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fix: Handle thread/process affinity when freeing objects #285

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Merged
tmathern merged 8 commits into from
Jun 15, 2026
Merged

fix: Handle thread/process affinity when freeing objects #285

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674e667
fix: Defend threads
tmathern Jun 11, 2026
915e6f1
fix: Update comments
tmathern Jun 11, 2026
eda40a1
fix: Guard
tmathern Jun 11, 2026
61c194c
fix: Defen threads
tmathern Jun 11, 2026
70843dd
fix: Debug cleanup
tmathern Jun 12, 2026
f75c74c
ci: Merge in main
tmathern Jun 12, 2026
c6db994
fix: Update baseline and add baseline for new scenario
tmathern Jun 12, 2026
944b712
Bump version to 0.35.0
tmathern Jun 15, 2026
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2 changes: 1 addition & 1 deletion pyproject.toml
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Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"

[project]
name = "c2pa-python"
version = "0.34.0"
version = "0.35.0"
requires-python = ">=3.10"
description = "Python bindings for the C2PA Content Authenticity Initiative (CAI) library"
readme = { file = "README.md", content-type = "text/markdown" }
Expand Down
12 changes: 11 additions & 1 deletion src/c2pa/c2pa.py
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Original file line number Diff line number Diff line change
Expand Up @@ -22,7 +22,7 @@
from pathlib import Path
from typing import Optional, Union, Callable, Any, overload
import io
from .lib import dynamically_load_library
from .lib import dynamically_load_library, record_owner_pid, is_foreign_process
import mimetypes
from itertools import count

Expand Down Expand Up @@ -238,6 +238,7 @@ def __init__(self):
self._lifecycle_state = LifecycleState.UNINITIALIZED
self._handle = None
_clear_error_state()
record_owner_pid(self)

@staticmethod
def _free_native_ptr(ptr):
Expand Down Expand Up @@ -280,6 +281,8 @@ def _mark_consumed(self):
def _cleanup_resources(self):
"""Release native resources idempotently."""
try:
if is_foreign_process(self):
return
if (
hasattr(self, '_lifecycle_state')
and self._lifecycle_state != LifecycleState.CLOSED
Expand Down Expand Up @@ -1768,6 +1771,7 @@ def flush_callback(ctx):
raise Exception("Failed to create stream: {}".format(error))

self._initialized = True
record_owner_pid(self)

def __enter__(self):
"""Context manager entry."""
Expand All @@ -1786,6 +1790,8 @@ def __del__(self):
hasn't been explicitly closed.
"""
try:
if is_foreign_process(self):
return
# Only cleanup if not already closed and we have a valid stream
if hasattr(self, '_closed') and not self._closed:
stream = self._stream
Expand Down Expand Up @@ -1816,6 +1822,10 @@ def close(self):
"""
if self._closed:
return
if is_foreign_process(self):
self._closed = True
self._initialized = False
return

try:
# Clean up stream first as it depends on callbacks
Expand Down
25 changes: 25 additions & 0 deletions src/c2pa/lib.py
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Original file line number Diff line number Diff line change
Expand Up @@ -299,3 +299,28 @@ def dynamically_load_library(
raise RuntimeError(f"Could not find {c2pa_lib_name} in any of the search paths")

return c2pa_lib


def record_owner_pid(obj):
"""Keep the PID that created this native-handle wrapper
(call from __init__ as needed).
"""
obj._owner_pid = os.getpid()


def is_foreign_process(obj):
"""Return True when this object is being finalized in a forked child that did not
create it. After a multithreaded fork(), native mutexes may be held by threads
absent in the child -> any lock() call deadlocks. Callers must skip native frees
when this returns True.

Skipping the free does not cause a cumulative leak. If the child calls exec() the
address space is replaced entirely; if it exits, the OS reclaims all process memory.
Even a long-lived fork child (e.g. a multiprocessing fork-start worker) leaks at most
the objects inherited at fork time — a one-time, bounded amount reclaimed when the
child terminates. Objects the child creates itself carry the child's PID and are
freed normally.

Defensive default: if _owner_pid was never set, returns False (no regression)."""
owner = getattr(obj, '_owner_pid', None)
return owner is not None and owner != os.getpid()
213 changes: 124 additions & 89 deletions tests/perf/baseline.json
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Original file line number Diff line number Diff line change
Expand Up @@ -2,154 +2,189 @@
"_meta": {
"memray_version": "1.19.3",
"python_version": "3.12.13",
"c2pa_native_version": "c2pa-v0.86.1",
"iterations": 100,
"c2pa_native_version": "c2pa-v0.88.0",
"iterations": 250,
"perf_env": "python-3.12-slim",
"arch": "aarch64"
},
"reader_jpeg_legacy": {
"peak_bytes": 3730321,
"leaked_bytes": 3236992,
"total_allocations": 717596
"peak_bytes": 3762136,
"leaked_bytes": 3262031,
"total_allocations": 1660100
},
"reader_jpeg_with_context": {
"peak_bytes": 3724412,
"leaked_bytes": 3229219,
"total_allocations": 711543
"peak_bytes": 3756118,
"leaked_bytes": 3254069,
"total_allocations": 1646550
},
"reader_mp4": {
"peak_bytes": 4099225,
"leaked_bytes": 3228160,
"total_allocations": 2084373
"peak_bytes": 4208976,
"leaked_bytes": 3253426,
"total_allocations": 4963836
},
"reader_wav": {
"peak_bytes": 4399719,
"leaked_bytes": 3238102,
"total_allocations": 408059
"peak_bytes": 4431268,
"leaked_bytes": 3263354,
"total_allocations": 888612
},
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"total_allocations": 550105
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"total_allocations": 1235555
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}
}
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