def on_prune(self, fgraph, app, reason):
"""
Remove Apply instance from set which must be computed.
"""
if app not in self.debug_all_apps:
raise ProtocolError("prune without import")
self.debug_all_apps.remove(app)
# UPDATE self.clients
for i, input in enumerate(OrderedSet(app.inputs)):
del self.clients[input][app]
if getattr(app.op, 'destroy_map', OrderedDict()):
self.destroyers.remove(app)
# Note: leaving empty client dictionaries in the struct.
# Why? It's a pain to remove them. I think they aren't doing any harm, they will be
# deleted on_detach().
# UPDATE self.view_i, self.view_o
for o_idx, i_idx_list in iteritems(
getattr(app.op, 'view_map', OrderedDict())):
if len(i_idx_list) > 1:
# destroying this output invalidates multiple inputs
raise NotImplementedError()
o = app.outputs[o_idx]
i = app.inputs[i_idx_list[0]]
del self.view_i[o]
self.view_o[i].remove(o)
if not self.view_o[i]:
del self.view_o[i]
self.stale_droot = True
def register(self, name, obj, *tags):
# N.B. obj is not an instance of class Optimizer.
# It is an instance of a DB.In the tests for example,
# this is not always the case.
if not isinstance(obj, (DB, opt.Optimizer, opt.LocalOptimizer)):
raise TypeError('Object cannot be registered in OptDB', obj)
if name in self.__db__:
raise ValueError(
'The name of the object cannot be an existing'
' tag or the name of another existing object.', obj, name)
if self.name is not None:
tags = tags + (self.name, )
obj.name = name
# This restriction is there because in many place we suppose that
# something in the DB is there only once.
if obj.name in self.__db__:
raise ValueError('''You can\'t register the same optimization
multiple time in a DB. Tryed to register "%s" again under the new name "%s".
Use theano.gof.ProxyDB to work around that''' % (obj.name, name))
self.__db__[name] = OrderedSet([obj])
self._names.add(name)
self.__db__[obj.__class__.__name__].add(obj)
self.add_tags(name, *tags)
def orderings(self, fgraph):
"""
Return orderings induced by destructive operations.
Raise InconsistencyError when
a) attempting to destroy indestructable variable, or
b) attempting to destroy a value multiple times, or
c) an Apply destroys (illegally) one of its own inputs by aliasing
"""
rval = OrderedDict()
if self.destroyers:
# BUILD DATA STRUCTURES
# CHECK for multiple destructions during construction of variables
droot, impact, __ignore = self.refresh_droot_impact()
# check for destruction of constants
illegal_destroy = [r for r in droot if
getattr(r.tag, 'indestructible', False) or
isinstance(r, graph.Constant)]
if illegal_destroy:
raise InconsistencyError(
"Attempting to destroy indestructible variables: %s" %
illegal_destroy)
# add destroyed variable clients as computational dependencies
for app in self.destroyers:
# for each destroyed input...
for output_idx, input_idx_list in iteritems(app.op.destroy_map):
destroyed_idx = input_idx_list[0]
destroyed_variable = app.inputs[destroyed_idx]
root = droot[destroyed_variable]
root_impact = impact[root]
# we generally want to put all clients of things which depend on root
# as pre-requisites of app.
# But, app is itself one such client!
# App will always be a client of the node we're destroying
# (destroyed_variable, but the tricky thing is when it is also a client of
# *another variable* viewing on the root. Generally this is illegal, (e.g.,
# add_inplace(x, x.T). In some special cases though, the in-place op will
# actually be able to work properly with multiple destroyed inputs (e.g,
# add_inplace(x, x). An Op that can still work in this case should declare
# so via the 'destroyhandler_tolerate_same' attribute or
# 'destroyhandler_tolerate_aliased' attribute.
#
# destroyhandler_tolerate_same should be a list of pairs of the form
# [(idx0, idx1), (idx0, idx2), ...]
# The first element of each pair is the input index of a destroyed
# variable.
# The second element of each pair is the index of a different input where
# we will permit exactly the same variable to appear.
# For example, add_inplace.tolerate_same might be [(0,1)] if the destroyed
# input is also allowed to appear as the second argument.
#
# destroyhandler_tolerate_aliased is the same sort of list of
# pairs.
# op.destroyhandler_tolerate_aliased = [(idx0, idx1)] tells the
# destroyhandler to IGNORE an aliasing between a destroyed
# input idx0 and another input idx1.
# This is generally a bad idea, but it is safe in some
# cases, such as
# - the op reads from the aliased idx1 before modifying idx0
# - the idx0 and idx1 are guaranteed not to overlap (e.g.
# they are pointed at different rows of a matrix).
#
# CHECK FOR INPUT ALIASING
# OPT: pre-compute this on import
tolerate_same = getattr(app.op,
'destroyhandler_tolerate_same', [])
assert isinstance(tolerate_same, list)
tolerated = OrderedSet(idx1 for idx0, idx1 in tolerate_same
if idx0 == destroyed_idx)
tolerated.add(destroyed_idx)
tolerate_aliased = getattr(
app.op, 'destroyhandler_tolerate_aliased', [])
assert isinstance(tolerate_aliased, list)
ignored = OrderedSet(idx1 for idx0, idx1 in tolerate_aliased
if idx0 == destroyed_idx)
# print 'tolerated', tolerated
# print 'ignored', ignored
for i, input in enumerate(app.inputs):
if i in ignored:
continue
if input in root_impact \
and (i not in tolerated or
input is not destroyed_variable):
raise InconsistencyError("Input aliasing: %s (%i, %i)"
% (app, destroyed_idx, i))
# add the rule: app must be preceded by all other Apply instances that
# depend on destroyed_input
root_clients = OrderedSet()
for r in root_impact:
assert not [a for a, c in self.clients[r].items() if not c]
root_clients.update([a for a, c in self.clients[r].items() if c])
root_clients.remove(app)
if root_clients:
rval[app] = root_clients
return rval
def on_attach(self, fgraph):
"""
When attaching to a new fgraph, check that
1) This DestroyHandler wasn't already attached to some fgraph
(its data structures are only set up to serve one)
2) The FunctionGraph doesn't already have a DestroyHandler.
This would result in it validating everything twice, causing
compilation to be slower.
TODO: WRITEME: what does this do besides the checks?
"""
####### Do the checking ###########
already_there = False
if self.fgraph is fgraph:
already_there = True
if self.fgraph not in [None, fgraph]:
raise Exception("A DestroyHandler instance can only serve"
" one FunctionGraph. (Matthew 6:24)")
for attr in ('destroyers', 'destroy_handler'):
if hasattr(fgraph, attr):
already_there = True
if already_there:
# FunctionGraph.attach_feature catches AlreadyThere
# and cancels the attachment
raise toolbox.AlreadyThere(
"DestroyHandler feature is already present or in"
" conflict with another plugin.")
####### end of checking ############
def get_destroyers_of(r):
droot, impact, root_destroyer = self.refresh_droot_impact()
try:
return [root_destroyer[droot[r]]]
except Exception:
return []
fgraph.destroyers = get_destroyers_of
fgraph.destroy_handler = self
self.fgraph = fgraph
self.destroyers = OrderedSet(
) #set of Apply instances with non-null destroy_map
self.view_i = {} # variable -> variable used in calculation
self.view_o = {
} # variable -> set of variables that use this one as a direct input
#clients: how many times does an apply use a given variable
self.clients = {} # variable -> apply -> ninputs
self.stale_droot = True
# IG: It's unclear if this is meant to be included in deployed code. It looks like
# it is unnecessary if FunctionGraph is working correctly, so I am commenting uses
# of it (for speed) but leaving the commented code in place so it is easy to restore
# for debugging purposes.
# Note: is there anything like the C preprocessor for python? It would be useful to
# just ifdef these things out
# self.debug_all_apps = set()
if self.do_imports_on_attach:
toolbox.Bookkeeper.on_attach(self, fgraph)
def get_impact(root, view_o):
impact = OrderedSet()
add_impact(root, view_o, impact)
return impact
