From 9f614f370eae3b36b822803cb308d774785ba962 Mon Sep 17 00:00:00 2001
From: Johannes Maron <johannes@maron.family>
Date: Tue, 30 Jun 2026 22:42:23 +0200
Subject: [PATCH] Resolve #19 -- Backport Pickel support from Django 6.1

---
 .github/workflows/ci.yml    |  1 +
 pyproject.toml              |  3 ++-
 tests/test_executor.py      | 35 +++++++++++++++--------------------
 threadmill/backends/base.py | 23 +++++++++++++++++++++++
 4 files changed, 41 insertions(+), 21 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e0fd6ae..c5caa81 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -26,6 +26,7 @@ jobs:
           - "3.13"
           - "3.14"
         django-version:
+          - "6.0.0"
           - "6.1a1"
     runs-on: ${{ matrix.os }}
     services:
diff --git a/pyproject.toml b/pyproject.toml
index b1c93f9..fee79cb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -30,10 +30,11 @@ classifiers = [
   "Programming Language :: Python :: 3.13",
   "Programming Language :: Python :: 3.14",
   "Framework :: Django",
+  "Framework :: Django :: 6.0",
   "Framework :: Django :: 6.1",
 ]
 requires-python = ">=3.12"
-dependencies = ["django>=6.1a1"]
+dependencies = ["django>=6.0"]
 
 [project.optional-dependencies]
 redis = ["redis>=5.0"]
diff --git a/tests/test_executor.py b/tests/test_executor.py
index 520d060..19e1c09 100644
--- a/tests/test_executor.py
+++ b/tests/test_executor.py
@@ -7,7 +7,13 @@
 import time
 import uuid
 
-from django.tasks import Task, TaskResult, TaskResultStatus, default_task_backend
+from django.tasks import (
+    TaskContext,
+    TaskResult,
+    TaskResultStatus,
+    default_task_backend,
+    task,
+)
 from django.utils import timezone
 
 from tests.testapp.tasks import boom, echo
@@ -15,29 +21,21 @@
 from threadmill.executor import TaskExecutor, WorkerProcess, WorkerThread  # noqa: E402
 
 
+@task(queue_name="default")
 def _add(x, y):
     return x + y
 
 
-ADD_TASK = Task(func=_add, queue_name="default")
-
-
+@task(queue_name="default", takes_context=True)
 def _context_captor(context):
-    """Task function that captures the context it receives."""
-    _context_captor.captured = context
-    return 42
-
-
-CONTEXT_TASK = Task(func=_context_captor, queue_name="default", takes_context=True)
+    return context
 
 
+@task(queue_name="default")
 async def _async_task():
     return 99
 
 
-ASYNC_TASK = Task(func=_async_task, queue_name="default")
-
-
 def _task_result(task, *args, **kwargs) -> TaskResult:
     """Build a READY `TaskResult` without touching Redis."""
     return TaskResult(
@@ -290,20 +288,17 @@ def test_execute_task_result__preserves_worker_ids(self):
 
     def test_call_task__calls_function_with_args(self):
         """call_task invokes the task function with args and kwargs."""
-        result = WorkerThread.call_task(_task_result(ADD_TASK, 1, y=2))
+        result = WorkerThread.call_task(_task_result(_add, 1, y=2))
         assert result == 3
 
     def test_call_task__passes_context_when_takes_context(self):
         """call_task passes TaskContext when task.takes_context is True."""
-        _context_captor.captured = None
-        result = WorkerThread.call_task(_task_result(CONTEXT_TASK))
-        assert result == 42
-        assert _context_captor.captured is not None
-        assert _context_captor.captured.task_result.task is CONTEXT_TASK
+        result = WorkerThread.call_task(_task_result(_context_captor))
+        assert isinstance(result, TaskContext)
 
     def test_call_task__runs_async_function(self):
         """call_task runs async task functions with asyncio.run."""
-        result = WorkerThread.call_task(_task_result(ASYNC_TASK))
+        result = WorkerThread.call_task(_task_result(_async_task))
         assert result == 99
 
     def test_create_task_error__builds_task_error(self):
diff --git a/threadmill/backends/base.py b/threadmill/backends/base.py
index ceb6537..14e9195 100644
--- a/threadmill/backends/base.py
+++ b/threadmill/backends/base.py
@@ -7,12 +7,34 @@
 import threading
 from abc import ABC
 
+import django
 from django.core.serializers.json import DjangoJSONEncoder
 from django.tasks import DEFAULT_TASK_QUEUE_NAME, Task, TaskResult, TaskResultStatus
 from django.tasks.backends.base import BaseTaskBackend
 from django.tasks.base import TaskError
 from django.utils.module_loading import import_string
 
+if django.VERSION == (6, 0):
+    # https://github.com/django/django/commit/8c8b833d32c02d3ae6f43b04bb1e45968796b402
+    @dataclasses.dataclass(frozen=True, slots=True, kw_only=True)
+    class Task(Task):
+        @classmethod
+        def _reconstruct(cls, kwargs):
+            func_path = kwargs["func"]
+            try:
+                func = import_string(func_path)
+                kwargs["func"] = func.func
+            except (ImportError, AttributeError) as e:
+                msg = f"Expected {func_path!r} to point to a Task instance."
+                raise ValueError(msg) from e
+            return cls(**kwargs)
+
+        def __reduce__(self):
+            kwargs = {f.name: getattr(self, f.name) for f in dataclasses.fields(self)}
+            kwargs["func"] = self.module_path
+
+            return (self.__class__._reconstruct, (kwargs,))
+
 
 @dataclasses.dataclass(kw_only=True, slots=True)
 class QueueCounts:
@@ -106,6 +128,7 @@ def default(self, o):
 class ThreadmillTaskBackend(BaseTaskBackend, ABC):
     """Interface for task queues to be processed by the executor."""
 
+    task_class = Task  # can be removed in the future when Django 6.0 support is dropped
     supports_async_task = True
     supports_get_result = True
     broker_class: type[Broker] | None = None