class Reorderer:
"""Reorders a partitioned mesh using Zoltan"""
def __init__(self, mesh, partition):
# First reorder the mesh, so partitions are no longer distributed
self.__partitionStart = []
sum = 0
for i in range(len(partition)):
self.__partitionStart.append(sum)
sum += partition.size(i)
nextPos = copy.copy(self.__partitionStart)
old2new = []
for p in partition:
old2new.append(nextPos[p])
nextPos[p] += 1
self.__mesh = ReorderedMesh(mesh, old2new)
self.__partition = ReorderedPartition(partition, old2new)
self.__old2new = [None] * len(self.__mesh.elements())
# Run Zoltan for every partition
for p in range(len(partition)):
self.__zoltanError = ''
try:
zoltan = subprocess.Popen(['mpiexec', '-n', '1',
os.path.join(os.path.dirname(__file__), 'zoltan', 'zoltan'),
str(partition.size(p))],
stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
except OSError:
raise Exception('Could not run mpiexec. Please provide correct $PATH')
threading.Thread(target=self.__feedElements, args=(zoltan.stdin, p)).start()
outThread = threading.Thread(target=self.__readZoltanOrder, args=(zoltan.stdout, p))
outThread.start()
errorThread = threading.Thread(target=self.__readZoltanError, args=(zoltan.stderr,))
errorThread.start()
if zoltan.wait():
errorThread.join()
raise Exception(self.__zoltanError.strip())
outThread.join()
errorThread.join()
# Create the reordered mesh
self.__mesh = ReorderedMesh(self.__mesh, self.__old2new)
def __feedElements(self, stdin, partition):
"""Writes the element coordinates to stdin of the zoltan process"""
for element in self.__mesh.elements()[self.__partitionStart[partition]:
self.__partitionStart[partition]+self.__partition.size(partition)]:
coords = [sum(c) / 4 for c in zip(self.__mesh.coords()[element[0]],
self.__mesh.coords()[element[1]], self.__mesh.coords()[element[2]],
self.__mesh.coords()[element[3]])]
try:
print >> stdin, coords[0], coords[1], coords[2]
except IOError:
# Something went wrong, zoltan should report an error to stderr
break
def __readZoltanOrder(self, stdout, partition):
"""Reads the Zoltan stdout stream and creates the ordering"""
for line in stdout:
try:
new, old = map(int, line.split())
self.__old2new[old+self.__partitionStart[partition]] = new+self.__partitionStart[partition]
except Exception:
# Something went wrong, we check for inconsistent values later
pass
def __readZoltanError(self, stderr):
"""Reads the Zoltan error stream"""
for line in stderr:
self.__zoltanError += line + os.linesep
def mesh(self):
return self.__mesh
def partition(self):
return self.__partition
class Reorderer:
"""Reorders a partitioned mesh using Zoltan"""
def __init__(self, mesh, partition):
# First reorder the mesh, so partitions are no longer distributed
self.__partitionStart = []
sum = 0
for i in range(len(partition)):
self.__partitionStart.append(sum)
sum += partition.size(i)
nextPos = copy.copy(self.__partitionStart)
old2new = []
for p in partition:
old2new.append(nextPos[p])
nextPos[p] += 1
self.__mesh = ReorderedMesh(mesh, old2new)
self.__partition = ReorderedPartition(partition, old2new)
self.__old2new = [None] * len(self.__mesh.elements())
# Run Zoltan for every partition
for p in range(len(partition)):
self.__zoltanError = ''
try:
zoltan = subprocess.Popen([
'mpiexec', '-n', '1',
os.path.join(os.path.dirname(__file__), 'zoltan',
'zoltan'),
str(partition.size(p))
],
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE)
except OSError:
raise Exception(
'Could not run mpiexec. Please provide correct $PATH')
threading.Thread(target=self.__feedElements,
args=(zoltan.stdin, p)).start()
outThread = threading.Thread(target=self.__readZoltanOrder,
args=(zoltan.stdout, p))
outThread.start()
errorThread = threading.Thread(target=self.__readZoltanError,
args=(zoltan.stderr, ))
errorThread.start()
if zoltan.wait():
errorThread.join()
raise Exception(self.__zoltanError.strip())
outThread.join()
errorThread.join()
# Create the reordered mesh
self.__mesh = ReorderedMesh(self.__mesh, self.__old2new)
def __feedElements(self, stdin, partition):
"""Writes the element coordinates to stdin of the zoltan process"""
for element in self.__mesh.elements(
)[self.__partitionStart[partition]:self.__partitionStart[partition] +
self.__partition.size(partition)]:
coords = [
sum(c) / 4 for c in zip(self.__mesh.coords()[element[0]],
self.__mesh.coords()[element[1]],
self.__mesh.coords()[element[2]],
self.__mesh.coords()[element[3]])
]
try:
print >> stdin, coords[0], coords[1], coords[2]
except IOError:
# Something went wrong, zoltan should report an error to stderr
break
def __readZoltanOrder(self, stdout, partition):
"""Reads the Zoltan stdout stream and creates the ordering"""
for line in stdout:
try:
new, old = map(int, line.split())
self.__old2new[old + self.__partitionStart[
partition]] = new + self.__partitionStart[partition]
except Exception:
# Something went wrong, we check for inconsistent values later
pass
def __readZoltanError(self, stderr):
"""Reads the Zoltan error stream"""
for line in stderr:
self.__zoltanError += line + os.linesep
def mesh(self):
return self.__mesh
def partition(self):
return self.__partition
