add comms doc

python/cugraph/comms/comms.py

@@ -9,16 +9,33 @@
 
 # Intialize Comms. If explicit Comms not provided as arg,
 # default Comms are initialized as per client information.
-def initialize(arg=None):
+def initialize(comms=None, p2p=False):
+    """
+    Intitializes a communicator for multi-node multi-gpu communications.
+    It is expected to be called right after client initialization for running
+    mnmg algorithms. It wraps raft comms that manages underlying NCCL and UCX
+    comms handles across the workers of a Dask cluster.
+    It is recommended to also call `destroy()` when the comms are no longer
+    needed so the underlying resources can be cleaned up.
+
+    Parameters
+    ----------
+    comms : raft Comms
+        A pre-initialized raft communicator. If provided, this is used for mnmg
+        communications.
+    p2p : bool
+        Initialize UCX endpoints
+    """
+
     global __instance
     if __instance is None:
         global __default_handle
         __default_handle = None
-        if arg is None:
-            __instance = raftComms()
+        if comms is None:
+            __instance = raftComms(comms_p2p=p2p)
             __instance.init()
         else:
-            __instance = arg
+            __instance = comms
     else:
         raise Exception("Communicator is already initialized")
 
@@ -47,6 +64,9 @@ def get_session_id():
 
 # Destroy Comms
 def destroy():
+    """
+    Shuts down initialized comms and cleans up resources.
+    """
     global __instance
     if is_initialized():
         __instance.destroy()