250 lines
6.5 KiB
Python

"""Distributed XGBoost Rabit related API."""
import ctypes
from enum import IntEnum, unique
import logging
import pickle
from typing import Any, TypeVar, Callable, Optional, cast, List, Union
import numpy as np
from .core import _LIB, c_str, _check_call
LOGGER = logging.getLogger("[xgboost.rabit]")
def _init_rabit() -> None:
"""internal library initializer."""
if _LIB is not None:
_LIB.RabitGetRank.restype = ctypes.c_int
_LIB.RabitGetWorldSize.restype = ctypes.c_int
_LIB.RabitIsDistributed.restype = ctypes.c_int
_LIB.RabitVersionNumber.restype = ctypes.c_int
def init(args: Optional[List[bytes]] = None) -> None:
"""Initialize the rabit library with arguments"""
if args is None:
args = []
arr = (ctypes.c_char_p * len(args))()
arr[:] = cast(List[Union[ctypes.c_char_p, bytes, None, int]], args)
_LIB.RabitInit(len(arr), arr)
def finalize() -> None:
"""Finalize the process, notify tracker everything is done."""
_LIB.RabitFinalize()
def get_rank() -> int:
"""Get rank of current process.
Returns
-------
rank : int
Rank of current process.
"""
ret = _LIB.RabitGetRank()
return ret
def get_world_size() -> int:
"""Get total number workers.
Returns
-------
n : int
Total number of process.
"""
ret = _LIB.RabitGetWorldSize()
return ret
def is_distributed() -> int:
'''If rabit is distributed.'''
is_dist = _LIB.RabitIsDistributed()
return is_dist
def tracker_print(msg: Any) -> None:
"""Print message to the tracker.
This function can be used to communicate the information of
the progress to the tracker
Parameters
----------
msg : str
The message to be printed to tracker.
"""
if not isinstance(msg, str):
msg = str(msg)
is_dist = _LIB.RabitIsDistributed()
if is_dist != 0:
_check_call(_LIB.RabitTrackerPrint(c_str(msg)))
else:
print(msg.strip(), flush=True)
def get_processor_name() -> bytes:
"""Get the processor name.
Returns
-------
name : str
the name of processor(host)
"""
mxlen = 256
length = ctypes.c_ulong()
buf = ctypes.create_string_buffer(mxlen)
_LIB.RabitGetProcessorName(buf, ctypes.byref(length), mxlen)
return buf.value
T = TypeVar("T") # pylint:disable=invalid-name
def broadcast(data: T, root: int) -> T:
"""Broadcast object from one node to all other nodes.
Parameters
----------
data : any type that can be pickled
Input data, if current rank does not equal root, this can be None
root : int
Rank of the node to broadcast data from.
Returns
-------
object : int
the result of broadcast.
"""
rank = get_rank()
length = ctypes.c_ulong()
if root == rank:
assert data is not None, 'need to pass in data when broadcasting'
s = pickle.dumps(data, protocol=pickle.HIGHEST_PROTOCOL)
length.value = len(s)
# run first broadcast
_check_call(_LIB.RabitBroadcast(ctypes.byref(length),
ctypes.sizeof(ctypes.c_ulong), root))
if root != rank:
dptr = (ctypes.c_char * length.value)()
# run second
_check_call(_LIB.RabitBroadcast(ctypes.cast(dptr, ctypes.c_void_p),
length.value, root))
data = pickle.loads(dptr.raw)
del dptr
else:
_check_call(_LIB.RabitBroadcast(ctypes.cast(ctypes.c_char_p(s), ctypes.c_void_p),
length.value, root))
del s
return data
# enumeration of dtypes
DTYPE_ENUM__ = {
np.dtype('int8'): 0,
np.dtype('uint8'): 1,
np.dtype('int32'): 2,
np.dtype('uint32'): 3,
np.dtype('int64'): 4,
np.dtype('uint64'): 5,
np.dtype('float32'): 6,
np.dtype('float64'): 7
}
@unique
class Op(IntEnum):
'''Supported operations for rabit.'''
MAX = 0
MIN = 1
SUM = 2
OR = 3
def allreduce( # pylint:disable=invalid-name
data: np.ndarray, op: Op, prepare_fun: Optional[Callable[[np.ndarray], None]] = None
) -> np.ndarray:
"""Perform allreduce, return the result.
Parameters
----------
data :
Input data.
op :
Reduction operators, can be MIN, MAX, SUM, BITOR
prepare_fun :
Lazy preprocessing function, if it is not None, prepare_fun(data)
will be called by the function before performing allreduce, to initialize the data
If the result of Allreduce can be recovered directly,
then prepare_fun will NOT be called
Returns
-------
result :
The result of allreduce, have same shape as data
Notes
-----
This function is not thread-safe.
"""
if not isinstance(data, np.ndarray):
raise Exception('allreduce only takes in numpy.ndarray')
buf = data.ravel()
if buf.base is data.base:
buf = buf.copy()
if buf.dtype not in DTYPE_ENUM__:
raise Exception(f"data type {buf.dtype} not supported")
if prepare_fun is None:
_check_call(_LIB.RabitAllreduce(buf.ctypes.data_as(ctypes.c_void_p),
buf.size, DTYPE_ENUM__[buf.dtype],
int(op), None, None))
else:
func_ptr = ctypes.CFUNCTYPE(None, ctypes.c_void_p)
def pfunc(_: Any) -> None:
"""prepare function."""
fn = cast(Callable[[np.ndarray], None], prepare_fun)
fn(data)
_check_call(_LIB.RabitAllreduce(buf.ctypes.data_as(ctypes.c_void_p),
buf.size, DTYPE_ENUM__[buf.dtype],
op, func_ptr(pfunc), None))
return buf
def version_number() -> int:
"""Returns version number of current stored model.
This means how many calls to CheckPoint we made so far.
Returns
-------
version : int
Version number of currently stored model
"""
ret = _LIB.RabitVersionNumber()
return ret
class RabitContext:
"""A context controlling rabit initialization and finalization."""
def __init__(self, args: List[bytes] = None) -> None:
if args is None:
args = []
self.args = args
def __enter__(self) -> None:
init(self.args)
assert is_distributed()
LOGGER.debug("-------------- rabit say hello ------------------")
def __exit__(self, *args: List) -> None:
finalize()
LOGGER.debug("--------------- rabit say bye ------------------")
# initialization script
_init_rabit()