def validate(self, fgraph):
"""Return None
Raise InconsistencyError when
a) orderings() raises an error
b) orderings cannot be topologically sorted.
"""
if self.destroyers:
ords = self.orderings(fgraph)
if _contains_cycle(fgraph, ords):
raise InconsistencyError("Dependency graph contains cycles")
else:
#James's Conjecture:
#If there are no destructive ops, then there can be no cycles.
#FB: This isn't always True. It can happend that
#optimization introduce node that depend on itself. This
#is very rare and should not happen in general. It will be
#caught later. The error will be far from the source. But
#doing this conjecture should speed up compilation most of
#the time. The user should create such dependency except
#if he mess too much with the internal.
pass
return True
def _build_droot_impact(self):
droot = {} # destroyed view + nonview variables -> foundation
impact = {} # destroyed nonview variable -> it + all views of it
root_destroyer = {} # root -> destroyer apply
for app in self.destroyers:
for output_idx, input_idx_list in app.op.destroy_map.items():
if len(input_idx_list) != 1:
raise NotImplementedError()
input_idx = input_idx_list[0]
input = app.inputs[input_idx]
input_root = getroot(input, self.view_i)
if input_root in droot:
raise InconsistencyError("Multiple destroyers of %s" %
input_root)
droot[input_root] = input_root
root_destroyer[input_root] = app
#input_impact = set([input_root])
#add_impact(input_root, self.view_o, input_impact)
input_impact = get_impact(input_root, self.view_o)
for v in input_impact:
assert v not in droot
droot[v] = input_root
impact[input_root] = input_impact
impact[input_root].add(input_root)
return droot, impact, root_destroyer
def refresh_droot_impact(self):
"""
Makes sure self.droot, self.impact, and self.root_destroyer are
up to date, and returns them.
(see docstrings for these properties above)
"""
if self.stale_droot:
droot = OrderedDict(
) # destroyed view + nonview variables -> foundation
impact = OrderedDict(
) # destroyed nonview variable -> it + all views of it
root_destroyer = OrderedDict() # root -> destroyer apply
for app in self.destroyers:
for output_idx, input_idx_list in app.op.destroy_map.items():
if len(input_idx_list) != 1:
raise NotImplementedError()
input_idx = input_idx_list[0]
input = app.inputs[input_idx]
input_root = getroot(input, self.view_i)
if input_root in droot:
raise InconsistencyError("Multiple destroyers of %s" %
input_root)
droot[input_root] = input_root
root_destroyer[input_root] = app
input_impact = get_impact(input_root, self.view_o)
for v in input_impact:
assert v not in droot
droot[v] = input_root
impact[input_root] = input_impact
impact[input_root].add(input_root)
self.droot, self.impact, self.root_destroyer = droot, impact, root_destroyer
self.stale_droot = False
return self.droot, self.impact, self.root_destroyer
def validate(self, fgraph):
"""Return None
Raise InconsistencyError when
a) orderings() raises an error
b) orderings cannot be topologically sorted.
"""
if self.destroyers:
ords = self.orderings(fgraph)
if _contains_cycle(fgraph, ords):
raise InconsistencyError("Dependency graph contains cycles")
else:
#James's Conjecture:
#If there are no destructive ops, then there can be no cycles.
pass
return True
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 app.op.destroy_map.items():
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