RF limiting within get_fdmax into something more sensible

billiard/compat.py

@@ -3,6 +3,7 @@
 import os
 import subprocess
 import sys
+import warnings
 
 from itertools import zip_longest
 
@@ -100,36 +101,34 @@ def get_fdmax(default=None):
                       descriptor limit.
 
     """
-    # Some system might be "mis"configured and allow for ulimit -n
-    # of e.g. 1073741816 which would be infeasible to sweep through.
-    def _get_fdmax():
-        try:
-            return os.sysconf('SC_OPEN_MAX')
-        except:
-            pass
+
+    try:
+        fdmax = os.sysconf('SC_OPEN_MAX')
+    except:
+        fdmax = None
+
+    if not fdmax:
         if resource is None:  # Windows
             return default
         fdmax = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
         if fdmax == resource.RLIM_INFINITY:
             return default
-        return fdmax
-
-    value = _get_fdmax()
-    if value != default and value >= 1e5 :
+    # Some system might be "mis"configured and allow for ulimit -n
+    # of e.g. 1073741816 which would be infeasible to sweep through.
+    if fdmax >= 1e5:
         # limiting value is ad-hoc and already more than sensible
-        import warnings
         if default:
-            new_value = default
-            msg = "default"
+            fdmax_limited = default
+            msg = "the default"
         else:
-            new_value = 10000
-            msg = "new smaller"
+            fdmax_limited = 10000
+            msg = "a new smaller"
         warnings.warn(UserWarning(
-           f"System set max number of open files is way too high and set to {value}."
-           f"Will use {msg} value of {new_value}"))
-        return new_value
+           f"System set max number of open files ({fdmax}) is way too high. "
+           f"Will use {msg} value of {fdmax_limited}"))
+        return fdmax_limited
     else:
-        return value
+        return fdmax
 
 
 def uniq(it):