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authorSteve Reinhardt <steve.reinhardt@amd.com>2010-08-17 05:06:22 -0700
committerSteve Reinhardt <steve.reinhardt@amd.com>2010-08-17 05:06:22 -0700
commit1fbe466345b43caabece9730c1f0456f1b57b82f (patch)
tree8285f10d6ab642649d74ae79909508679f264d54 /src/sim
parent0f8b5afd7ad82fda05c3ad42cda4f9046992428d (diff)
downloadgem5-1fbe466345b43caabece9730c1f0456f1b57b82f.tar.xz
sim: make Python Root object a singleton
Enforce that the Python Root SimObject is instantiated only once. The C++ Root object already panics if more than one is created. This change avoids the need to track what the root object is, since it's available from Root.getInstance() (if it exists). It's now redundant to have the user pass the root object to functions like instantiate(), checkpoint(), and restoreCheckpoint(), so that arg is gone. Users who use configs/common/Simulate.py should not notice.
Diffstat (limited to 'src/sim')
-rw-r--r--src/sim/Root.py25
1 files changed, 25 insertions, 0 deletions
diff --git a/src/sim/Root.py b/src/sim/Root.py
index fff998e0d..c7404a11f 100644
--- a/src/sim/Root.py
+++ b/src/sim/Root.py
@@ -28,7 +28,32 @@
from m5.SimObject import SimObject
from m5.params import *
+from m5.util import fatal
class Root(SimObject):
+
+ _the_instance = None
+
+ def __new__(cls, **kwargs):
+ if Root._the_instance:
+ fatal("Attempt to allocate multiple instances of Root.")
+ return None
+
+ # first call: allocate the unique instance
+ #
+ # If SimObject ever implements __new__, we may want to pass
+ # kwargs here, but for now this goes straight to
+ # object.__new__ which prints an ugly warning if you pass it
+ # args. Seems like a bad design but that's the way it is.
+ Root._the_instance = SimObject.__new__(cls)
+ return Root._the_instance
+
+ @classmethod
+ def getInstance(cls):
+ return Root._the_instance
+
+ def path(self):
+ return 'root'
+
type = 'Root'
dummy = Param.Int(0, "We don't support objects without params")