Merge pull request #118 from lsst/tickets/DM-42799

Turn off implicit multithreading via env vars for all uses of sconsUtils

Author: erykoff

python/lsst/sconsUtils/state.py

@@ -187,33 +187,49 @@ def _initEnvironment():
     """Construction and basic setup of the state.env variable."""
 
     ourEnv = {}
-    preserveVars = """
-      DYLD_LIBRARY_PATH
-      EUPS_DIR
-      EUPS_LOCK_PID
-      EUPS_PATH
-      EUPS_SHELL
-      EUPS_USERDATA
-      LD_LIBRARY_PATH
-      PATH
-      SHELL
-      TEMP
-      TERM
-      TMP
-      TMPDIR
-      XPA_PORT
-      CONDA_BUILD_SYSROOT
-      SDKROOT
-    """.split()
-
-    codeCheckerVars = """
-      LD_PRELOAD
-      CC_LOGGER_FILE
-      CC_LOGGER_GCC_LIKE
-      CC_LIB_DIR
-      CC_DATA_FILES_DIR
-      CC_LOGGER_BIN
-    """.split()
+    preserveVars = [
+        "DYLD_LIBRARY_PATH",
+        "EUPS_DIR",
+        "EUPS_LOCK_PID",
+        "EUPS_PATH",
+        "EUPS_SHELL",
+        "EUPS_USERDATA",
+        "LD_LIBRARY_PATH",
+        "PATH",
+        "SHELL",
+        "TEMP",
+        "TERM",
+        "TMP",
+        "TMPDIR",
+        "XPA_PORT",
+        "CONDA_BUILD_SYSROOT",
+        "SDKROOT",
+    ]
+
+    codeCheckerVars = [
+        "LD_PRELOAD",
+        "CC_LOGGER_FILE",
+        "CC_LOGGER_GCC_LIKE",
+        "CC_LIB_DIR",
+        "CC_DATA_FILES_DIR",
+        "CC_LOGGER_BIN",
+    ]
+
+    # The list of implicit multithreading environment variables here
+    # is taken from lsst.utils.disable_implicit_threading(), but
+    # has to be put here for dependency ordering reasons, and
+    # to ensure these are set prior to any instantiation of pytest
+    # or any code that may implicitly spawn threads.
+    implicitMultithreadingVars = [
+        "OPENBLAS_NUM_THREADS",
+        "GOTO_NUM_THREADS",
+        "OMP_NUM_THREADS",
+        "MKL_NUM_THREADS",
+        "MKL_DOMAIN_NUM_THREADS",
+        "MPI_NUM_THREADS",
+        "NUMEXPR_NUM_THREADS",
+        "NUMEXPR_MAX_THREADS",
+    ]
 
     for key in preserveVars:
         if key in os.environ:
@@ -225,6 +241,10 @@ def _initEnvironment():
             if key in os.environ:
                 ourEnv[key] = os.environ[key]
 
+    # Turn off implicit multithreading.
+    for key in implicitMultithreadingVars:
+        ourEnv[key] = "1"
+
     # Find and propagate EUPS environment variables.
     cfgPath = []
     for k in os.environ:

python/lsst/sconsUtils/tools/cuda.py

@@ -52,9 +52,9 @@ def generate(env):
     env["NVCCCMDLINE"] = ""
 
     # default NVCC commands
-    env[
-        "STATICNVCCCMD"
-    ] = "$NVCC -o $TARGET -c $NVCCFLAGS $_CPPINCFLAGS $STATICNVCCFLAGS $NVCCCMDLINE $SOURCES"
+    env["STATICNVCCCMD"] = (
+        "$NVCC -o $TARGET -c $NVCCFLAGS $_CPPINCFLAGS $STATICNVCCFLAGS $NVCCCMDLINE $SOURCES"
+    )
     env["SHAREDNVCCCMD"] = (
         "$NVCC -o $TARGET -c $NVCCFLAGS $_CPPINCFLAGS $SHAREDNVCCFLAGS"
         " $ENABLESHAREDNVCCFLAG $NVCCCMDLINE $SOURCES"

python/lsst/sconsUtils/vcs/git.py

@@ -5,6 +5,7 @@
 If ever we want to do anything clever, we should use one of
 the supported python packages
 """
+
 import os
 
 from .. import state, utils

python/lsst/sconsUtils/vcs/hg.py

@@ -5,6 +5,7 @@
 If ever we want to do anything clever, we should use one of
 the supported svn/python packages
 """
+
 import os
 import re
 

python/lsst/sconsUtils/vcs/svn.py

@@ -3,6 +3,7 @@
 If ever we want to do anything clever, we should use one of
 the supported svn/python packages
 """
+
 import os
 import re
 import sys

tests/test_simple.py

@@ -21,6 +21,22 @@ def testEnvironment(self):
         self.assertIn(envVar, os.environ)
         self.assertTrue(os.path.exists(os.environ[envVar]), f"Check path {os.environ[envVar]}")
 
+    def testNoImplicitMultithreading(self):
+        """Test that the environment has turned off implicit
+        multithreading.
+        """
+        envVar = "OMP_NUM_THREADS"
+        self.assertIn(envVar, os.environ)
+        self.assertEqual(os.environ[envVar], "1")
+
+        try:
+            import numexpr
+        except ImportError:
+            numexpr = None
+
+        if numexpr:
+            self.assertEqual(numexpr.utils.get_num_threads(), 1)
+
 
 if __name__ == "__main__":
     unittest.main()