Issue #28544: Implement asyncio.Task in C.
This implementation provides additional 10-20% speed boost for
asyncio programs.
The patch also fixes _asynciomodule.c to use Arguments Clinic, and
makes '_schedule_callbacks' an overridable method (as it was in 3.5).
diff --git a/Lib/asyncio/base_tasks.py b/Lib/asyncio/base_tasks.py
new file mode 100644
index 0000000..5f34434
--- /dev/null
+++ b/Lib/asyncio/base_tasks.py
@@ -0,0 +1,76 @@
+import linecache
+import traceback
+
+from . import base_futures
+from . import coroutines
+
+
+def _task_repr_info(task):
+ info = base_futures._future_repr_info(task)
+
+ if task._must_cancel:
+ # replace status
+ info[0] = 'cancelling'
+
+ coro = coroutines._format_coroutine(task._coro)
+ info.insert(1, 'coro=<%s>' % coro)
+
+ if task._fut_waiter is not None:
+ info.insert(2, 'wait_for=%r' % task._fut_waiter)
+ return info
+
+
+def _task_get_stack(task, limit):
+ frames = []
+ try:
+ # 'async def' coroutines
+ f = task._coro.cr_frame
+ except AttributeError:
+ f = task._coro.gi_frame
+ if f is not None:
+ while f is not None:
+ if limit is not None:
+ if limit <= 0:
+ break
+ limit -= 1
+ frames.append(f)
+ f = f.f_back
+ frames.reverse()
+ elif task._exception is not None:
+ tb = task._exception.__traceback__
+ while tb is not None:
+ if limit is not None:
+ if limit <= 0:
+ break
+ limit -= 1
+ frames.append(tb.tb_frame)
+ tb = tb.tb_next
+ return frames
+
+
+def _task_print_stack(task, limit, file):
+ extracted_list = []
+ checked = set()
+ for f in task.get_stack(limit=limit):
+ lineno = f.f_lineno
+ co = f.f_code
+ filename = co.co_filename
+ name = co.co_name
+ if filename not in checked:
+ checked.add(filename)
+ linecache.checkcache(filename)
+ line = linecache.getline(filename, lineno, f.f_globals)
+ extracted_list.append((filename, lineno, name, line))
+ exc = task._exception
+ if not extracted_list:
+ print('No stack for %r' % task, file=file)
+ elif exc is not None:
+ print('Traceback for %r (most recent call last):' % task,
+ file=file)
+ else:
+ print('Stack for %r (most recent call last):' % task,
+ file=file)
+ traceback.print_list(extracted_list, file=file)
+ if exc is not None:
+ for line in traceback.format_exception_only(exc.__class__, exc):
+ print(line, file=file, end='')