moving to scripts

asq-env/lib/python3.9/site-packages/trio/_subprocess_platform/__init__.py

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+# Platform-specific subprocess bits'n'pieces.
+
+import os
+import sys
+from typing import Optional, Tuple, TYPE_CHECKING
+
+from .. import _core, _subprocess
+from .._abc import SendStream, ReceiveStream
+
+
+_wait_child_exiting_error: Optional[ImportError] = None
+_create_child_pipe_error: Optional[ImportError] = None
+
+
+# Fallback versions of the functions provided -- implementations
+# per OS are imported atop these at the bottom of the module.
+async def wait_child_exiting(process: "_subprocess.Process") -> None:
+    """Block until the child process managed by ``process`` is exiting.
+
+    It is invalid to call this function if the process has already
+    been waited on; that is, ``process.returncode`` must be None.
+
+    When this function returns, it indicates that a call to
+    :meth:`subprocess.Popen.wait` will immediately be able to
+    return the process's exit status. The actual exit status is not
+    consumed by this call, since :class:`~subprocess.Popen` wants
+    to be able to do that itself.
+    """
+    raise NotImplementedError from _wait_child_exiting_error  # pragma: no cover
+
+
+def create_pipe_to_child_stdin() -> Tuple[SendStream, int]:
+    """Create a new pipe suitable for sending data from this
+    process to the standard input of a child we're about to spawn.
+
+    Returns:
+      A pair ``(trio_end, subprocess_end)`` where ``trio_end`` is a
+      :class:`~trio.abc.SendStream` and ``subprocess_end`` is
+      something suitable for passing as the ``stdin`` argument of
+      :class:`subprocess.Popen`.
+    """
+    raise NotImplementedError from _create_child_pipe_error  # pragma: no cover
+
+
+def create_pipe_from_child_output() -> Tuple[ReceiveStream, int]:
+    """Create a new pipe suitable for receiving data into this
+    process from the standard output or error stream of a child
+    we're about to spawn.
+
+    Returns:
+      A pair ``(trio_end, subprocess_end)`` where ``trio_end`` is a
+      :class:`~trio.abc.ReceiveStream` and ``subprocess_end`` is
+      something suitable for passing as the ``stdin`` argument of
+      :class:`subprocess.Popen`.
+    """
+    raise NotImplementedError from _create_child_pipe_error  # pragma: no cover
+
+
+try:
+    if sys.platform == "win32":
+        from .windows import wait_child_exiting  # noqa: F811
+    elif sys.platform != "linux" and (TYPE_CHECKING or hasattr(_core, "wait_kevent")):
+        from .kqueue import wait_child_exiting  # noqa: F811
+    else:
+        from .waitid import wait_child_exiting  # noqa: F811
+except ImportError as ex:  # pragma: no cover
+    _wait_child_exiting_error = ex
+
+try:
+    if TYPE_CHECKING:
+        # Not worth type checking these definitions
+        pass
+
+    elif os.name == "posix":
+        from ..lowlevel import FdStream
+
+        def create_pipe_to_child_stdin():  # noqa: F811
+            rfd, wfd = os.pipe()
+            return FdStream(wfd), rfd
+
+        def create_pipe_from_child_output():  # noqa: F811
+            rfd, wfd = os.pipe()
+            return FdStream(rfd), wfd
+
+    elif os.name == "nt":
+        from .._windows_pipes import PipeSendStream, PipeReceiveStream
+
+        # This isn't exported or documented, but it's also not
+        # underscore-prefixed, and seems kosher to use. The asyncio docs
+        # for 3.5 included an example that imported socketpair from
+        # windows_utils (before socket.socketpair existed on Windows), and
+        # when asyncio.windows_utils.socketpair was removed in 3.7, the
+        # removal was mentioned in the release notes.
+        from asyncio.windows_utils import pipe as windows_pipe
+        import msvcrt
+
+        def create_pipe_to_child_stdin():  # noqa: F811
+            # for stdin, we want the write end (our end) to use overlapped I/O
+            rh, wh = windows_pipe(overlapped=(False, True))
+            return PipeSendStream(wh), msvcrt.open_osfhandle(rh, os.O_RDONLY)
+
+        def create_pipe_from_child_output():  # noqa: F811
+            # for stdout/err, it's the read end that's overlapped
+            rh, wh = windows_pipe(overlapped=(True, False))
+            return PipeReceiveStream(rh), msvcrt.open_osfhandle(wh, 0)
+
+    else:  # pragma: no cover
+        raise ImportError("pipes not implemented on this platform")
+
+except ImportError as ex:  # pragma: no cover
+    _create_child_pipe_error = ex

asq-env/lib/python3.9/site-packages/trio/_subprocess_platform/kqueue.py

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+import sys
+import select
+from typing import TYPE_CHECKING
+from .. import _core, _subprocess
+
+assert (sys.platform != "win32" and sys.platform != "linux") or not TYPE_CHECKING
+
+
+async def wait_child_exiting(process: "_subprocess.Process") -> None:
+    kqueue = _core.current_kqueue()
+    try:
+        from select import KQ_NOTE_EXIT
+    except ImportError:  # pragma: no cover
+        # pypy doesn't define KQ_NOTE_EXIT:
+        # https://bitbucket.org/pypy/pypy/issues/2921/
+        # I verified this value against both Darwin and FreeBSD
+        KQ_NOTE_EXIT = 0x80000000
+
+    make_event = lambda flags: select.kevent(
+        process.pid, filter=select.KQ_FILTER_PROC, flags=flags, fflags=KQ_NOTE_EXIT
+    )
+
+    try:
+        kqueue.control([make_event(select.KQ_EV_ADD | select.KQ_EV_ONESHOT)], 0)
+    except ProcessLookupError:  # pragma: no cover
+        # This can supposedly happen if the process is in the process
+        # of exiting, and it can even be the case that kqueue says the
+        # process doesn't exist before waitpid(WNOHANG) says it hasn't
+        # exited yet. See the discussion in https://chromium.googlesource.com/
+        # chromium/src/base/+/master/process/kill_mac.cc .
+        # We haven't actually seen this error occur since we added
+        # locking to prevent multiple calls to wait_child_exiting()
+        # for the same process simultaneously, but given the explanation
+        # in Chromium it seems we should still keep the check.
+        return
+
+    def abort(_):
+        kqueue.control([make_event(select.KQ_EV_DELETE)], 0)
+        return _core.Abort.SUCCEEDED
+
+    await _core.wait_kevent(process.pid, select.KQ_FILTER_PROC, abort)

asq-env/lib/python3.9/site-packages/trio/_subprocess_platform/waitid.py

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+import errno
+import math
+import os
+import sys
+
+from .. import _core, _subprocess
+from .._sync import CapacityLimiter, Event
+from .._threads import to_thread_run_sync
+
+try:
+    from os import waitid
+
+    def sync_wait_reapable(pid):
+        waitid(os.P_PID, pid, os.WEXITED | os.WNOWAIT)
+
+
+except ImportError:
+    # pypy doesn't define os.waitid so we need to pull it out ourselves
+    # using cffi: https://bitbucket.org/pypy/pypy/issues/2922/
+    import cffi
+
+    waitid_ffi = cffi.FFI()
+
+    # Believe it or not, siginfo_t starts with fields in the
+    # same layout on both Linux and Darwin. The Linux structure
+    # is bigger so that's what we use to size `pad`; while
+    # there are a few extra fields in there, most of it is
+    # true padding which would not be written by the syscall.
+    waitid_ffi.cdef(
+        """
+typedef struct siginfo_s {
+    int si_signo;
+    int si_errno;
+    int si_code;
+    int si_pid;
+    int si_uid;
+    int si_status;
+    int pad[26];
+} siginfo_t;
+int waitid(int idtype, int id, siginfo_t* result, int options);
+"""
+    )
+    waitid = waitid_ffi.dlopen(None).waitid
+
+    def sync_wait_reapable(pid):
+        P_PID = 1
+        WEXITED = 0x00000004
+        if sys.platform == "darwin":  # pragma: no cover
+            # waitid() is not exposed on Python on Darwin but does
+            # work through CFFI; note that we typically won't get
+            # here since Darwin also defines kqueue
+            WNOWAIT = 0x00000020
+        else:
+            WNOWAIT = 0x01000000
+        result = waitid_ffi.new("siginfo_t *")
+        while waitid(P_PID, pid, result, WEXITED | WNOWAIT) < 0:
+            got_errno = waitid_ffi.errno
+            if got_errno == errno.EINTR:
+                continue
+            raise OSError(got_errno, os.strerror(got_errno))
+
+
+# adapted from
+# https://github.com/python-trio/trio/issues/4#issuecomment-398967572
+
+waitid_limiter = CapacityLimiter(math.inf)
+
+
+async def _waitid_system_task(pid: int, event: Event) -> None:
+    """Spawn a thread that waits for ``pid`` to exit, then wake any tasks
+    that were waiting on it.
+    """
+    # cancellable=True: if this task is cancelled, then we abandon the
+    # thread to keep running waitpid in the background. Since this is
+    # always run as a system task, this will only happen if the whole
+    # call to trio.run is shutting down.
+
+    try:
+        await to_thread_run_sync(
+            sync_wait_reapable, pid, cancellable=True, limiter=waitid_limiter
+        )
+    except OSError:
+        # If waitid fails, waitpid will fail too, so it still makes
+        # sense to wake up the callers of wait_process_exiting(). The
+        # most likely reason for this error in practice is a child
+        # exiting when wait() is not possible because SIGCHLD is
+        # ignored.
+        pass
+    finally:
+        event.set()
+
+
+async def wait_child_exiting(process: "_subprocess.Process") -> None:
+    # Logic of this function:
+    # - The first time we get called, we create an Event and start
+    #   an instance of _waitid_system_task that will set the Event
+    #   when waitid() completes. If that Event is set before
+    #   we get cancelled, we're good.
+    # - Otherwise, a following call after the cancellation must
+    #   reuse the Event created during the first call, lest we
+    #   create an arbitrary number of threads waiting on the same
+    #   process.
+
+    if process._wait_for_exit_data is None:
+        process._wait_for_exit_data = event = Event()  # type: ignore
+        _core.spawn_system_task(_waitid_system_task, process.pid, event)
+    assert isinstance(process._wait_for_exit_data, Event)
+    await process._wait_for_exit_data.wait()

asq-env/lib/python3.9/site-packages/trio/_subprocess_platform/windows.py

@@ -0,0 +1,6 @@
+from .. import _subprocess
+from .._wait_for_object import WaitForSingleObject
+
+
+async def wait_child_exiting(process: "_subprocess.Process") -> None:
+    await WaitForSingleObject(int(process._proc._handle))