mlir/test/python/live_operations.py

   1 # RUN: %PYTHON %s
   2 # It is sufficient that this doesn't assert.
   3
   4 from mlir.ir import *
   5
   6
   7 def createDetachedModule():
   8     module = Module.create()
   9     with InsertionPoint(module.body):
  10         # TODO: Python bindings are currently unaware that modules are also
  11         # operations, so having a module erased won't trigger the cascading
  12         # removal of live operations (#93337). Use a non-module operation
  13         # instead.
  14         nested = Operation.create("test.some_operation", regions=1)
  15
  16         # When the operation is detached from parent, it is considered to be
  17         # owned by Python. It will therefore be erased when the Python object
  18         # is destroyed.
  19         nested.detach_from_parent()
  20
  21         # However, we create and maintain references to operations within
  22         # `nested`. These references keep the corresponding operations in the
  23         # "live" list even if they have been erased in C++, making them
  24         # "zombie". If the C++ allocator reuses one of the address previously
  25         # used for a now-"zombie" operation, this used to result in an
  26         # assertion "cannot create detached operation that already exists" from
  27         # the bindings code. Erasing the detached operation should result in
  28         # removing all nested operations from the live list.
  29         #
  30         # Note that the assertion is not guaranteed since it depends on the
  31         # behavior of the allocator on the C++ side, so this test mail fail
  32         # intermittently.
  33         with InsertionPoint(nested.regions[0].blocks.append()):
  34             a = [Operation.create("test.some_other_operation") for i in range(100)]
  35     return a
  36
  37
  38 def createManyDetachedModules():
  39     with Context() as ctx, Location.unknown():
  40         ctx.allow_unregistered_dialects = True
  41         for j in range(100):
  42             a = createDetachedModule()
  43
  44
  45 if __name__ == "__main__":
  46     createManyDetachedModules()