misc: Add deviceid to configuration and enhance switchconfig

devito/__init__.py

@@ -50,6 +50,7 @@ def reinit_compiler(val):
     """
     configuration['compiler'].__init__(suffix=configuration['compiler'].suffix,
                                        mpi=configuration['mpi'])
+    return val
 
 
 # Setup target platform and compiler
@@ -95,6 +96,9 @@ def reinit_compiler(val):
 # Enable/disable automatic padding for allocated data
 configuration.add('autopadding', False, [False, True])
 
+# Select target device
+configuration.add('deviceid', -1, preprocessor=int, impacts_jit=False)
+
 
 def autotune_callback(val):  # noqa
     if isinstance(val, str):

devito/arch/compiler.py

@@ -216,6 +216,10 @@ def __new_with__(self, **kwargs):
                               mpi=kwargs.pop('mpi', configuration['mpi']),
                               **kwargs)
 
+    @property
+    def name(self):
+        return self.__class__.__name__
+
     @memoized_meth
     def get_jit_dir(self):
         """A deterministic temporary directory for jit-compiled objects."""

devito/logger.py

@@ -56,6 +56,8 @@ def _set_log_level(level):
 
     logger.setLevel(level)
 
+    return level
+
 
 def set_log_level(level, comm=None):
     """

devito/operator/operator.py

@@ -1186,7 +1186,9 @@ def parse_kwargs(**kwargs):
 
     # `allocator`
     kwargs['allocator'] = default_allocator(
-        '%s.%s' % (kwargs['compiler'].__class__.__name__, kwargs['language'])
+        '%s.%s.%s' % (kwargs['compiler'].name,
+                      kwargs['language'],
+                      kwargs['platform'])
     )
 
     return kwargs

devito/parameters.py

@@ -72,15 +72,6 @@ def _preprocess(self, key, value):
         else:
             return value
 
-    def _updated(self, key, value):
-        """
-        Execute the callback associated to ``key``, if any.
-        """
-        if key in self._update_functions:
-            retval = self._update_functions[key](value)
-            if retval is not None:
-                super(Parameters, self).__setitem__(key, retval)
-
     @_check_key_deprecation
     def __getitem__(self, key, *args):
         return super(Parameters, self).__getitem__(key)
@@ -89,8 +80,10 @@ def __getitem__(self, key, *args):
     @_check_key_value
     def __setitem__(self, key, value):
         value = self._preprocess(key, value)
-        super(Parameters, self).__setitem__(key, value)
-        self._updated(key, value)
+        if key in self._update_functions:
+            value = self._update_functions[key](value)
+        if value is not None:
+            super(Parameters, self).__setitem__(key, value)
 
     @_check_key_deprecation
     @_check_key_value
@@ -232,31 +225,35 @@ def init_configuration(configuration=configuration, env_vars_mapper=env_vars_map
 class switchconfig(object):
 
     """
-    Decorator to temporarily change `configuration` parameters.
+    Decorator or context manager to temporarily change `configuration` parameters.
     """
 
     def __init__(self, condition=True, **params):
         if condition:
             self.params = {k.replace('_', '-'): v for k, v in params.items()}
         else:
             self.params = {}
+        self.previous = {}
+
+    def __enter__(self, condition=True, **params):
+        self.previous = {}
+        for k, v in self.params.items():
+            self.previous[k] = configuration[k]
+            configuration[k] = v
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        for k, v in self.params.items():
+            try:
+                configuration.update(k, self.previous[k])
+            except ValueError:
+                # E.g., `platform` and `compiler` will end up here
+                super(Parameters, configuration).__setitem__(k, self.previous[k])
 
     def __call__(self, func, *args, **kwargs):
         @wraps(func)
         def wrapper(*args, **kwargs):
-            previous = {}
-            for k, v in self.params.items():
-                previous[k] = configuration[k]
-                configuration[k] = v
-            try:
+            with self:
                 result = func(*args, **kwargs)
-            finally:
-                for k, v in self.params.items():
-                    try:
-                        configuration[k] = previous[k]
-                    except ValueError:
-                        # E.g., `platform` and `compiler` will end up here
-                        configuration[k] = previous[k].name
             return result
         return wrapper
 

devito/types/parallel.py

@@ -254,6 +254,14 @@ class DeviceID(DeviceSymbol):
     def default_value(self):
         return -1
 
+    def _arg_values(self, **kwargs):
+        if self.name in kwargs:
+            return {self.name: kwargs.pop(self.name)}
+        elif configuration['deviceid'] != self.default_value:
+            return {self.name: configuration['deviceid']}
+        else:
+            return {self.name: self.default_value}
+
 
 class DeviceRM(DeviceSymbol):