Files
pytest-xdist/src/xdist/dsession.py
2024-04-06 21:54:44 +03:00

532 lines
20 KiB
Python

from __future__ import annotations
from enum import auto
from enum import Enum
from queue import Empty
from queue import Queue
import sys
from typing import Sequence
import pytest
from xdist.remote import Producer
from xdist.scheduler import EachScheduling
from xdist.scheduler import LoadFileScheduling
from xdist.scheduler import LoadGroupScheduling
from xdist.scheduler import LoadScheduling
from xdist.scheduler import LoadScopeScheduling
from xdist.scheduler import WorkStealingScheduling
from xdist.workermanage import NodeManager
class Interrupted(KeyboardInterrupt):
"""signals an immediate interruption."""
class DSession:
"""A pytest plugin which runs a distributed test session.
At the beginning of the test session this creates a NodeManager
instance which creates and starts all nodes. Nodes then emit
events processed in the pytest_runtestloop hook using the worker_*
methods.
Once a node is started it will automatically start running the
pytest mainloop with some custom hooks. This means a node
automatically starts collecting tests. Once tests are collected
it will wait for instructions.
"""
def __init__(self, config):
self.config = config
self.log = Producer("dsession", enabled=config.option.debug)
self.nodemanager = None
self.sched = None
self.shuttingdown = False
self.countfailures = 0
self.maxfail = config.getvalue("maxfail")
self.queue = Queue()
self._session = None
self._failed_collection_errors = {}
self._active_nodes = set()
self._failed_nodes_count = 0
self._max_worker_restart = get_default_max_worker_restart(self.config)
# summary message to print at the end of the session
self._summary_report = None
self.terminal = config.pluginmanager.getplugin("terminalreporter")
if self.terminal:
self.trdist = TerminalDistReporter(config)
config.pluginmanager.register(self.trdist, "terminaldistreporter")
@property
def session_finished(self):
"""Return True if the distributed session has finished.
This means all nodes have executed all test items. This is
used by pytest_runtestloop to break out of its loop.
"""
return bool(self.shuttingdown and not self._active_nodes)
def report_line(self, line):
if self.terminal and self.config.option.verbose >= 0:
self.terminal.write_line(line)
@pytest.hookimpl(trylast=True)
def pytest_sessionstart(self, session):
"""Creates and starts the nodes.
The nodes are setup to put their events onto self.queue. As
soon as nodes start they will emit the worker_workerready event.
"""
self.nodemanager = NodeManager(self.config)
nodes = self.nodemanager.setup_nodes(putevent=self.queue.put)
self._active_nodes.update(nodes)
self._session = session
@pytest.hookimpl
def pytest_sessionfinish(self, session):
"""Shutdown all nodes."""
nm = getattr(self, "nodemanager", None) # if not fully initialized
if nm is not None:
nm.teardown_nodes()
self._session = None
@pytest.hookimpl
def pytest_collection(self):
# prohibit collection of test items in controller process
return True
@pytest.hookimpl(trylast=True)
def pytest_xdist_make_scheduler(self, config, log):
dist = config.getvalue("dist")
schedulers = {
"each": EachScheduling,
"load": LoadScheduling,
"loadscope": LoadScopeScheduling,
"loadfile": LoadFileScheduling,
"loadgroup": LoadGroupScheduling,
"worksteal": WorkStealingScheduling,
}
return schedulers[dist](config, log)
@pytest.hookimpl
def pytest_runtestloop(self):
self.sched = self.config.hook.pytest_xdist_make_scheduler(
config=self.config, log=self.log
)
assert self.sched is not None
self.shouldstop = False
pending_exception = None
while not self.session_finished:
self.loop_once()
if self.shouldstop:
self.triggershutdown()
pending_exception = Interrupted(str(self.shouldstop))
if pending_exception:
raise pending_exception
return True
def loop_once(self):
"""Process one callback from one of the workers."""
while 1:
if not self._active_nodes:
# If everything has died stop looping
self.triggershutdown()
raise RuntimeError("Unexpectedly no active workers available")
try:
eventcall = self.queue.get(timeout=2.0)
break
except Empty:
continue
callname, kwargs = eventcall
assert callname, kwargs
method = "worker_" + callname
call = getattr(self, method)
self.log("calling method", method, kwargs)
call(**kwargs)
if self.sched.tests_finished:
self.triggershutdown()
#
# callbacks for processing events from workers
#
def worker_workerready(self, node, workerinfo):
"""Emitted when a node first starts up.
This adds the node to the scheduler, nodes continue with
collection without any further input.
"""
node.workerinfo = workerinfo
node.workerinfo["id"] = node.gateway.id
node.workerinfo["spec"] = node.gateway.spec
self.config.hook.pytest_testnodeready(node=node)
if self.shuttingdown:
node.shutdown()
else:
self.sched.add_node(node)
def worker_workerfinished(self, node):
"""Emitted when node executes its pytest_sessionfinish hook.
Removes the node from the scheduler.
The node might not be in the scheduler if it had not emitted
workerready before shutdown was triggered.
"""
self.config.hook.pytest_testnodedown(node=node, error=None)
if node.workeroutput["exitstatus"] == 2: # keyboard-interrupt
self.shouldstop = f"{node} received keyboard-interrupt"
self.worker_errordown(node, "keyboard-interrupt")
return
shouldfail = node.workeroutput["shouldfail"]
shouldstop = node.workeroutput["shouldstop"]
for shouldx in [shouldfail, shouldstop]:
if shouldx:
if not self.shouldstop:
self.shouldstop = shouldx
break
else:
if node in self.sched.nodes:
crashitem = self.sched.remove_node(node)
assert not crashitem, (crashitem, node)
self._active_nodes.remove(node)
def worker_internal_error(self, node, formatted_error):
"""
pytest_internalerror() was called on the worker.
pytest_internalerror() arguments are an excinfo and an excrepr, which can't
be serialized, so we go with a poor man's solution of raising an exception
here ourselves using the formatted message.
"""
self._active_nodes.remove(node)
try:
assert False, formatted_error
except AssertionError:
excinfo = pytest.ExceptionInfo.from_current()
excrepr = excinfo.getrepr()
self.config.hook.pytest_internalerror(excrepr=excrepr, excinfo=excinfo)
def worker_errordown(self, node, error):
"""Emitted by the WorkerController when a node dies."""
self.config.hook.pytest_testnodedown(node=node, error=error)
try:
crashitem = self.sched.remove_node(node)
except KeyError:
pass
else:
if crashitem:
self.handle_crashitem(crashitem, node)
self._failed_nodes_count += 1
maximum_reached = (
self._max_worker_restart is not None
and self._failed_nodes_count > self._max_worker_restart
)
if maximum_reached:
if self._max_worker_restart == 0:
msg = f"worker {node.gateway.id} crashed and worker restarting disabled"
else:
msg = "maximum crashed workers reached: %d" % self._max_worker_restart
self._summary_report = msg
self.report_line("\n" + msg)
self.triggershutdown()
else:
self.report_line("\nreplacing crashed worker %s" % node.gateway.id)
self.shuttingdown = False
self._clone_node(node)
self._active_nodes.remove(node)
@pytest.hookimpl
def pytest_terminal_summary(self, terminalreporter):
if self.config.option.verbose >= 0 and self._summary_report:
terminalreporter.write_sep("=", f"xdist: {self._summary_report}")
def worker_collectionfinish(self, node, ids):
"""Worker has finished test collection.
This adds the collection for this node to the scheduler. If
the scheduler indicates collection is finished (i.e. all
initial nodes have submitted their collections), then tells the
scheduler to schedule the collected items. When initiating
scheduling the first time it logs which scheduler is in use.
"""
if self.shuttingdown:
return
self.config.hook.pytest_xdist_node_collection_finished(node=node, ids=ids)
# tell session which items were effectively collected otherwise
# the controller node will finish the session with EXIT_NOTESTSCOLLECTED
self._session.testscollected = len(ids)
self.sched.add_node_collection(node, ids)
if self.terminal:
self.trdist.setstatus(
node.gateway.spec, WorkerStatus.CollectionDone, tests_collected=len(ids)
)
if self.sched.collection_is_completed:
if self.terminal and not self.sched.has_pending:
self.trdist.ensure_show_status()
self.terminal.write_line("")
if self.config.option.verbose > 0:
self.terminal.write_line(
f"scheduling tests via {self.sched.__class__.__name__}"
)
self.sched.schedule()
def worker_logstart(self, node, nodeid, location):
"""Emitted when a node calls the pytest_runtest_logstart hook."""
self.config.hook.pytest_runtest_logstart(nodeid=nodeid, location=location)
def worker_logfinish(self, node, nodeid, location):
"""Emitted when a node calls the pytest_runtest_logfinish hook."""
self.config.hook.pytest_runtest_logfinish(nodeid=nodeid, location=location)
def worker_testreport(self, node, rep):
"""Emitted when a node calls the pytest_runtest_logreport hook."""
rep.node = node
self.config.hook.pytest_runtest_logreport(report=rep)
self._handlefailures(rep)
def worker_runtest_protocol_complete(self, node, item_index, duration):
"""
Emitted when a node fires the 'runtest_protocol_complete' event,
signalling that a test has completed the runtestprotocol and should be
removed from the pending list in the scheduler.
"""
self.sched.mark_test_complete(node, item_index, duration)
def worker_unscheduled(self, node, indices):
"""
Emitted when a node fires the 'unscheduled' event, signalling that
some tests have been removed from the worker's queue and should be
sent to some worker again.
This should happen only in response to 'steal' command, so schedulers
not using 'steal' command don't have to implement it.
"""
self.sched.remove_pending_tests_from_node(node, indices)
def worker_collectreport(self, node, rep):
"""Emitted when a node calls the pytest_collectreport hook.
Because we only need the report when there's a failure/skip, as optimization
we only expect to receive failed/skipped reports from workers (#330).
"""
assert not rep.passed
self._failed_worker_collectreport(node, rep)
def worker_warning_captured(self, warning_message, when, item):
"""Emitted when a node calls the pytest_warning_captured hook (deprecated in 6.0)."""
# This hook as been removed in pytest 7.1, and we can remove support once we only
# support pytest >=7.1.
kwargs = dict(warning_message=warning_message, when=when, item=item)
self.config.hook.pytest_warning_captured.call_historic(kwargs=kwargs)
def worker_warning_recorded(self, warning_message, when, nodeid, location):
"""Emitted when a node calls the pytest_warning_recorded hook."""
kwargs = dict(
warning_message=warning_message, when=when, nodeid=nodeid, location=location
)
self.config.hook.pytest_warning_recorded.call_historic(kwargs=kwargs)
def _clone_node(self, node):
"""Return new node based on an existing one.
This is normally for when a node dies, this will copy the spec
of the existing node and create a new one with a new id. The
new node will have been setup so it will start calling the
"worker_*" hooks and do work soon.
"""
spec = node.gateway.spec
spec.id = None
self.nodemanager.group.allocate_id(spec)
node = self.nodemanager.setup_node(spec, self.queue.put)
self._active_nodes.add(node)
return node
def _failed_worker_collectreport(self, node, rep):
# Check we haven't already seen this report (from
# another worker).
if rep.longrepr not in self._failed_collection_errors:
self._failed_collection_errors[rep.longrepr] = True
self.config.hook.pytest_collectreport(report=rep)
self._handlefailures(rep)
def _handlefailures(self, rep):
if rep.failed:
self.countfailures += 1
if (
self.maxfail
and self.countfailures >= self.maxfail
and not self.shouldstop
):
self.shouldstop = f"stopping after {self.countfailures} failures"
def triggershutdown(self):
if not self.shuttingdown:
self.log("triggering shutdown")
self.shuttingdown = True
for node in self.sched.nodes:
node.shutdown()
def handle_crashitem(self, nodeid, worker):
# XXX get more reporting info by recording pytest_runtest_logstart?
# XXX count no of failures and retry N times
fspath = nodeid.split("::")[0]
msg = f"worker {worker.gateway.id!r} crashed while running {nodeid!r}"
rep = pytest.TestReport(
nodeid, (fspath, None, fspath), (), "failed", msg, "???"
)
rep.node = worker
self.config.hook.pytest_handlecrashitem(
crashitem=nodeid,
report=rep,
sched=self.sched,
)
self.config.hook.pytest_runtest_logreport(report=rep)
class WorkerStatus(Enum):
"""Status of each worker during creation/collection."""
# Worker spec has just been created.
Created = auto()
# Worker has been initialized.
Initialized = auto()
# Worker is now ready for collection.
ReadyForCollection = auto()
# Worker has finished collection.
CollectionDone = auto()
class TerminalDistReporter:
def __init__(self, config) -> None:
self.config = config
self.tr = config.pluginmanager.getplugin("terminalreporter")
self._status: dict[str, tuple[WorkerStatus, int]] = {}
self._lastlen = 0
self._isatty = getattr(self.tr, "isatty", self.tr.hasmarkup)
def write_line(self, msg: str) -> None:
self.tr.write_line(msg)
def ensure_show_status(self) -> None:
if not self._isatty:
self.write_line(self.getstatus())
def setstatus(
self, spec, status: WorkerStatus, *, tests_collected: int, show: bool = True
) -> None:
self._status[spec.id] = (status, tests_collected)
if show and self._isatty:
self.rewrite(self.getstatus())
def getstatus(self) -> str:
if self.config.option.verbose >= 0:
line = get_workers_status_line(list(self._status.values()))
if line:
return line
return "bringing up nodes..."
def rewrite(self, line, newline=False):
pline = line + " " * max(self._lastlen - len(line), 0)
if newline:
self._lastlen = 0
pline += "\n"
else:
self._lastlen = len(line)
self.tr.rewrite(pline, bold=True)
@pytest.hookimpl
def pytest_xdist_setupnodes(self, specs) -> None:
self._specs = specs
for spec in specs:
self.setstatus(spec, WorkerStatus.Created, tests_collected=0, show=False)
self.setstatus(spec, WorkerStatus.Created, tests_collected=0, show=True)
self.ensure_show_status()
@pytest.hookimpl
def pytest_xdist_newgateway(self, gateway) -> None:
if self.config.option.verbose > 0:
rinfo = gateway._rinfo()
different_interpreter = rinfo.executable != sys.executable
if different_interpreter:
version = "{}.{}.{}".format(*rinfo.version_info[:3])
self.rewrite(
f"[{gateway.id}] {rinfo.platform} Python {version} cwd: {rinfo.cwd}",
newline=True,
)
self.setstatus(gateway.spec, WorkerStatus.Initialized, tests_collected=0)
@pytest.hookimpl
def pytest_testnodeready(self, node) -> None:
if self.config.option.verbose > 0:
d = node.workerinfo
different_interpreter = d.get("executable") != sys.executable
if different_interpreter:
version = d["version"].replace("\n", " -- ")
self.rewrite(f"[{d['id']}] Python {version}", newline=True)
self.setstatus(
node.gateway.spec, WorkerStatus.ReadyForCollection, tests_collected=0
)
@pytest.hookimpl
def pytest_testnodedown(self, node, error) -> None:
if not error:
return
self.write_line(f"[{node.gateway.id}] node down: {error}")
def get_default_max_worker_restart(config):
"""Gets the default value of --max-worker-restart option if it is not provided.
Use a reasonable default to avoid workers from restarting endlessly due to crashing collections (#226).
"""
result = config.option.maxworkerrestart
if result is not None:
result = int(result)
elif config.option.numprocesses:
# if --max-worker-restart was not provided, use a reasonable default (#226)
result = config.option.numprocesses * 4
return result
def get_workers_status_line(
status_and_items: Sequence[tuple[WorkerStatus, int]],
) -> str:
"""
Return the line to display during worker setup/collection based on the
status of the workers and number of tests collected for each.
"""
statuses = [s for s, c in status_and_items]
total_workers = len(statuses)
workers_noun = "worker" if total_workers == 1 else "workers"
if status_and_items and all(s == WorkerStatus.CollectionDone for s in statuses):
# All workers collect the same number of items, so we grab
# the total number of items from the first worker.
first = status_and_items[0]
status, tests_collected = first
tests_noun = "item" if tests_collected == 1 else "items"
return f"{total_workers} {workers_noun} [{tests_collected} {tests_noun}]"
if WorkerStatus.CollectionDone in statuses:
done = sum(1 for s, c in status_and_items if c > 0)
return f"collecting: {done}/{total_workers} {workers_noun}"
if WorkerStatus.ReadyForCollection in statuses:
ready = statuses.count(WorkerStatus.ReadyForCollection)
return f"ready: {ready}/{total_workers} {workers_noun}"
if WorkerStatus.Initialized in statuses:
initialized = statuses.count(WorkerStatus.Initialized)
return f"initialized: {initialized}/{total_workers} {workers_noun}"
if WorkerStatus.Created in statuses:
created = statuses.count(WorkerStatus.Created)
return f"created: {created}/{total_workers} {workers_noun}"
return ""