xref: /aosp_15_r20/prebuilts/build-tools/common/py3-stdlib/asyncio/coroutines.py (revision cda5da8d549138a6648c5ee6d7a49cf8f4a657be)
1__all__ = 'iscoroutinefunction', 'iscoroutine'
2
3import collections.abc
4import inspect
5import os
6import sys
7import traceback
8import types
9
10
11def _is_debug_mode():
12    # See: https://docs.python.org/3/library/asyncio-dev.html#asyncio-debug-mode.
13    return sys.flags.dev_mode or (not sys.flags.ignore_environment and
14                                  bool(os.environ.get('PYTHONASYNCIODEBUG')))
15
16
17# A marker for iscoroutinefunction.
18_is_coroutine = object()
19
20
21def iscoroutinefunction(func):
22    """Return True if func is a decorated coroutine function."""
23    return (inspect.iscoroutinefunction(func) or
24            getattr(func, '_is_coroutine', None) is _is_coroutine)
25
26
27# Prioritize native coroutine check to speed-up
28# asyncio.iscoroutine.
29_COROUTINE_TYPES = (types.CoroutineType, types.GeneratorType,
30                    collections.abc.Coroutine)
31_iscoroutine_typecache = set()
32
33
34def iscoroutine(obj):
35    """Return True if obj is a coroutine object."""
36    if type(obj) in _iscoroutine_typecache:
37        return True
38
39    if isinstance(obj, _COROUTINE_TYPES):
40        # Just in case we don't want to cache more than 100
41        # positive types.  That shouldn't ever happen, unless
42        # someone stressing the system on purpose.
43        if len(_iscoroutine_typecache) < 100:
44            _iscoroutine_typecache.add(type(obj))
45        return True
46    else:
47        return False
48
49
50def _format_coroutine(coro):
51    assert iscoroutine(coro)
52
53    def get_name(coro):
54        # Coroutines compiled with Cython sometimes don't have
55        # proper __qualname__ or __name__.  While that is a bug
56        # in Cython, asyncio shouldn't crash with an AttributeError
57        # in its __repr__ functions.
58        if hasattr(coro, '__qualname__') and coro.__qualname__:
59            coro_name = coro.__qualname__
60        elif hasattr(coro, '__name__') and coro.__name__:
61            coro_name = coro.__name__
62        else:
63            # Stop masking Cython bugs, expose them in a friendly way.
64            coro_name = f'<{type(coro).__name__} without __name__>'
65        return f'{coro_name}()'
66
67    def is_running(coro):
68        try:
69            return coro.cr_running
70        except AttributeError:
71            try:
72                return coro.gi_running
73            except AttributeError:
74                return False
75
76    coro_code = None
77    if hasattr(coro, 'cr_code') and coro.cr_code:
78        coro_code = coro.cr_code
79    elif hasattr(coro, 'gi_code') and coro.gi_code:
80        coro_code = coro.gi_code
81
82    coro_name = get_name(coro)
83
84    if not coro_code:
85        # Built-in types might not have __qualname__ or __name__.
86        if is_running(coro):
87            return f'{coro_name} running'
88        else:
89            return coro_name
90
91    coro_frame = None
92    if hasattr(coro, 'gi_frame') and coro.gi_frame:
93        coro_frame = coro.gi_frame
94    elif hasattr(coro, 'cr_frame') and coro.cr_frame:
95        coro_frame = coro.cr_frame
96
97    # If Cython's coroutine has a fake code object without proper
98    # co_filename -- expose that.
99    filename = coro_code.co_filename or '<empty co_filename>'
100
101    lineno = 0
102
103    if coro_frame is not None:
104        lineno = coro_frame.f_lineno
105        coro_repr = f'{coro_name} running at {filename}:{lineno}'
106
107    else:
108        lineno = coro_code.co_firstlineno
109        coro_repr = f'{coro_name} done, defined at {filename}:{lineno}'
110
111    return coro_repr
112