def barrier(tag=0, sleep=0.01):
''' A better mpi barrier
The original MPI.comm.barrier() may cause idle processes to still occupy
the CPU, while this barrier waits.
'''
if SIZE == 1:
return
mask = 1
while mask < SIZE:
dst = (RANK + mask) % SIZE
src = (RANK - mask + SIZE) % SIZE
req = COMM.isend(None, dst, tag)
while not COMM.Iprobe(src, tag):
time.sleep(sleep)
COMM.recv(None, src, tag)
req.Wait()
mask <<= 1
def barrier(tag=0, sleep=0.01):
''' A better mpi barrier
The original MPI.comm.barrier() may cause idle processes to still occupy
the CPU, while this barrier waits.
'''
if SIZE == 1:
return
mask = 1
while mask < SIZE:
dst = (RANK + mask) % SIZE
src = (RANK - mask + SIZE) % SIZE
req = COMM.isend(None, dst, tag)
while not COMM.Iprobe(src, tag):
time.sleep(sleep)
COMM.recv(None, src, tag)
req.Wait()
mask <<= 1
def elect():
'''elect() randomly chooses a node from all the nodes as the president.
Input:
None
Output:
the rank of the president
'''
president = COMM.bcast(np.random.randint(SIZE))
return president
def elect():
'''elect() randomly chooses a node from all the nodes as the president.
Input:
None
Output:
the rank of the president
'''
president = COMM.bcast(np.random.randint(SIZE))
return president
def root_decide(decision):
"""Returns the root decision."""
return COMM.bcast(decision)
def mpi_all(decision):
"""the logical all() over all instances
"""
return all(COMM.allgather(decision))
def root_decide(decision):
"""Returns the root decision."""
return COMM.bcast(decision)
def mpi_all(decision):
"""the logical all() over all instances
"""
return all(COMM.allgather(decision))
from mpi4py import MPI
COMM = MPI.COMM_WORLD
_IS_DUMMY = False
except ImportError as error:
logging.warning(
"Warning: I cannot import mpi4py. Using a dummpy single noded "
"implementation instead. The program will run in single node mode "
"even if you executed me with mpirun or mpiexec.\n"
"\n"
"We STRONGLY recommend you to try to install mpi and "
"mpi4py.\n")
logging.warning("mpi4py exception message is: %s", error)
from decaf.util._mpi_dummy import COMM
_IS_DUMMY = True
RANK = COMM.Get_rank()
SIZE = COMM.Get_size()
HOST = socket.gethostname()
_MPI_PRINT_MESSAGE_TAG = 560710
_MPI_BUFFER_LIMIT = 2**30
# we need to set the random seed different for each mpi instance
logging.info('blop.util.mpi: seting different random seeds for each node.')
random.seed(time.time() * RANK)
def is_dummy():
'''Returns True if this is a dummy version of MPI.'''
return _IS_DUMMY
