pybind11/tests/test_class_sh_trampoline_shared_from_this.py
Ralf W. Grosse-Kunstleve 48f25275c4
[smart_holder] Bake smart_holder functionality into class_ and type_caster_base (#5257)
* Put bakein branch @ 18b72c0ffa on top of smart_holder branch:

Commands used:

```
git checkout bakein
git diff smart_holder > ~/zd
git checkout smart_holder
git checkout -b bakein_sh
patch -p 1 < ~/zd
git checkout smart_holder \
MANIFEST.in \
README.rst \
README_smart_holder.rst \
docs/advanced/smart_ptrs.rst \
ubench/holder_comparison.cpp \
ubench/holder_comparison.py \
ubench/holder_comparison_extract_sheet_data.py \
ubench/number_bucket.h \
ubench/python/number_bucket.clif
git add -A
```

* Add back README_smart_holder.rst in tests/extra_python_package/test_files.py

* Restore smart_holder_poc.h as-is on smart_holder branch (i.e. undo `PYBIND11_SMART_HOLDER_PADDING`, which was meant for stress-testing only).

* Insert `std::move()` as suggested by @laramiel

* `property_cpp_function_sh_*` named specializations, as suggested by @laramiel (https://github.com/pybind/pybind11/pull/5257#discussion_r1688346807)

* Call `property_cpp_function_classic` member functions, rather than inlining the implementations.

* Use `PYBIND11_HAVE_INTERNALS_WITH_SMART_HOLDER_SUPPORT` in holder_comparison.cpp (holder_comparison.py is NOT changed accordingly in this commit, i.e. can still only be run if the smart_holder functionality is available).

* Systematically rename `loaded_as` to `load_as` (`shared_ptr`, `unique_ptr`) as suggested by @laramiel

* Make change as suggested by @laramiel. This makes it much more obvious that the latest implementation of `smart_holder_from_unique_ptr()` accepts all existing `return_value_policy` enum values except `copy`.

* Resolve `BAKEIN_WIP: Rewrite comment.` for `property_cpp_function_*` specializations.

* Resolve `BAKEIN_WIP: Add comment to explain: This is meant for stress-testing only.`

* Resolve all remaining BAKEIN_WIP (in pybind11/cast.h).

Leave only two pairs of SMART_HOLDER_BAKEIN_FOLLOW_ON comments: refactoring of copyable_holder_caster, move_only_holder_caster. This is best left until after the smart_holder branch is merged into the master branch.

* Remove obsolete `using holder_type = smart_holder;` in `load_helper`

* Add SMART_HOLDER_BAKEIN_FOLLOW_ON comment for `internals::default_holder`

* README_smart_holder.rst update (line count reduced from 356 to 123).
2024-07-31 06:17:31 -07:00

248 lines
8.1 KiB
Python

from __future__ import annotations
import sys
import weakref
import pytest
import env
import pybind11_tests.class_sh_trampoline_shared_from_this as m
if not m.defined_PYBIND11_HAVE_INTERNALS_WITH_SMART_HOLDER_SUPPORT:
pytest.skip("smart_holder not available.", allow_module_level=True)
class PySft(m.Sft):
pass
def test_release_and_shared_from_this():
# Exercises the most direct path from building a shared_from_this-visible
# shared_ptr to calling shared_from_this.
obj = PySft("PySft")
assert obj.history == "PySft"
assert m.use_count(obj) == 1
assert m.pass_shared_ptr(obj) == 2
assert obj.history == "PySft_PassSharedPtr"
assert m.use_count(obj) == 1
assert m.pass_shared_ptr(obj) == 2
assert obj.history == "PySft_PassSharedPtr_PassSharedPtr"
assert m.use_count(obj) == 1
def test_release_and_shared_from_this_leak():
obj = PySft("")
while True:
m.pass_shared_ptr(obj)
assert not obj.history
assert m.use_count(obj) == 1
break # Comment out for manual leak checking (use `top` command).
def test_release_and_stash():
# Exercises correct functioning of guarded_delete weak_ptr.
obj = PySft("PySft")
stash1 = m.SftSharedPtrStash(1)
stash1.Add(obj)
exp_hist = "PySft_Stash1Add"
assert obj.history == exp_hist
assert m.use_count(obj) == 2
assert stash1.history(0) == exp_hist
assert stash1.use_count(0) == 1
assert m.pass_shared_ptr(obj) == 3
exp_hist += "_PassSharedPtr"
assert obj.history == exp_hist
assert m.use_count(obj) == 2
assert stash1.history(0) == exp_hist
assert stash1.use_count(0) == 1
stash2 = m.SftSharedPtrStash(2)
stash2.Add(obj)
exp_hist += "_Stash2Add"
assert obj.history == exp_hist
assert m.use_count(obj) == 3
assert stash2.history(0) == exp_hist
assert stash2.use_count(0) == 2
stash2.Add(obj)
exp_hist += "_Stash2Add"
assert obj.history == exp_hist
assert m.use_count(obj) == 4
assert stash1.history(0) == exp_hist
assert stash1.use_count(0) == 3
assert stash2.history(0) == exp_hist
assert stash2.use_count(0) == 3
assert stash2.history(1) == exp_hist
assert stash2.use_count(1) == 3
del obj
assert stash2.history(0) == exp_hist
assert stash2.use_count(0) == 3
assert stash2.history(1) == exp_hist
assert stash2.use_count(1) == 3
stash2.Clear()
assert stash1.history(0) == exp_hist
assert stash1.use_count(0) == 1
def test_release_and_stash_leak():
obj = PySft("")
while True:
stash1 = m.SftSharedPtrStash(1)
stash1.Add(obj)
assert not obj.history
assert m.use_count(obj) == 2
assert stash1.use_count(0) == 1
stash1.Add(obj)
assert not obj.history
assert m.use_count(obj) == 3
assert stash1.use_count(0) == 2
assert stash1.use_count(1) == 2
break # Comment out for manual leak checking (use `top` command).
def test_release_and_stash_via_shared_from_this():
# Exercises that the smart_holder vptr is invisible to the shared_from_this mechanism.
obj = PySft("PySft")
stash1 = m.SftSharedPtrStash(1)
with pytest.raises(RuntimeError) as exc_info:
stash1.AddSharedFromThis(obj)
assert str(exc_info.value) == "bad_weak_ptr"
stash1.Add(obj)
assert obj.history == "PySft_Stash1Add"
assert stash1.use_count(0) == 1
stash1.AddSharedFromThis(obj)
assert obj.history == "PySft_Stash1Add_Stash1AddSharedFromThis"
assert stash1.use_count(0) == 2
assert stash1.use_count(1) == 2
def test_release_and_stash_via_shared_from_this_leak():
obj = PySft("")
while True:
stash1 = m.SftSharedPtrStash(1)
with pytest.raises(RuntimeError) as exc_info:
stash1.AddSharedFromThis(obj)
assert str(exc_info.value) == "bad_weak_ptr"
stash1.Add(obj)
assert not obj.history
assert stash1.use_count(0) == 1
stash1.AddSharedFromThis(obj)
assert not obj.history
assert stash1.use_count(0) == 2
assert stash1.use_count(1) == 2
break # Comment out for manual leak checking (use `top` command).
def test_pass_released_shared_ptr_as_unique_ptr():
# Exercises that returning a unique_ptr fails while a shared_from_this
# visible shared_ptr exists.
obj = PySft("PySft")
stash1 = m.SftSharedPtrStash(1)
stash1.Add(obj) # Releases shared_ptr to C++.
with pytest.raises(ValueError) as exc_info:
m.pass_unique_ptr(obj)
assert str(exc_info.value) == (
"Python instance is currently owned by a std::shared_ptr."
)
@pytest.mark.parametrize(
"make_f",
[
m.make_pure_cpp_sft_raw_ptr,
m.make_pure_cpp_sft_unq_ptr,
m.make_pure_cpp_sft_shd_ptr,
],
)
def test_pure_cpp_sft_raw_ptr(make_f):
# Exercises void_cast_raw_ptr logic for different situations.
obj = make_f("PureCppSft")
assert m.pass_shared_ptr(obj) == 3
assert obj.history == "PureCppSft_PassSharedPtr"
obj = make_f("PureCppSft")
stash1 = m.SftSharedPtrStash(1)
stash1.AddSharedFromThis(obj)
assert obj.history == "PureCppSft_Stash1AddSharedFromThis"
def test_multiple_registered_instances_for_same_pointee():
obj0 = PySft("PySft")
obj0.attachment_in_dict = "Obj0"
assert m.pass_through_shd_ptr(obj0) is obj0
while True:
obj = m.Sft(obj0)
assert obj is not obj0
obj_pt = m.pass_through_shd_ptr(obj)
# Unpredictable! Because registered_instances is as std::unordered_multimap.
assert obj_pt is obj0 or obj_pt is obj
# Multiple registered_instances for the same pointee can lead to unpredictable results:
if obj_pt is obj0:
assert obj_pt.attachment_in_dict == "Obj0"
else:
assert not hasattr(obj_pt, "attachment_in_dict")
assert obj0.history == "PySft"
break # Comment out for manual leak checking (use `top` command).
def test_multiple_registered_instances_for_same_pointee_leak():
obj0 = PySft("")
while True:
stash1 = m.SftSharedPtrStash(1)
stash1.Add(m.Sft(obj0))
assert stash1.use_count(0) == 1
stash1.Add(m.Sft(obj0))
assert stash1.use_count(0) == 1
assert stash1.use_count(1) == 1
assert not obj0.history
break # Comment out for manual leak checking (use `top` command).
def test_multiple_registered_instances_for_same_pointee_recursive():
while True:
obj0 = PySft("PySft")
if not env.PYPY:
obj0_wr = weakref.ref(obj0)
obj = obj0
# This loop creates a chain of instances linked by shared_ptrs.
for _ in range(10):
obj_next = m.Sft(obj)
assert obj_next is not obj
obj = obj_next
del obj_next
assert obj.history == "PySft"
del obj0
if not env.PYPY:
assert obj0_wr() is not None
del obj # This releases the chain recursively.
if not env.PYPY:
assert obj0_wr() is None
break # Comment out for manual leak checking (use `top` command).
# As of 2021-07-10 the pybind11 GitHub Actions valgrind build uses Python 3.9.
WORKAROUND_ENABLING_ROLLBACK_OF_PR3068 = env.LINUX and sys.version_info == (3, 9)
def test_std_make_shared_factory():
class PySftMakeShared(m.Sft):
def __init__(self, history):
super().__init__(history, 0)
obj = PySftMakeShared("PySftMakeShared")
assert obj.history == "PySftMakeShared"
if WORKAROUND_ENABLING_ROLLBACK_OF_PR3068:
try:
m.pass_through_shd_ptr(obj)
except RuntimeError as e:
str_exc_info_value = str(e)
else:
str_exc_info_value = "RuntimeError NOT RAISED"
else:
with pytest.raises(RuntimeError) as exc_info:
m.pass_through_shd_ptr(obj)
str_exc_info_value = str(exc_info.value)
assert (
str_exc_info_value
== "smart_holder_type_casters load_as_shared_ptr failure: not implemented:"
" trampoline-self-life-support for external shared_ptr to type inheriting"
" from std::enable_shared_from_this."
)