created from it are alive.

• The Semaphore object will be alive iff itself or any Channels created from it are alive.

However, there are still a few things put on users’ responsibility:

• RegisteredMemory does not own the memory region it represents. Users need to ensure that the memory region is valid and accessible for the lifetime of the RegisteredMemory object.

• The objects that are serialized and sent to other processes (like Endpoint, SemaphoreStub, and RegisteredMemory) should be kept alive until the remote endpoint has finished using them.

• The channel objects on the host should be kept alive until the GPU kernels are finished using the device handles.