DM-27894: Python multiprocessing fixes

fgcm/fgcmBrightObs.py

@@ -7,7 +7,6 @@
 from .fgcmChisq import FgcmChisq
 
 import multiprocessing
-from multiprocessing import Pool
 
 from .sharedNumpyMemManager import SharedNumpyMemManager as snmm
 
@@ -143,7 +142,8 @@ def brightestObsMeanMag(self,debug=False,computeSEDSlopes=False):
                                (nSections,time.time() - prepStartTime))
 
             # make a pool
-            pool = Pool(processes=self.nCore)
+            mp_ctx = multiprocessing.get_context("fork")
+            pool = mp_ctx.Pool(processes=self.nCore)
             pool.map(self._worker,workerList,chunksize=1)
             pool.close()
             pool.join()

fgcm/fgcmChisq.py

@@ -12,7 +12,6 @@
 from .fgcmNumbaUtilities import numba_test, add_at_1d, add_at_2d, add_at_3d
 
 import multiprocessing
-from multiprocessing import Pool
 
 from .sharedNumpyMemManager import SharedNumpyMemManager as snmm
 
@@ -325,8 +324,9 @@ def __call__(self,fitParams,fitterUnits=False,computeDerivatives=False,computeSE
         else:
             # regular multi-core
 
+            mp_ctx = multiprocessing.get_context('fork')
             # make a dummy process to discover starting child number
-            proc = multiprocessing.Process()
+            proc = mp_ctx.Process()
             workerIndex = proc._identity[0]+1
             proc = None
 
@@ -366,7 +366,7 @@ def __call__(self,fitParams,fitterUnits=False,computeDerivatives=False,computeSE
             self.fgcmLog.debug('Running chisq on %d cores' % (self.nCore))
 
             # make a pool
-            pool = Pool(processes=self.nCore)
+            pool = mp_ctx.Pool(processes=self.nCore)
             # Compute magnitudes
             pool.map(self._magWorker, workerList, chunksize=1)
 

fgcm/fgcmComputeStepUnits.py

@@ -9,7 +9,6 @@
 from .fgcmNumbaUtilities import numba_test, add_at_1d, add_at_2d, add_at_3d
 
 import multiprocessing
-from multiprocessing import Pool
 
 from .sharedNumpyMemManager import SharedNumpyMemManager as snmm
 
@@ -112,7 +111,8 @@ def run(self, fitParams):
         # going to have one or the other, and this doesn't care which is which
         self.nSums += 2 * self.fgcmPars.nFitPars
 
-        proc = multiprocessing.Process()
+        mp_ctx = multiprocessing.get_context("fork")
+        proc = mp_ctx.Process()
         workerIndex = proc._identity[0]+1
         proc = None
 
@@ -141,7 +141,7 @@ def run(self, fitParams):
         workerList.sort(key=lambda elt:elt[1].size, reverse=True)
 
         # make a pool
-        pool = Pool(processes=self.nCore)
+        pool = mp_ctx.Pool(processes=self.nCore)
         # Compute magnitudes
         pool.map(self._stepWorker, workerList, chunksize=1)
 

fgcm/fgcmFitCycle.py

@@ -36,16 +36,6 @@
 
 from .sharedNumpyMemManager import SharedNumpyMemManager as snmm
 
-import multiprocessing
-import platform
-
-
-# Fix for multiprocessing/matplotlib but on python <= 3.7 and macos >= 10.15
-if len(platform.mac_ver()[0]) > 0 and sys.version_info.major == 3 and sys.version_info.minor < 8:
-    parts = platform.mac_ver()[0].split('.')
-    if (int(parts[0]) > 10) or (int(parts[0]) == 10 and int(parts[0]) >= 15):
-        multiprocessing.set_start_method('forkserver')
-
 
 class FgcmFitCycle(object):
     """

fgcm/fgcmRetrieval.py

@@ -7,7 +7,6 @@
 import matplotlib.pyplot as plt
 
 import multiprocessing
-from multiprocessing import Pool
 
 from .sharedNumpyMemManager import SharedNumpyMemManager as snmm
 
@@ -149,7 +148,8 @@ def computeRetrievalIntegrals(self,debug=False):
             uExpIndexList = np.array_split(uExpIndex,nSections)
 
             # may want to sort by nObservations, but only if we pre-split
-            pool = Pool(processes=self.nCore)
+            mp_ctx = multiprocessing.get_context("fork")
+            pool = mp_ctx.Pool(processes=self.nCore)
             pool.map(self._worker, uExpIndexList, chunksize=1)
             pool.close()
             pool.join()

fgcm/fgcmSigmaCal.py

@@ -7,7 +7,6 @@
 from .fgcmUtilities import retrievalFlagDict
 
 import multiprocessing
-from multiprocessing import Pool
 
 from .sharedNumpyMemManager import SharedNumpyMemManager as snmm
 
@@ -183,7 +182,8 @@ def run(self, applyGray=True):
         for i, s in enumerate(sigmaCals):
             self.sigmaCal = s
 
-            pool = Pool(processes=self.nCore)
+            mp_ctx = multiprocessing.get_context("fork")
+            pool = mp_ctx.Pool(processes=self.nCore)
             pool.map(self._worker, workerList, chunksize=1)
             pool.close()
             pool.join()

fgcm/fgcmZpsToApply.py

@@ -5,7 +5,6 @@
 from .fgcmNumbaUtilities import numba_test, add_at_1d, add_at_2d, add_at_3d
 
 import multiprocessing
-from multiprocessing import Pool
 
 from .sharedNumpyMemManager import SharedNumpyMemManager as snmm
 
@@ -138,7 +137,8 @@ def applyZeropoints(self):
 
         goodStarsSub, goodObs = self.fgcmStars.getGoodObsIndices(goodStars, expFlag=self.fgcmPars.expFlag)
 
-        proc = multiprocessing.Process()
+        mp_ctx = multiprocessing.get_context('fork')
+        proc = mp_ctx.Process()
         workerIndex = proc._identity[0] + 1
         proc = None
 
@@ -157,7 +157,7 @@ def applyZeropoints(self):
 
         workerList.sort(key=lambda elt:elt[1].size, reverse=True)
 
-        pool = Pool(processes=self.nCore)
+        pool = mp_ctx.Pool(processes=self.nCore)
         pool.map(self._worker, workerList, chunksize=1)
 
         pool.close()