Utils: add an helper to increase opened file soft limit

src/silx/app/view/main.py

@@ -34,6 +34,7 @@
 import traceback
 
 from silx.app.utils import parseutils
+from silx.utils.system_limit import increase_max_opened_files
 
 _logger = logging.getLogger(__name__)
 """Module logger"""
@@ -102,20 +103,7 @@ def mainQt(options):
     # Import most of the things here to be sure to use the right logging level
     #
 
-    # Use max opened files hard limit as soft limit
-    try:
-        import resource
-    except ImportError:
-        _logger.debug("No resource module available")
-    else:
-        if hasattr(resource, "RLIMIT_NOFILE"):
-            try:
-                hard_nofile = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
-                resource.setrlimit(resource.RLIMIT_NOFILE, (hard_nofile, hard_nofile))
-            except (ValueError, OSError):
-                _logger.warning("Failed to retrieve and set the max opened files limit")
-            else:
-                _logger.debug("Set max opened files to %d", hard_nofile)
+    increase_max_opened_files()
 
     # This needs to be done prior to load HDF5
     hdf5_file_locking = "TRUE" if options.hdf5_file_locking else "FALSE"
@@ -131,10 +119,10 @@ def mainQt(options):
         )
 
     import silx
-    from silx.gui import qt
 
     # Make sure matplotlib is configured
     import silx.gui.utils.matplotlib  # noqa
+    from silx.gui import qt
 
     app = qt.QApplication.instance()
     if app is None:

src/silx/utils/system_limit.py

@@ -0,0 +1,49 @@
+# /*##########################################################################
+#
+# Copyright (c) 2019 European Synchrotron Radiation Facility
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+#
+# ###########################################################################*/
+"""Utils function relative to system limit"""
+
+__authors__ = ["M. Ruyer"]
+__license__ = "MIT"
+__date__ = "05/06/2026"
+
+import logging
+
+_logger = logging.getLogger()
+
+
+def increase_max_opened_files():
+    """Use max opened files hard limit as soft limit"""
+    try:
+        import resource
+    except ImportError:
+        _logger.debug("No resource module available")
+    else:
+        if hasattr(resource, "RLIMIT_NOFILE"):
+            try:
+                hard_nofile = resource.getrlimit(resource.RLIMIT_NOFILE)[1]
+                resource.setrlimit(resource.RLIMIT_NOFILE, (hard_nofile, hard_nofile))
+            except (ValueError, OSError):
+                _logger.warning("Failed to retrieve and set the max opened files limit")
+            else:
+                _logger.debug("Set max opened files to %d", hard_nofile)