Expose the CPU count of execution contexts

executor/__init__.py

@@ -60,7 +60,7 @@
 )
 
 # Semi-standard module versioning.
-__version__ = '4.3'
+__version__ = '4.4'
 
 # Initialize a logger.
 logger = logging.getLogger(__name__)

executor/contexts.py

@@ -62,6 +62,7 @@ def details_about_system(context):
 
 # Standard library modules.
 import logging
+import multiprocessing
 import socket
 
 # Modules included in our package.
@@ -259,6 +260,11 @@ def start_interactive_shell(self, **options):
         cmd.start()
         return cmd
 
+    @property
+    def cpu_count(self):
+        """The number of CPUs in the system (an integer)."""
+        raise NotImplementedError()
+
     def __enter__(self):
         self.undo_stack.append([])
         return self
@@ -274,6 +280,10 @@ class LocalContext(AbstractContext):
 
     """Context for executing commands on the local system."""
 
+    @property
+    def cpu_count(self):
+        return multiprocessing.cpu_count()
+
     def prepare_command(self, command, options):
         return ExternalCommand(*command, **self.merge_options(options))
 
@@ -297,6 +307,10 @@ def __init__(self, ssh_alias, **options):
         super(RemoteContext, self).__init__(**options)
         self.ssh_alias = ssh_alias
 
+    @property
+    def cpu_count(self):
+        return int(self.capture('nproc'))
+
     def prepare_command(self, command, options):
         return RemoteCommand(self.ssh_alias, *command, **self.merge_options(options))