_emerge.EbuildIpcDaemon module

class _emerge.EbuildIpcDaemon.EbuildIpcDaemon(**kwargs)

Bases: _emerge.FifoIpcDaemon.FifoIpcDaemon

This class serves as an IPC daemon, which ebuild processes can use to communicate with portage’s main python process.

Here are a few possible uses:

  1. Robust subshell/subprocess die support. This allows the ebuild environment to reliably die without having to rely on signal IPC.

  2. Delegation of portageq calls to the main python process, eliminating performance and userpriv permission issues.

  3. Reliable ebuild termination in cases when the ebuild has accidentally left orphan processes running in the background (as in bug #278895).

  4. Detect cases in which bash has exited unexpectedly (as in bug #190128).

_async_wait()

Subclasses call this method in order to invoke exit listeners when self.returncode is set. Subclasses may override this method in order to perform cleanup. The default implementation for this method simply calls self.wait(), which will immediately raise an InvalidStateError if the event loop is running and self.returncode is None.

_bufsize = 4096
_cancel()

Subclasses should implement this, as a template method to be called by AsynchronousTask.cancel().

_cancelled_returncode = -2
_exit_listener_cb(listener)
_exit_listener_handles
_exit_listeners
_file_names = ('pipe_in',)
_files
_files_dict

alias of portage.cache.mappings.slot_dict_class.<locals>.SlotDict

_input_handler()
_poll()
_read_array(f)

NOTE: array.fromfile() is used here only for testing purposes, because it has bugs in all known versions of Python (including Python 2.7 and Python 3.2). See PipeReaderArrayTestCase.

A benchmark that copies bytes from /dev/zero to /dev/null shows that arrays give a 15% performance improvement for Python 2.7.14. However, arrays significantly decrease performance for Python 3.

_read_buf(fd)

Read self._bufsize into a string of bytes, handling EAGAIN and EIO. This will only call os.read() once, so the caller should call this method in a loop until either None or an empty string of bytes is returned. An empty string of bytes indicates EOF. None indicates EAGAIN.

NOTE: os.read() will be called regardless of the event flags,

since otherwise data may be lost (see bug #531724).

Parameters

fd (int) – file descriptor (non-blocking mode required)

Return type

bytes or None

Returns

A string of bytes, or None

_registered
_reopen_input()

Re-open the input stream, in order to suppress POLLHUP events (bug #339976).

_send_reply(reply)
_start()
_start_hook()
_start_listeners
_unregister()

Unregister from the scheduler and close open files.

_wait_hook()

Call this method after the task completes, just before returning the returncode from wait() or poll(). This hook is used to trigger exit listeners when the returncode first becomes available.

_wait_loop(timeout=None)
_was_cancelled()

If cancelled, set returncode if necessary and return True. Otherwise, return False.

addExitListener(f)

The function will be called with one argument, a reference to self.

addStartListener(f)

The function will be called with one argument, a reference to self.

async_wait()

Wait for returncode asynchronously. Notification is available via the add_done_callback method of the returned Future instance.

Returns

Future, result is self.returncode

background
cancel()

Cancel the task, but do not wait for exit status. If asynchronous exit notification is desired, then use addExitListener to add a listener before calling this method. NOTE: Synchronous waiting for status is not supported, since it would be vulnerable to hitting the recursion limit when a large number of tasks need to be terminated simultaneously, like in bug #402335.

cancelled
commands
copy()

Create a new instance and copy all attributes defined from __slots__ (including those from inherited classes).

input_fifo
isAlive()
output_fifo
poll()
removeExitListener(f)
removeStartListener(f)
returncode
scheduler
start()

Start an asynchronous task and then return as soon as possible.

wait()

Wait for the returncode attribute to become ready, and return it. If the returncode is not ready and the event loop is already running, then the async_wait() method should be used instead of wait(), because wait() will raise asyncio.InvalidStateError in this case.

Return type

int

Returns

the value of self.returncode