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Posted to commits@buildstream.apache.org by tv...@apache.org on 2021/02/04 07:13:51 UTC
[buildstream] branch bschubert/no-multiprocessing-bak created (now
f26ab9f)
This is an automated email from the ASF dual-hosted git repository.
tvb pushed a change to branch bschubert/no-multiprocessing-bak
in repository https://gitbox.apache.org/repos/asf/buildstream.git.
at f26ab9f job.py: Completely remove the need for a queue between parent and child jobs
This branch includes the following new commits:
new 090b027 _signals.py: allow calling signal handler from non-main threads
new 4c03165 _fixtures.py: Only get the normal number of threads at the start of session
new ad9073a scheduler.py: Use threads instead of processes for jobs
new 31ec0cf _messenger.py: Make `timed_suspendable` public and use it in job.py
new ee93c58 job.py: Remove 'SUBCLASS_CUSTOM_MESSAGE', it is never used
new aaf2fcd job.py: Remove the ability to send back child data
new 0904e74 _messenger.py: Add type annotations on the module to help refactors
new 6ea36b0 _messenger.py: Extract job-specific actions into another class
new 82197de _messenger.py: Introduce a 'root' message handler
new 00659de job.py: Dont' pass the errors through the queue, we can set it directly
new f26ab9f job.py: Completely remove the need for a queue between parent and child jobs
The 11 revisions listed above as "new" are entirely new to this
repository and will be described in separate emails. The revisions
listed as "add" were already present in the repository and have only
been added to this reference.
[buildstream] 02/11: _fixtures.py: Only get the normal number of
threads at the start of session
Posted by tv...@apache.org.
This is an automated email from the ASF dual-hosted git repository.
tvb pushed a commit to branch bschubert/no-multiprocessing-bak
in repository https://gitbox.apache.org/repos/asf/buildstream.git
commit 4c03165bae69a027bd81bffe5fb33e03caa64cdf
Author: Benjamin Schubert <co...@benschubert.me>
AuthorDate: Fri Jul 3 12:47:14 2020 +0000
_fixtures.py: Only get the normal number of threads at the start of session
This ensures that we also have our tests correctly shutting down
background threads and not interferring with each other
---
src/buildstream/testing/_fixtures.py | 17 ++++++++++++-----
src/buildstream/testing/_sourcetests/conftest.py | 2 +-
tests/conftest.py | 6 +++++-
3 files changed, 18 insertions(+), 7 deletions(-)
diff --git a/src/buildstream/testing/_fixtures.py b/src/buildstream/testing/_fixtures.py
index 5da51bb..5d1c1d2 100644
--- a/src/buildstream/testing/_fixtures.py
+++ b/src/buildstream/testing/_fixtures.py
@@ -14,19 +14,26 @@
# You should have received a copy of the GNU Lesser General Public
# License along with this library. If not, see <http://www.gnu.org/licenses/>.
+# pylint: disable=redefined-outer-name
+
import psutil
import pytest
-from buildstream import node, utils
+from buildstream import node, utils, DownloadableFileSource
-# Catch tests that don't shut down background threads, which could then lead
-# to other tests hanging when BuildStream uses fork().
-@pytest.fixture(autouse=True)
-def thread_check():
+
+@pytest.fixture(autouse=True, scope="session")
+def default_thread_number():
# xdist/execnet has its own helper thread.
# Ignore that for `utils._is_single_threaded` checks.
utils._INITIAL_NUM_THREADS_IN_MAIN_PROCESS = psutil.Process().num_threads()
+
+# Catch tests that don't shut down background threads, which could then lead
+# to other tests hanging when BuildStream uses fork().
+@pytest.fixture(autouse=True)
+def thread_check(default_thread_number):
+ assert utils._is_single_threaded()
yield
assert utils._is_single_threaded()
diff --git a/src/buildstream/testing/_sourcetests/conftest.py b/src/buildstream/testing/_sourcetests/conftest.py
index 64dd404..6790712 100644
--- a/src/buildstream/testing/_sourcetests/conftest.py
+++ b/src/buildstream/testing/_sourcetests/conftest.py
@@ -14,4 +14,4 @@
# You should have received a copy of the GNU Lesser General Public
# License along with this library. If not, see <http://www.gnu.org/licenses/>.
-from .._fixtures import reset_global_node_state, thread_check # pylint: disable=unused-import
+from .._fixtures import reset_global_node_state, default_thread_number, thread_check # pylint: disable=unused-import
diff --git a/tests/conftest.py b/tests/conftest.py
index bb4611a..1faa4ce 100755
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -25,7 +25,11 @@ import pkg_resources
import pytest
from buildstream.testing import register_repo_kind, sourcetests_collection_hook
-from buildstream.testing._fixtures import reset_global_node_state, thread_check # pylint: disable=unused-import
+from buildstream.testing._fixtures import ( # pylint: disable=unused-import
+ default_thread_number,
+ reset_global_node_state,
+ thread_check,
+)
from buildstream.testing.integration import integration_cache # pylint: disable=unused-import
[buildstream] 10/11: job.py: Dont' pass the errors through the
queue, we can set it directly
Posted by tv...@apache.org.
This is an automated email from the ASF dual-hosted git repository.
tvb pushed a commit to branch bschubert/no-multiprocessing-bak
in repository https://gitbox.apache.org/repos/asf/buildstream.git
commit 00659deff4a391e93d395ac353a0ecfb36af66a4
Author: Benjamin Schubert <co...@benschubert.me>
AuthorDate: Wed Jul 8 10:05:54 2020 +0000
job.py: Dont' pass the errors through the queue, we can set it directly
We are now running in threads so we can set the global ourselves without
having to go through all the current hoops
---
src/buildstream/_scheduler/jobs/job.py | 28 ++--------------------------
1 file changed, 2 insertions(+), 26 deletions(-)
diff --git a/src/buildstream/_scheduler/jobs/job.py b/src/buildstream/_scheduler/jobs/job.py
index adff992..b253c1b 100644
--- a/src/buildstream/_scheduler/jobs/job.py
+++ b/src/buildstream/_scheduler/jobs/job.py
@@ -67,7 +67,6 @@ class _Envelope:
class _MessageType(FastEnum):
- ERROR = 2
RESULT = 3
@@ -387,12 +386,6 @@ class Job:
def _parent_process_envelope(self, envelope):
if not self._listening:
return
-
- elif envelope.message_type is _MessageType.ERROR:
- # For regression tests only, save the last error domain / reason
- # reported from a child task in the main process, this global state
- # is currently managed in _exceptions.py
- set_last_task_error(envelope.message["domain"], envelope.message["reason"])
elif envelope.message_type is _MessageType.RESULT:
assert self._result is None
self._result = envelope.message
@@ -572,8 +565,8 @@ class ChildJob:
MessageType.FAIL, str(e), elapsed=elapsed, detail=e.detail, logfile=filename, sandbox=e.sandbox
)
- # Report the exception to the parent (for internal testing purposes)
- self._child_send_error(e)
+ # Register the error for internal testing purposes
+ set_last_task_error(e.domain, e.reason)
# Set return code based on whether or not the error was temporary.
#
@@ -623,23 +616,6 @@ class ChildJob:
def _send_message(self, message_type, message_data):
self._pipe_w.send(_Envelope(message_type, message_data))
- # _child_send_error()
- #
- # Sends an error to the main process through the message pipe
- #
- # Args:
- # e (Exception): The error to send
- #
- def _child_send_error(self, e):
- domain = None
- reason = None
-
- if isinstance(e, BstError):
- domain = e.domain
- reason = e.reason
-
- self._send_message(_MessageType.ERROR, {"domain": domain, "reason": reason})
-
# _child_send_result()
#
# Sends the serialized result to the main process through the message pipe
[buildstream] 05/11: job.py: Remove 'SUBCLASS_CUSTOM_MESSAGE',
it is never used
Posted by tv...@apache.org.
This is an automated email from the ASF dual-hosted git repository.
tvb pushed a commit to branch bschubert/no-multiprocessing-bak
in repository https://gitbox.apache.org/repos/asf/buildstream.git
commit ee93c582fd91d0d9e8991a666e473162cd947b12
Author: Benjamin Schubert <co...@benschubert.me>
AuthorDate: Mon Jul 6 18:52:21 2020 +0000
job.py: Remove 'SUBCLASS_CUSTOM_MESSAGE', it is never used
---
src/buildstream/_scheduler/jobs/job.py | 38 ----------------------------------
1 file changed, 38 deletions(-)
diff --git a/src/buildstream/_scheduler/jobs/job.py b/src/buildstream/_scheduler/jobs/job.py
index 03a6b61..29f2e36 100644
--- a/src/buildstream/_scheduler/jobs/job.py
+++ b/src/buildstream/_scheduler/jobs/job.py
@@ -71,7 +71,6 @@ class _MessageType(FastEnum):
ERROR = 2
RESULT = 3
CHILD_DATA = 4
- SUBCLASS_CUSTOM_MESSAGE = 5
# Job()
@@ -273,22 +272,6 @@ class Job:
# Abstract Methods #
#######################################################
- # handle_message()
- #
- # Handle a custom message. This will be called in the main process in
- # response to any messages sent to the main process using the
- # Job.send_message() API from inside a Job.child_process() implementation.
- #
- # There is no need to implement this function if no custom messages are
- # expected.
- #
- # Args:
- # message (any): A simple object (must be pickle-able, i.e. strings,
- # lists, dicts, numbers, but not Element instances).
- #
- def handle_message(self, message):
- raise ImplError("Job '{kind}' does not implement handle_message()".format(kind=type(self).__name__))
-
# parent_complete()
#
# This will be executed in the main process after the job finishes, and is
@@ -423,8 +406,6 @@ class Job:
elif envelope.message_type is _MessageType.CHILD_DATA:
# If we retry a job, we assign a new value to this
self.child_data = envelope.message
- elif envelope.message_type is _MessageType.SUBCLASS_CUSTOM_MESSAGE:
- self.handle_message(envelope.message)
else:
assert False, "Unhandled message type '{}': {}".format(envelope.message_type, envelope.message)
@@ -536,25 +517,6 @@ class ChildJob:
Message(message_type, message, element_name=element_name, element_key=element_key, **kwargs)
)
- # send_message()
- #
- # Send data in a message to the parent Job, running in the main process.
- #
- # This allows for custom inter-process communication between subclasses of
- # Job and ChildJob.
- #
- # These messages will be processed by the Job.handle_message()
- # implementation, which may be overridden to support one or more custom
- # 'message_type's.
- #
- # Args:
- # message_data (any): A simple object (must be pickle-able, i.e.
- # strings, lists, dicts, numbers, but not Element
- # instances). This is sent to the parent Job.
- #
- def send_message(self, message_data):
- self._send_message(_MessageType.SUBCLASS_CUSTOM_MESSAGE, message_data)
-
#######################################################
# Abstract Methods #
#######################################################
[buildstream] 11/11: job.py: Completely remove the need for a queue
between parent and child jobs
Posted by tv...@apache.org.
This is an automated email from the ASF dual-hosted git repository.
tvb pushed a commit to branch bschubert/no-multiprocessing-bak
in repository https://gitbox.apache.org/repos/asf/buildstream.git
commit f26ab9fdbbfc297a7ddea7a7b2312573273f4b73
Author: Benjamin Schubert <co...@benschubert.me>
AuthorDate: Wed Jul 8 12:02:28 2020 +0000
job.py: Completely remove the need for a queue between parent and child jobs
We don't need that distinction anymore
---
src/buildstream/_scheduler/jobs/job.py | 160 +++------------------------------
1 file changed, 12 insertions(+), 148 deletions(-)
diff --git a/src/buildstream/_scheduler/jobs/job.py b/src/buildstream/_scheduler/jobs/job.py
index b253c1b..1ce66f6 100644
--- a/src/buildstream/_scheduler/jobs/job.py
+++ b/src/buildstream/_scheduler/jobs/job.py
@@ -23,7 +23,6 @@
# System imports
import asyncio
import datetime
-import multiprocessing
import traceback
# BuildStream toplevel imports
@@ -59,17 +58,6 @@ class JobStatus(FastEnum):
SKIPPED = 3
-# Used to distinguish between status messages and return values
-class _Envelope:
- def __init__(self, message_type, message):
- self.message_type = message_type
- self.message = message
-
-
-class _MessageType(FastEnum):
- RESULT = 3
-
-
# Job()
#
# The Job object represents a task that will run in parallel to the main
@@ -119,9 +107,6 @@ class Job:
#
self._scheduler = scheduler # The scheduler
self._messenger = self._scheduler.context.messenger
- self._pipe_r = None # The read end of a pipe for message passing
- self._listening = False # Whether the parent is currently listening
- self._suspended = False # Whether this job is currently suspended
self._max_retries = max_retries # Maximum number of automatic retries
self._result = None # Return value of child action in the parent
self._tries = 0 # Try count, for retryable jobs
@@ -148,11 +133,7 @@ class Job:
assert not self._terminated, "Attempted to start process which was already terminated"
- # FIXME: remove this, this is not necessary when using asyncio
- self._pipe_r, pipe_w = multiprocessing.Pipe(duplex=False)
-
self._tries += 1
- self._parent_start_listening()
# FIXME: remove the parent/child separation, it's not needed anymore.
child_job = self.create_child_job( # pylint: disable=assignment-from-no-return
@@ -170,12 +151,13 @@ class Job:
async def execute():
try:
- result = await loop.run_in_executor(None, child_job.child_action, pipe_w)
+ ret_code, self._result = await loop.run_in_executor(None, child_job.child_action)
except asyncio.CancelledError:
- result = _ReturnCode.TERMINATED
+ ret_code = _ReturnCode.TERMINATED
except Exception: # pylint: disable=broad-except
- result = _ReturnCode.FAIL
- await self._parent_child_completed(result)
+ traceback.print_exc()
+ ret_code = _ReturnCode.FAIL
+ await self._parent_child_completed(ret_code)
self._task = loop.create_task(execute())
@@ -188,9 +170,6 @@ class Job:
def terminate(self):
self.message(MessageType.STATUS, "{} terminating".format(self.action_name))
- # Make sure there is no garbage on the pipe
- self._parent_stop_listening()
-
# Terminate the process using multiprocessing API pathway
if self._task:
self._task.cancel()
@@ -302,16 +281,6 @@ class Job:
# Local Private Methods #
#######################################################
- # _parent_shutdown()
- #
- # Shuts down the Job on the parent side by reading any remaining
- # messages on the message pipe and cleaning up any resources.
- #
- def _parent_shutdown(self):
- # Make sure we've read everything we need and then stop listening
- self._parent_process_pipe()
- self._parent_stop_listening()
-
# _parent_child_completed()
#
# Called in the main process courtesy of asyncio's ChildWatcher.add_child_handler()
@@ -320,8 +289,6 @@ class Job:
# returncode (int): The return code of the child process
#
async def _parent_child_completed(self, returncode):
- self._parent_shutdown()
-
try:
returncode = _ReturnCode(returncode)
except ValueError:
@@ -368,69 +335,7 @@ class Job:
self.parent_complete(status, self._result)
self._scheduler.job_completed(self, status)
- # Force the deletion of the pipe and process objects to try and clean up FDs
- self._pipe_r.close()
- self._pipe_r = self._task = None
-
- # _parent_process_envelope()
- #
- # Processes a message Envelope deserialized form the message pipe.
- #
- # this will have the side effect of assigning some local state
- # on the Job in the parent process for later inspection when the
- # child process completes.
- #
- # Args:
- # envelope (Envelope): The message envelope
- #
- def _parent_process_envelope(self, envelope):
- if not self._listening:
- return
- elif envelope.message_type is _MessageType.RESULT:
- assert self._result is None
- self._result = envelope.message
- else:
- assert False, "Unhandled message type '{}': {}".format(envelope.message_type, envelope.message)
-
- # _parent_process_pipe()
- #
- # Reads back message envelopes from the message pipe
- # in the parent process.
- #
- def _parent_process_pipe(self):
- while self._pipe_r.poll():
- try:
- envelope = self._pipe_r.recv()
- except EOFError:
- self._parent_stop_listening()
- break
- self._parent_process_envelope(envelope)
-
- # _parent_recv()
- #
- # A callback to handle I/O events from the message
- # pipe file descriptor in the main process message loop
- #
- def _parent_recv(self, *args):
- self._parent_process_pipe()
-
- # _parent_start_listening()
- #
- # Starts listening on the message pipe
- #
- def _parent_start_listening(self):
- if not self._listening:
- self._scheduler.loop.add_reader(self._pipe_r.fileno(), self._parent_recv)
- self._listening = True
-
- # _parent_stop_listening()
- #
- # Stops listening on the message pipe
- #
- def _parent_stop_listening(self):
- if self._listening:
- self._scheduler.loop.remove_reader(self._pipe_r.fileno())
- self._listening = False
+ self._task = None
# ChildJob()
@@ -471,8 +376,6 @@ class ChildJob:
self._message_element_name = message_element_name
self._message_element_key = message_element_key
- self._pipe_w = None # The write end of a pipe for message passing
-
# message():
#
# Logs a message, this will be logged in the task's logfile and
@@ -525,12 +428,7 @@ class ChildJob:
# Args:
# pipe_w (multiprocessing.connection.Connection): The message pipe for IPC
#
- def child_action(self, pipe_w):
- # Assign the pipe we passed across the process boundaries
- #
- # Set the global message handler in this child
- # process to forward messages to the parent process
- self._pipe_w = pipe_w
+ def child_action(self):
self._messenger.set_message_handler(self._child_message_handler)
# Time, log and and run the action function
@@ -548,7 +446,7 @@ class ChildJob:
self.message(MessageType.SKIPPED, str(e), elapsed=elapsed, logfile=filename)
# Alert parent of skip by return code
- return _ReturnCode.SKIPPED
+ return _ReturnCode.SKIPPED, None
except BstError as e:
elapsed = datetime.datetime.now() - timeinfo.start_time
retry_flag = e.temporary
@@ -570,11 +468,11 @@ class ChildJob:
# Set return code based on whether or not the error was temporary.
#
- return _ReturnCode.FAIL if retry_flag else _ReturnCode.PERM_FAIL
+ return _ReturnCode.FAIL if retry_flag else _ReturnCode.PERM_FAIL, None
except Exception: # pylint: disable=broad-except
- # If an unhandled (not normalized to BstError) occurs, that's a bug,
+ # If an unhandled (not normalized to BstError) occurs, that's a `bug`,
# send the traceback and formatted exception back to the frontend
# and print it to the log file.
#
@@ -583,55 +481,21 @@ class ChildJob:
self.message(MessageType.BUG, self.action_name, elapsed=elapsed, detail=detail, logfile=filename)
# Unhandled exceptions should permenantly fail
- return _ReturnCode.PERM_FAIL
+ return _ReturnCode.PERM_FAIL, None
else:
- # No exception occurred in the action
- self._child_send_result(result)
-
elapsed = datetime.datetime.now() - timeinfo.start_time
self.message(MessageType.SUCCESS, self.action_name, elapsed=elapsed, logfile=filename)
# Shutdown needs to stay outside of the above context manager,
# make sure we dont try to handle SIGTERM while the process
# is already busy in sys.exit()
- return _ReturnCode.OK
- finally:
- self._pipe_w.close()
+ return _ReturnCode.OK, result
#######################################################
# Local Private Methods #
#######################################################
- # _send_message()
- #
- # Send data in a message to the parent Job, running in the main process.
- #
- # Args:
- # message_type (str): The type of message to send.
- # message_data (any): A simple object (must be pickle-able, i.e.
- # strings, lists, dicts, numbers, but not Element
- # instances). This is sent to the parent Job.
- #
- def _send_message(self, message_type, message_data):
- self._pipe_w.send(_Envelope(message_type, message_data))
-
- # _child_send_result()
- #
- # Sends the serialized result to the main process through the message pipe
- #
- # Args:
- # result (any): None, or a simple object (must be pickle-able, i.e.
- # strings, lists, dicts, numbers, but not Element
- # instances).
- #
- # Note: If None is passed here, nothing needs to be sent, the
- # result member in the parent process will simply remain None.
- #
- def _child_send_result(self, result):
- if result is not None:
- self._send_message(_MessageType.RESULT, result)
-
# _child_message_handler()
#
# A Context delegate for handling messages, this replaces the
[buildstream] 09/11: _messenger.py: Introduce a 'root' message
handler
Posted by tv...@apache.org.
This is an automated email from the ASF dual-hosted git repository.
tvb pushed a commit to branch bschubert/no-multiprocessing-bak
in repository https://gitbox.apache.org/repos/asf/buildstream.git
commit 82197ded517fd2a37370de58d0c65043cb33084b
Author: Benjamin Schubert <co...@benschubert.me>
AuthorDate: Tue Jul 7 22:37:27 2020 +0100
_messenger.py: Introduce a 'root' message handler
This is to be set in the main process and allows jobs to explicitely
send a message back to the main handler
---
src/buildstream/_frontend/app.py | 2 +-
src/buildstream/_messenger.py | 25 ++++++++++++++++++++++---
src/buildstream/_scheduler/jobs/job.py | 7 +------
tests/testutils/context.py | 2 +-
4 files changed, 25 insertions(+), 11 deletions(-)
diff --git a/src/buildstream/_frontend/app.py b/src/buildstream/_frontend/app.py
index 3160e8b..05d2491 100644
--- a/src/buildstream/_frontend/app.py
+++ b/src/buildstream/_frontend/app.py
@@ -240,7 +240,7 @@ class App:
)
# Propagate pipeline feedback to the user
- self.context.messenger.set_message_handler(self._message_handler)
+ self.context.messenger.set_root_message_handler(self._message_handler)
# Check if throttling frontend updates to tick rate
self._cache_messages = self.context.log_throttle_updates
diff --git a/src/buildstream/_messenger.py b/src/buildstream/_messenger.py
index e6456ef..f93e0ad 100644
--- a/src/buildstream/_messenger.py
+++ b/src/buildstream/_messenger.py
@@ -210,6 +210,8 @@ class Messenger:
self._active_simple_tasks: int = 0
self._render_status_cb: Optional[Callable[[], None]] = None
+ self._root_message_handler: Optional[_MessageHandler] = None
+
self._locals = threading.local()
self._locals.message_handler = None
@@ -224,6 +226,18 @@ class Messenger:
def set_message_handler(self, handler: MessageHandlerCallback) -> None:
self._locals.message_handler = _MessageHandler(handler)
+ # set_root_message_handler()
+ #
+ # Sets the handler for any status messages propagated through
+ # the context.
+ #
+ # Args:
+ # handler: The handler to call on message
+ #
+ def set_root_message_handler(self, handler: MessageHandlerCallback) -> None:
+ self._root_message_handler = _MessageHandler(handler)
+ self._locals.message_handler = self._root_message_handler
+
# set_state()
#
# Sets the State object within the Messenger
@@ -251,9 +265,14 @@ class Messenger:
#
# Args:
# message: A Message object
- #
- def message(self, message: Message) -> None:
- self._message_handler.message(message)
+ # use_root_handler: Whether to use the root handler or the thread local one
+ #
+ def message(self, message: Message, use_root_handler: bool = False) -> None:
+ if use_root_handler:
+ assert self._root_message_handler is not None
+ self._root_message_handler.message(message)
+ else:
+ self._message_handler.message(message)
# silence()
#
diff --git a/src/buildstream/_scheduler/jobs/job.py b/src/buildstream/_scheduler/jobs/job.py
index f331d3f..adff992 100644
--- a/src/buildstream/_scheduler/jobs/job.py
+++ b/src/buildstream/_scheduler/jobs/job.py
@@ -67,7 +67,6 @@ class _Envelope:
class _MessageType(FastEnum):
- LOG_MESSAGE = 1
ERROR = 2
RESULT = 3
@@ -389,10 +388,6 @@ class Job:
if not self._listening:
return
- if envelope.message_type is _MessageType.LOG_MESSAGE:
- # Propagate received messages from children
- # back through the context.
- self._messenger.message(envelope.message)
elif envelope.message_type is _MessageType.ERROR:
# For regression tests only, save the last error domain / reason
# reported from a child task in the main process, this global state
@@ -691,4 +686,4 @@ class ChildJob:
if message.message_type == MessageType.LOG:
return
- self._send_message(_MessageType.LOG_MESSAGE, message)
+ self._messenger.message(message, use_root_handler=True)
diff --git a/tests/testutils/context.py b/tests/testutils/context.py
index 821adef..6850c00 100644
--- a/tests/testutils/context.py
+++ b/tests/testutils/context.py
@@ -74,7 +74,7 @@ def dummy_context(*, config=None):
context.load(config=config)
- context.messenger.set_message_handler(_dummy_message_handler)
+ context.messenger.set_root_message_handler(_dummy_message_handler)
context.messenger.simple_task = MethodType(_get_dummy_task, context.messenger)
yield context
[buildstream] 07/11: _messenger.py: Add type annotations on the
module to help refactors
Posted by tv...@apache.org.
This is an automated email from the ASF dual-hosted git repository.
tvb pushed a commit to branch bschubert/no-multiprocessing-bak
in repository https://gitbox.apache.org/repos/asf/buildstream.git
commit 0904e74e1e1f20adec530c2bc84b6efa59423c9b
Author: Benjamin Schubert <co...@benschubert.me>
AuthorDate: Tue Jul 7 18:51:36 2020 +0000
_messenger.py: Add type annotations on the module to help refactors
---
src/buildstream/_messenger.py | 125 ++++++++++++++++++++++--------------------
1 file changed, 66 insertions(+), 59 deletions(-)
diff --git a/src/buildstream/_messenger.py b/src/buildstream/_messenger.py
index 84bea6a..fc9bd72 100644
--- a/src/buildstream/_messenger.py
+++ b/src/buildstream/_messenger.py
@@ -1,5 +1,5 @@
#
-# Copyright (C) 2019 Bloomberg Finance LP
+# Copyright (C) 2019-2020 Bloomberg Finance LP
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
@@ -21,10 +21,12 @@ import os
import datetime
import threading
from contextlib import contextmanager
+from typing import Callable, Generator, Optional
from . import _signals
from ._exceptions import BstError
from ._message import Message, MessageType
+from ._state import State, _Task
_RENDER_INTERVAL = datetime.timedelta(seconds=1)
@@ -42,16 +44,21 @@ if "BST_TEST_SUITE" in os.environ:
class _TimeData:
__slots__ = ["start_time"]
- def __init__(self, start_time):
+ def __init__(self, start_time: datetime.datetime) -> None:
self.start_time = start_time
+class MessageHandlerCallback:
+ def __call__(self, message: Message, is_silenced: bool) -> None:
+ pass
+
+
class Messenger:
- def __init__(self):
- self._state = None
- self._next_render = None # A Time object
- self._active_simple_tasks = 0
- self._render_status_cb = None
+ def __init__(self) -> None:
+ self._state: Optional[State] = None
+ self._next_render: Optional[datetime.datetime] = None # A Time object
+ self._active_simple_tasks: int = 0
+ self._render_status_cb: Optional[Callable[[], None]] = None
self._locals = threading.local()
self._locals.message_handler = None
@@ -64,14 +71,10 @@ class Messenger:
# Sets the handler for any status messages propagated through
# the context.
#
- # The handler should have the signature:
- #
- # def handler(
- # message: _message.Message, # The message to send.
- # is_silenced: bool, # Whether messages are currently being silenced.
- # ) -> None
+ # Args:
+ # handler: The handler to call on message
#
- def set_message_handler(self, handler):
+ def set_message_handler(self, handler: MessageHandlerCallback) -> None:
self._locals.message_handler = handler
# set_state()
@@ -79,9 +82,9 @@ class Messenger:
# Sets the State object within the Messenger
#
# Args:
- # state (State): The state to set
+ # state: The state to set
#
- def set_state(self, state):
+ def set_state(self, state: State) -> None:
self._state = state
# set_render_status_cb()
@@ -89,20 +92,16 @@ class Messenger:
# Sets the callback to use to render status
#
# Args:
- # callback (function): The Callback to be notified
+ # callback: The Callback to be notified
#
- # Callback Args:
- # There are no arguments to the callback
- #
- def set_render_status_cb(self, callback):
+ def set_render_status_cb(self, callback: Callable[[], None]) -> None:
self._render_status_cb = callback
# _silent_messages():
#
- # Returns:
- # (bool): Whether messages are currently being silenced
+ # Returns: Whether messages are currently being silenced
#
- def _silent_messages(self):
+ def _silent_messages(self) -> bool:
return self._locals.silence_scope_depth > 0
# message():
@@ -113,7 +112,7 @@ class Messenger:
# Args:
# message: A Message object
#
- def message(self, message):
+ def message(self, message: Message) -> None:
# If we are recording messages, dump a copy into the open log file.
self._record_message(message)
@@ -132,12 +131,11 @@ class Messenger:
# _message.unconditional_messages will be silenced.
#
# Args:
- # actually_silence (bool): Whether to actually do the silencing, if
- # False then this context manager does not
- # affect anything.
+ # actually_silence: Whether to actually do the silencing, if False then
+ # this context manager does not affect anything.
#
@contextmanager
- def silence(self, *, actually_silence=True):
+ def silence(self, *, actually_silence: bool = True) -> Generator[None, None, None]:
if not actually_silence:
yield
return
@@ -154,13 +152,20 @@ class Messenger:
# Context manager for performing timed activities and logging those
#
# Args:
- # activity_name (str): The name of the activity
- # element_name (str): Optionally, the element full name of the plugin related to the message
- # detail (str): An optional detailed message, can be multiline output
- # silent_nested (bool): If True, all but _message.unconditional_messages are silenced
+ # activity_name: The name of the activity
+ # element_name: Optionally, the element full name of the plugin related to the message
+ # detail: An optional detailed message, can be multiline output
+ # silent_nested: If True, all but _message.unconditional_messages are silenced
#
@contextmanager
- def timed_activity(self, activity_name, *, element_name=None, detail=None, silent_nested=False):
+ def timed_activity(
+ self,
+ activity_name: str,
+ *,
+ element_name: Optional[str] = None,
+ detail: Optional[str] = None,
+ silent_nested: bool = False
+ ) -> Generator[None, None, None]:
with self.timed_suspendable() as timedata:
try:
# Push activity depth for status messages
@@ -186,20 +191,26 @@ class Messenger:
# Context manager for creating a task to report progress to.
#
# Args:
- # activity_name (str): The name of the activity
- # element_name (str): Optionally, the element full name of the plugin related to the message
- # full_name (str): Optionally, the distinguishing name of the activity, e.g. element name
- # silent_nested (bool): If True, all but _message.unconditional_messages are silenced
+ # activity_name: The name of the activity
+ # element_name: Optionally, the element full name of the plugin related to the message
+ # full_name: Optionally, the distinguishing name of the activity, e.g. element name
+ # silent_nested: If True, all but _message.unconditional_messages are silenced
#
- # Yields:
- # Task: A Task object that represents this activity, principally used to report progress
+ # Yields: A Task object that represents this activity, principally used to report progress
#
@contextmanager
- def simple_task(self, activity_name, *, element_name=None, full_name=None, silent_nested=False):
+ def simple_task(
+ self,
+ activity_name: str,
+ *,
+ element_name: Optional[str] = None,
+ full_name: Optional[str] = None,
+ silent_nested: bool = False
+ ) -> Generator[Optional[_Task], None, None]:
# Bypass use of State when none exists (e.g. tests)
if not self._state:
with self.timed_activity(activity_name, element_name=element_name, silent_nested=silent_nested):
- yield
+ yield None
return
if not full_name:
@@ -255,17 +266,15 @@ class Messenger:
# Messenger.get_log_filename() API.
#
# Args:
- # filename (str): A logging directory relative filename,
- # the pid and .log extension will be automatically
- # appended
+ # filename: A logging directory relative filename, the pid and .log
+ # extension will be automatically appended
#
- # logdir (str) : The path to the log file directory.
+ # logdir : The path to the log file directory.
#
- # Yields:
- # (str): The fully qualified log filename
+ # Yields: The fully qualified log filename
#
@contextmanager
- def recorded_messages(self, filename, logdir):
+ def recorded_messages(self, filename: str, logdir: str) -> Generator[str, None, None]:
# We dont allow recursing in this context manager, and
# we also do not allow it in the main process.
assert not hasattr(self._locals, "log_handle") or self._locals.log_handle is None
@@ -308,10 +317,9 @@ class Messenger:
# log file handle when the Messenger.recorded_messages() context
# manager is active
#
- # Returns:
- # (file): The active logging file handle, or None
+ # Returns: The active logging file handle, or None
#
- def get_log_handle(self):
+ def get_log_handle(self) -> str:
return self._locals.log_handle
# get_log_filename()
@@ -320,10 +328,9 @@ class Messenger:
# log filename when the Messenger.recorded_messages() context
# manager is active
#
- # Returns:
- # (str): The active logging filename, or None
+ # Returns: The active logging filename, or None
#
- def get_log_filename(self):
+ def get_log_filename(self) -> str:
return self._locals.log_filename
# timed_suspendable()
@@ -332,10 +339,10 @@ class Messenger:
# adjust for clock drift caused by suspending
#
# Yields:
- # TimeData: An object that contains the time the activity started
+ # An object that contains the time the activity started
#
@contextmanager
- def timed_suspendable(self):
+ def timed_suspendable(self) -> Generator[_TimeData, None, None]:
# Note: timedata needs to be in a namedtuple so that values can be
# yielded that will change
timedata = _TimeData(start_time=datetime.datetime.now())
@@ -361,7 +368,7 @@ class Messenger:
# Args:
# message (Message): The message to record
#
- def _record_message(self, message):
+ def _record_message(self, message: Message) -> None:
if self._locals.log_handle is None:
return
@@ -408,7 +415,7 @@ class Messenger:
# Calls the render status callback set in the messenger, but only if a
# second has passed since it last rendered.
#
- def _render_status(self):
+ def _render_status(self) -> None:
assert self._next_render
# self._render_status_cb()
[buildstream] 04/11: _messenger.py: Make `timed_suspendable` public
and use it in job.py
Posted by tv...@apache.org.
This is an automated email from the ASF dual-hosted git repository.
tvb pushed a commit to branch bschubert/no-multiprocessing-bak
in repository https://gitbox.apache.org/repos/asf/buildstream.git
commit 31ec0cf7279866d4e035eb662075a63c851ab91a
Author: Benjamin Schubert <co...@benschubert.me>
AuthorDate: Sat Jul 4 12:13:24 2020 +0000
_messenger.py: Make `timed_suspendable` public and use it in job.py
This reduces the amount of code duplication
---
src/buildstream/_messenger.py | 60 +++++++++++++++++-----------------
src/buildstream/_scheduler/jobs/job.py | 23 +++----------
2 files changed, 35 insertions(+), 48 deletions(-)
diff --git a/src/buildstream/_messenger.py b/src/buildstream/_messenger.py
index 222b05d..84bea6a 100644
--- a/src/buildstream/_messenger.py
+++ b/src/buildstream/_messenger.py
@@ -161,7 +161,7 @@ class Messenger:
#
@contextmanager
def timed_activity(self, activity_name, *, element_name=None, detail=None, silent_nested=False):
- with self._timed_suspendable() as timedata:
+ with self.timed_suspendable() as timedata:
try:
# Push activity depth for status messages
message = Message(MessageType.START, activity_name, detail=detail, element_name=element_name)
@@ -205,7 +205,7 @@ class Messenger:
if not full_name:
full_name = activity_name
- with self._timed_suspendable() as timedata:
+ with self.timed_suspendable() as timedata:
try:
message = Message(MessageType.START, activity_name, element_name=element_name)
self.message(message)
@@ -326,6 +326,34 @@ class Messenger:
def get_log_filename(self):
return self._locals.log_filename
+ # timed_suspendable()
+ #
+ # A contextmanager that allows an activity to be suspended and can
+ # adjust for clock drift caused by suspending
+ #
+ # Yields:
+ # TimeData: An object that contains the time the activity started
+ #
+ @contextmanager
+ def timed_suspendable(self):
+ # Note: timedata needs to be in a namedtuple so that values can be
+ # yielded that will change
+ timedata = _TimeData(start_time=datetime.datetime.now())
+ stopped_time = None
+
+ def stop_time():
+ nonlocal stopped_time
+ stopped_time = datetime.datetime.now()
+
+ def resume_time():
+ nonlocal timedata
+ nonlocal stopped_time
+ sleep_time = datetime.datetime.now() - stopped_time
+ timedata.start_time += sleep_time
+
+ with _signals.suspendable(stop_time, resume_time):
+ yield timedata
+
# _record_message()
#
# Records the message if recording is enabled
@@ -388,31 +416,3 @@ class Messenger:
if self._render_status_cb and now >= self._next_render:
self._render_status_cb()
self._next_render = now + _RENDER_INTERVAL
-
- # _timed_suspendable()
- #
- # A contextmanager that allows an activity to be suspended and can
- # adjust for clock drift caused by suspending
- #
- # Yields:
- # TimeData: An object that contains the time the activity started
- #
- @contextmanager
- def _timed_suspendable(self):
- # Note: timedata needs to be in a namedtuple so that values can be
- # yielded that will change
- timedata = _TimeData(start_time=datetime.datetime.now())
- stopped_time = None
-
- def stop_time():
- nonlocal stopped_time
- stopped_time = datetime.datetime.now()
-
- def resume_time():
- nonlocal timedata
- nonlocal stopped_time
- sleep_time = datetime.datetime.now() - stopped_time
- timedata.start_time += sleep_time
-
- with _signals.suspendable(stop_time, resume_time):
- yield timedata
diff --git a/src/buildstream/_scheduler/jobs/job.py b/src/buildstream/_scheduler/jobs/job.py
index a4ace41..03a6b61 100644
--- a/src/buildstream/_scheduler/jobs/job.py
+++ b/src/buildstream/_scheduler/jobs/job.py
@@ -30,7 +30,6 @@ import traceback
from ..._exceptions import ImplError, BstError, set_last_task_error, SkipJob
from ..._message import Message, MessageType, unconditional_messages
from ...types import FastEnum
-from ... import _signals
# Return code values shutdown of job handling child processes
@@ -603,21 +602,9 @@ class ChildJob:
self._pipe_w = pipe_w
self._messenger.set_message_handler(self._child_message_handler)
- starttime = datetime.datetime.now()
- stopped_time = None
-
- def stop_time():
- nonlocal stopped_time
- stopped_time = datetime.datetime.now()
-
- def resume_time():
- nonlocal stopped_time
- nonlocal starttime
- starttime += datetime.datetime.now() - stopped_time
-
# Time, log and and run the action function
#
- with _signals.suspendable(stop_time, resume_time), self._messenger.recorded_messages(
+ with self._messenger.timed_suspendable() as timeinfo, self._messenger.recorded_messages(
self._logfile, self._logdir
) as filename:
self.message(MessageType.START, self.action_name, logfile=filename)
@@ -626,13 +613,13 @@ class ChildJob:
# Try the task action
result = self.child_process() # pylint: disable=assignment-from-no-return
except SkipJob as e:
- elapsed = datetime.datetime.now() - starttime
+ elapsed = datetime.datetime.now() - timeinfo.start_time
self.message(MessageType.SKIPPED, str(e), elapsed=elapsed, logfile=filename)
# Alert parent of skip by return code
return _ReturnCode.SKIPPED
except BstError as e:
- elapsed = datetime.datetime.now() - starttime
+ elapsed = datetime.datetime.now() - timeinfo.start_time
retry_flag = e.temporary
if retry_flag and (self._tries <= self._max_retries):
@@ -662,7 +649,7 @@ class ChildJob:
# send the traceback and formatted exception back to the frontend
# and print it to the log file.
#
- elapsed = datetime.datetime.now() - starttime
+ elapsed = datetime.datetime.now() - timeinfo.start_time
detail = "An unhandled exception occured:\n\n{}".format(traceback.format_exc())
self.message(MessageType.BUG, self.action_name, elapsed=elapsed, detail=detail, logfile=filename)
@@ -674,7 +661,7 @@ class ChildJob:
self._send_message(_MessageType.CHILD_DATA, self.child_process_data())
self._child_send_result(result)
- elapsed = datetime.datetime.now() - starttime
+ elapsed = datetime.datetime.now() - timeinfo.start_time
self.message(MessageType.SUCCESS, self.action_name, elapsed=elapsed, logfile=filename)
# Shutdown needs to stay outside of the above context manager,
[buildstream] 08/11: _messenger.py: Extract job-specific actions
into another class
Posted by tv...@apache.org.
This is an automated email from the ASF dual-hosted git repository.
tvb pushed a commit to branch bschubert/no-multiprocessing-bak
in repository https://gitbox.apache.org/repos/asf/buildstream.git
commit 6ea36b0f65394c54c194e6a6ade6328725979e5a
Author: Benjamin Schubert <co...@benschubert.me>
AuthorDate: Tue Jul 7 19:36:56 2020 +0000
_messenger.py: Extract job-specific actions into another class
This will help separating concerns and have more explicit control on
what is happening where
---
src/buildstream/_messenger.py | 276 +++++++++++++++++++++++++-----------------
1 file changed, 164 insertions(+), 112 deletions(-)
diff --git a/src/buildstream/_messenger.py b/src/buildstream/_messenger.py
index fc9bd72..e6456ef 100644
--- a/src/buildstream/_messenger.py
+++ b/src/buildstream/_messenger.py
@@ -21,7 +21,7 @@ import os
import datetime
import threading
from contextlib import contextmanager
-from typing import Callable, Generator, Optional
+from typing import Callable, Generator, Optional, TextIO
from . import _signals
from ._exceptions import BstError
@@ -53,6 +53,156 @@ class MessageHandlerCallback:
pass
+class _MessageHandler:
+ def __init__(self, callback: MessageHandlerCallback) -> None:
+ self.log_handle: Optional[TextIO] = None
+ self.log_filename: Optional[str] = None
+
+ self._callback: MessageHandlerCallback = callback
+ self._silence_scope_depth: int = 0
+
+ # message():
+ #
+ # Handle the given message
+ #
+ # Args:
+ # message: A Message object
+ #
+ def message(self, message: Message) -> None:
+ # If we are recording messages, dump a copy into the open log file.
+ self._record_message(message)
+ self._callback(message, is_silenced=self._silent_messages())
+
+ # recorded_messages()
+ #
+ # Records all messages in a log file while the context manager
+ # is active.
+ #
+ # In addition to automatically writing all messages to the
+ # specified logging file, an open file handle for process stdout
+ # and stderr will be available via the Messenger.get_log_handle() API,
+ # and the full logfile path will be available via the
+ # Messenger.get_log_filename() API.
+ #
+ # Args:
+ # filename: A logging directory relative filename, the pid and .log
+ # extension will be automatically appended
+ #
+ # logdir : The path to the log file directory.
+ #
+ # Yields: The fully qualified log filename
+ #
+ @contextmanager
+ def recorded_messages(self, filename: str, logdir: str) -> Generator[str, None, None]:
+ # We dont allow recursing in this context manager, and
+ # we also do not allow it in the main process.
+ assert self.log_handle is None
+ assert self.log_filename is None
+
+ # Create the fully qualified logfile in the log directory,
+ # appending the pid and .log extension at the end.
+ self.log_filename = os.path.join(logdir, "{}.{}.log".format(filename, os.getpid()))
+ self._silence_scope_depth = 0
+
+ # Ensure the directory exists first
+ directory = os.path.dirname(self.log_filename)
+ os.makedirs(directory, exist_ok=True)
+
+ with open(self.log_filename, "a") as logfile:
+
+ # Write one last line to the log and flush it to disk
+ def flush_log():
+
+ # If the process currently had something happening in the I/O stack
+ # then trying to reenter the I/O stack will fire a runtime error.
+ #
+ # So just try to flush as well as we can at SIGTERM time
+ try:
+ logfile.write("\n\nForcefully terminated\n")
+ logfile.flush()
+ except RuntimeError:
+ os.fsync(logfile.fileno())
+
+ self.log_handle = logfile
+ with _signals.terminator(flush_log):
+ yield self.log_filename
+
+ self.log_handle = None
+ self.log_filename = None
+
+ # silence()
+ #
+ # A context manager to silence messages, this behaves in
+ # the same way as the `silent_nested` argument of the
+ # timed_activity() context manager: all but
+ # _message.unconditional_messages will be silenced.
+ #
+ @contextmanager
+ def silence(self) -> Generator[None, None, None]:
+ self._silence_scope_depth += 1
+ try:
+ yield
+ finally:
+ assert self._silence_scope_depth > 0
+ self._silence_scope_depth -= 1
+
+ # _record_message()
+ #
+ # Records the message if recording is enabled
+ #
+ # Args:
+ # message (Message): The message to record
+ #
+ def _record_message(self, message: Message) -> None:
+
+ if self.log_handle is None:
+ return
+
+ INDENT = " "
+ EMPTYTIME = "--:--:--"
+ template = "[{timecode: <8}] {type: <7}"
+
+ # If this message is associated with an element or source plugin, print the
+ # full element name of the instance.
+ element_name = ""
+ if message.element_name:
+ template += " {element_name}"
+ element_name = message.element_name
+
+ template += ": {message}"
+
+ detail = ""
+ if message.detail is not None:
+ template += "\n\n{detail}"
+ detail = message.detail.rstrip("\n")
+ detail = INDENT + INDENT.join(detail.splitlines(True))
+
+ timecode = EMPTYTIME
+ if message.message_type in (MessageType.SUCCESS, MessageType.FAIL):
+ hours, remainder = divmod(int(message.elapsed.total_seconds()), 60 ** 2)
+ minutes, seconds = divmod(remainder, 60)
+ timecode = "{0:02d}:{1:02d}:{2:02d}".format(hours, minutes, seconds)
+
+ text = template.format(
+ timecode=timecode,
+ element_name=element_name,
+ type=message.message_type.upper(),
+ message=message.message,
+ detail=detail,
+ )
+
+ # Write to the open log file
+ self.log_handle.write("{}\n".format(text))
+ self.log_handle.flush()
+
+ # _silent_messages():
+ #
+ # Returns: Whether messages are currently being silenced
+ #
+ def _silent_messages(self) -> bool:
+ return self._silence_scope_depth > 0
+
+
class Messenger:
def __init__(self) -> None:
self._state: Optional[State] = None
@@ -62,9 +212,6 @@ class Messenger:
self._locals = threading.local()
self._locals.message_handler = None
- self._locals.log_handle = None
- self._locals.log_filename = None
- self._locals.silence_scope_depth = 0
# set_message_handler()
#
@@ -75,7 +222,7 @@ class Messenger:
# handler: The handler to call on message
#
def set_message_handler(self, handler: MessageHandlerCallback) -> None:
- self._locals.message_handler = handler
+ self._locals.message_handler = _MessageHandler(handler)
# set_state()
#
@@ -97,13 +244,6 @@ class Messenger:
def set_render_status_cb(self, callback: Callable[[], None]) -> None:
self._render_status_cb = callback
- # _silent_messages():
- #
- # Returns: Whether messages are currently being silenced
- #
- def _silent_messages(self) -> bool:
- return self._locals.silence_scope_depth > 0
-
# message():
#
# Proxies a message back to the caller, this is the central
@@ -113,15 +253,7 @@ class Messenger:
# message: A Message object
#
def message(self, message: Message) -> None:
- # If we are recording messages, dump a copy into the open log file.
- self._record_message(message)
-
- # Send it off to the log handler (can be the frontend,
- # or it can be the child task which will propagate
- # to the frontend)
- assert self._locals.message_handler
-
- self._locals.message_handler(message, is_silenced=self._silent_messages())
+ self._message_handler.message(message)
# silence()
#
@@ -140,12 +272,8 @@ class Messenger:
yield
return
- self._locals.silence_scope_depth += 1
- try:
+ with self._message_handler.silence():
yield
- finally:
- assert self._locals.silence_scope_depth > 0
- self._locals.silence_scope_depth -= 1
# timed_activity()
#
@@ -275,41 +403,8 @@ class Messenger:
#
@contextmanager
def recorded_messages(self, filename: str, logdir: str) -> Generator[str, None, None]:
- # We dont allow recursing in this context manager, and
- # we also do not allow it in the main process.
- assert not hasattr(self._locals, "log_handle") or self._locals.log_handle is None
- assert not hasattr(self._locals, "log_filename") or self._locals.log_filename is None
-
- # Create the fully qualified logfile in the log directory,
- # appending the pid and .log extension at the end.
- self._locals.log_filename = os.path.join(logdir, "{}.{}.log".format(filename, os.getpid()))
- self._locals.silence_scope_depth = 0
-
- # Ensure the directory exists first
- directory = os.path.dirname(self._locals.log_filename)
- os.makedirs(directory, exist_ok=True)
-
- with open(self._locals.log_filename, "a") as logfile:
-
- # Write one last line to the log and flush it to disk
- def flush_log():
-
- # If the process currently had something happening in the I/O stack
- # then trying to reenter the I/O stack will fire a runtime error.
- #
- # So just try to flush as well as we can at SIGTERM time
- try:
- logfile.write("\n\nForcefully terminated\n")
- logfile.flush()
- except RuntimeError:
- os.fsync(logfile.fileno())
-
- self._locals.log_handle = logfile
- with _signals.terminator(flush_log):
- yield self._locals.log_filename
-
- self._locals.log_handle = None
- self._locals.log_filename = None
+ with self._message_handler.recorded_messages(filename, logdir) as file:
+ yield file
# get_log_handle()
#
@@ -319,8 +414,8 @@ class Messenger:
#
# Returns: The active logging file handle, or None
#
- def get_log_handle(self) -> str:
- return self._locals.log_handle
+ def get_log_handle(self) -> Optional[TextIO]:
+ return self._message_handler.log_handle
# get_log_filename()
#
@@ -331,7 +426,8 @@ class Messenger:
# Returns: The active logging filename, or None
#
def get_log_filename(self) -> str:
- return self._locals.log_filename
+ assert self._message_handler.log_filename is not None
+ return self._message_handler.log_filename
# timed_suspendable()
#
@@ -361,54 +457,10 @@ class Messenger:
with _signals.suspendable(stop_time, resume_time):
yield timedata
- # _record_message()
- #
- # Records the message if recording is enabled
- #
- # Args:
- # message (Message): The message to record
- #
- def _record_message(self, message: Message) -> None:
-
- if self._locals.log_handle is None:
- return
-
- INDENT = " "
- EMPTYTIME = "--:--:--"
- template = "[{timecode: <8}] {type: <7}"
-
- # If this message is associated with an element or source plugin, print the
- # full element name of the instance.
- element_name = ""
- if message.element_name:
- template += " {element_name}"
- element_name = message.element_name
-
- template += ": {message}"
-
- detail = ""
- if message.detail is not None:
- template += "\n\n{detail}"
- detail = message.detail.rstrip("\n")
- detail = INDENT + INDENT.join(detail.splitlines(True))
-
- timecode = EMPTYTIME
- if message.message_type in (MessageType.SUCCESS, MessageType.FAIL):
- hours, remainder = divmod(int(message.elapsed.total_seconds()), 60 ** 2)
- minutes, seconds = divmod(remainder, 60)
- timecode = "{0:02d}:{1:02d}:{2:02d}".format(hours, minutes, seconds)
-
- text = template.format(
- timecode=timecode,
- element_name=element_name,
- type=message.message_type.upper(),
- message=message.message,
- detail=detail,
- )
-
- # Write to the open log file
- self._locals.log_handle.write("{}\n".format(text))
- self._locals.log_handle.flush()
+ @property
+ def _message_handler(self) -> _MessageHandler:
+ assert self._locals.message_handler is not None, "No message handler has been set in this thread"
+ return self._locals.message_handler
# _render_status()
#
[buildstream] 03/11: scheduler.py: Use threads instead of processes
for jobs
Posted by tv...@apache.org.
This is an automated email from the ASF dual-hosted git repository.
tvb pushed a commit to branch bschubert/no-multiprocessing-bak
in repository https://gitbox.apache.org/repos/asf/buildstream.git
commit ad9073aac71783eefa53eccec47aba6f3b76367e
Author: Benjamin Schubert <co...@benschubert.me>
AuthorDate: Fri Jul 3 12:57:06 2020 +0000
scheduler.py: Use threads instead of processes for jobs
This changes how the scheduler works and adapts all the code that needs
adapting in order to be able to run in threads instead of in
subprocesses, which helps with Windows support, and will allow some
simplifications in the main pipeline.
---
src/buildstream/_cas/cascache.py | 67 ++++-------
src/buildstream/_cas/casdprocessmanager.py | 72 +++++++-----
src/buildstream/_context.py | 14 ---
src/buildstream/_messenger.py | 58 +++++-----
src/buildstream/_remote.py | 56 ++++-----
src/buildstream/_scheduler/_multiprocessing.py | 79 -------------
src/buildstream/_scheduler/jobs/job.py | 151 ++++++-------------------
src/buildstream/_scheduler/scheduler.py | 69 +++++------
src/buildstream/downloadablefilesource.py | 5 +
src/buildstream/source.py | 8 --
src/buildstream/testing/_fixtures.py | 1 +
tests/internals/cascache.py | 9 ++
12 files changed, 208 insertions(+), 381 deletions(-)
diff --git a/src/buildstream/_cas/cascache.py b/src/buildstream/_cas/cascache.py
index 7936121..b4e2063 100644
--- a/src/buildstream/_cas/cascache.py
+++ b/src/buildstream/_cas/cascache.py
@@ -22,11 +22,9 @@ import itertools
import os
import stat
import contextlib
-import ctypes
-import multiprocessing
-import signal
import time
from typing import Optional, List
+import threading
import grpc
@@ -34,7 +32,7 @@ from .._protos.google.rpc import code_pb2
from .._protos.build.bazel.remote.execution.v2 import remote_execution_pb2
from .._protos.build.buildgrid import local_cas_pb2
-from .. import _signals, utils
+from .. import utils
from ..types import FastEnum, SourceRef
from .._exceptions import CASCacheError
@@ -93,6 +91,7 @@ class CASCache:
self._casd_channel = self._casd_process_manager.create_channel()
self._cache_usage_monitor = _CASCacheUsageMonitor(self._casd_channel)
+ self._cache_usage_monitor.start()
# get_cas():
#
@@ -132,7 +131,8 @@ class CASCache:
#
def release_resources(self, messenger=None):
if self._cache_usage_monitor:
- self._cache_usage_monitor.release_resources()
+ self._cache_usage_monitor.stop()
+ self._cache_usage_monitor.join()
if self._casd_process_manager:
self.close_grpc_channels()
@@ -731,65 +731,42 @@ class _CASCacheUsage:
# This manages the subprocess that tracks cache usage information via
# buildbox-casd.
#
-class _CASCacheUsageMonitor:
+class _CASCacheUsageMonitor(threading.Thread):
def __init__(self, connection):
+ super().__init__()
self._connection = connection
-
- # Shared memory (64-bit signed integer) for current disk usage and quota
- self._disk_usage = multiprocessing.Value(ctypes.c_longlong, -1)
- self._disk_quota = multiprocessing.Value(ctypes.c_longlong, -1)
-
- # multiprocessing.Process will fork without exec on Unix.
- # This can't be allowed with background threads or open gRPC channels.
- assert utils._is_single_threaded() and connection.is_closed()
-
- # Block SIGINT, we don't want to kill the process when we interrupt the frontend
- # and this process if very lightweight.
- with _signals.blocked([signal.SIGINT], ignore=False):
- self._subprocess = multiprocessing.Process(target=self._subprocess_run)
- self._subprocess.start()
+ self._disk_usage = None
+ self._disk_quota = None
+ self._should_stop = False
def get_cache_usage(self):
- disk_usage = self._disk_usage.value
- disk_quota = self._disk_quota.value
-
- if disk_usage < 0:
- # Disk usage still unknown
- disk_usage = None
-
- if disk_quota <= 0:
- # No disk quota
- disk_quota = None
-
- return _CASCacheUsage(disk_usage, disk_quota)
-
- def release_resources(self):
- # Simply terminate the subprocess, no cleanup required in the subprocess
- self._subprocess.terminate()
+ # FIXME: remove this abstraction
+ return _CASCacheUsage(self._disk_usage, self._disk_quota)
- def _subprocess_run(self):
- # Reset SIGTERM in subprocess to default as no cleanup is necessary
- signal.signal(signal.SIGTERM, signal.SIG_DFL)
+ def stop(self):
+ self._should_stop = True
- disk_usage = self._disk_usage
- disk_quota = self._disk_quota
+ def run(self):
local_cas = self._connection.get_local_cas()
- while True:
+ while not self._should_stop:
try:
# Ask buildbox-casd for current value
request = local_cas_pb2.GetLocalDiskUsageRequest()
response = local_cas.GetLocalDiskUsage(request)
# Update values in shared memory
- disk_usage.value = response.size_bytes
- disk_quota.value = response.quota_bytes
+ self._disk_usage = response.size_bytes
+ self._disk_quota = response.quota_bytes
except grpc.RpcError:
# Terminate loop when buildbox-casd becomes unavailable
break
# Sleep until next refresh
- time.sleep(_CACHE_USAGE_REFRESH)
+ for _ in range(_CACHE_USAGE_REFRESH * 10):
+ if self._should_stop:
+ break
+ time.sleep(0.1)
def _grouper(iterable, n):
diff --git a/src/buildstream/_cas/casdprocessmanager.py b/src/buildstream/_cas/casdprocessmanager.py
index 637c4e0..634f696 100644
--- a/src/buildstream/_cas/casdprocessmanager.py
+++ b/src/buildstream/_cas/casdprocessmanager.py
@@ -17,6 +17,7 @@
#
import contextlib
+import threading
import os
import random
import shutil
@@ -237,33 +238,42 @@ class CASDChannel:
self._casd_cas = None
self._local_cas = None
self._casd_pid = casd_pid
+ self._shutdown_requested = False
- def _establish_connection(self):
- assert self._casd_channel is None
+ self.lock = threading.Lock()
- while not os.path.exists(self._socket_path):
- # casd is not ready yet, try again after a 10ms delay,
- # but don't wait for more than specified timeout period
- if time.time() > self._start_time + _CASD_TIMEOUT:
- raise CASCacheError("Timed out waiting for buildbox-casd to become ready")
+ def _establish_connection(self):
+ with self.lock:
+ if self._casd_channel is not None:
+ return
- # check that process is still alive
- try:
- proc = psutil.Process(self._casd_pid)
- if proc.status() == psutil.STATUS_ZOMBIE:
- proc.wait()
+ while not os.path.exists(self._socket_path):
+ # casd is not ready yet, try again after a 10ms delay,
+ # but don't wait for more than specified timeout period
+ if time.time() > self._start_time + _CASD_TIMEOUT:
+ raise CASCacheError("Timed out waiting for buildbox-casd to become ready")
- if not proc.is_running():
+ # check that process is still alive
+ try:
+ proc = psutil.Process(self._casd_pid)
+ if proc.status() == psutil.STATUS_ZOMBIE:
+ proc.wait()
+
+ if not proc.is_running():
+ if self._shutdown_requested:
+ return
+ raise CASCacheError("buildbox-casd process died before connection could be established")
+ except psutil.NoSuchProcess:
+ if self._shutdown_requested:
+ return
raise CASCacheError("buildbox-casd process died before connection could be established")
- except psutil.NoSuchProcess:
- raise CASCacheError("buildbox-casd process died before connection could be established")
- time.sleep(0.01)
+ time.sleep(0.01)
- self._casd_channel = grpc.insecure_channel(self._connection_string)
- self._bytestream = bytestream_pb2_grpc.ByteStreamStub(self._casd_channel)
- self._casd_cas = remote_execution_pb2_grpc.ContentAddressableStorageStub(self._casd_channel)
- self._local_cas = local_cas_pb2_grpc.LocalContentAddressableStorageStub(self._casd_channel)
+ self._casd_channel = grpc.insecure_channel(self._connection_string)
+ self._bytestream = bytestream_pb2_grpc.ByteStreamStub(self._casd_channel)
+ self._casd_cas = remote_execution_pb2_grpc.ContentAddressableStorageStub(self._casd_channel)
+ self._local_cas = local_cas_pb2_grpc.LocalContentAddressableStorageStub(self._casd_channel)
# get_cas():
#
@@ -279,12 +289,12 @@ class CASDChannel:
# Return LocalCAS stub for buildbox-casd channel.
#
def get_local_cas(self):
- if self._casd_channel is None:
+ if self._local_cas is None:
self._establish_connection()
return self._local_cas
def get_bytestream(self):
- if self._casd_channel is None:
+ if self._bytestream is None:
self._establish_connection()
return self._bytestream
@@ -300,10 +310,14 @@ class CASDChannel:
# Close the casd channel.
#
def close(self):
- if self.is_closed():
- return
- self._local_cas = None
- self._casd_cas = None
- self._bytestream = None
- self._casd_channel.close()
- self._casd_channel = None
+ with self.lock:
+ self._shutdown_requested = True
+
+ if self.is_closed():
+ return
+
+ self._local_cas = None
+ self._casd_cas = None
+ self._bytestream = None
+ self._casd_channel.close()
+ self._casd_channel = None
diff --git a/src/buildstream/_context.py b/src/buildstream/_context.py
index c0e92b9..ef68d95 100644
--- a/src/buildstream/_context.py
+++ b/src/buildstream/_context.py
@@ -549,17 +549,3 @@ class Context:
log_directory=self.logdir,
)
return self._cascache
-
- # prepare_fork():
- #
- # Prepare this process for fork without exec. This is a safeguard against
- # fork issues with multiple threads and gRPC connections.
- #
- def prepare_fork(self):
- # gRPC channels must be closed before fork.
- for cache in [self._cascache, self._artifactcache, self._sourcecache]:
- if cache:
- cache.close_grpc_channels()
-
- # Do not allow fork if there are background threads.
- return utils._is_single_threaded()
diff --git a/src/buildstream/_messenger.py b/src/buildstream/_messenger.py
index 3a32a24..222b05d 100644
--- a/src/buildstream/_messenger.py
+++ b/src/buildstream/_messenger.py
@@ -19,10 +19,10 @@
import os
import datetime
+import threading
from contextlib import contextmanager
from . import _signals
-from . import utils
from ._exceptions import BstError
from ._message import Message, MessageType
@@ -48,15 +48,17 @@ class _TimeData:
class Messenger:
def __init__(self):
- self._message_handler = None
- self._silence_scope_depth = 0
- self._log_handle = None
- self._log_filename = None
self._state = None
self._next_render = None # A Time object
self._active_simple_tasks = 0
self._render_status_cb = None
+ self._locals = threading.local()
+ self._locals.message_handler = None
+ self._locals.log_handle = None
+ self._locals.log_filename = None
+ self._locals.silence_scope_depth = 0
+
# set_message_handler()
#
# Sets the handler for any status messages propagated through
@@ -70,7 +72,7 @@ class Messenger:
# ) -> None
#
def set_message_handler(self, handler):
- self._message_handler = handler
+ self._locals.message_handler = handler
# set_state()
#
@@ -101,7 +103,7 @@ class Messenger:
# (bool): Whether messages are currently being silenced
#
def _silent_messages(self):
- return self._silence_scope_depth > 0
+ return self._locals.silence_scope_depth > 0
# message():
#
@@ -112,16 +114,15 @@ class Messenger:
# message: A Message object
#
def message(self, message):
-
# If we are recording messages, dump a copy into the open log file.
self._record_message(message)
# Send it off to the log handler (can be the frontend,
# or it can be the child task which will propagate
# to the frontend)
- assert self._message_handler
+ assert self._locals.message_handler
- self._message_handler(message, is_silenced=self._silent_messages())
+ self._locals.message_handler(message, is_silenced=self._silent_messages())
# silence()
#
@@ -141,12 +142,12 @@ class Messenger:
yield
return
- self._silence_scope_depth += 1
+ self._locals.silence_scope_depth += 1
try:
yield
finally:
- assert self._silence_scope_depth > 0
- self._silence_scope_depth -= 1
+ assert self._locals.silence_scope_depth > 0
+ self._locals.silence_scope_depth -= 1
# timed_activity()
#
@@ -265,22 +266,21 @@ class Messenger:
#
@contextmanager
def recorded_messages(self, filename, logdir):
-
# We dont allow recursing in this context manager, and
# we also do not allow it in the main process.
- assert self._log_handle is None
- assert self._log_filename is None
- assert not utils._is_main_process()
+ assert not hasattr(self._locals, "log_handle") or self._locals.log_handle is None
+ assert not hasattr(self._locals, "log_filename") or self._locals.log_filename is None
# Create the fully qualified logfile in the log directory,
# appending the pid and .log extension at the end.
- self._log_filename = os.path.join(logdir, "{}.{}.log".format(filename, os.getpid()))
+ self._locals.log_filename = os.path.join(logdir, "{}.{}.log".format(filename, os.getpid()))
+ self._locals.silence_scope_depth = 0
# Ensure the directory exists first
- directory = os.path.dirname(self._log_filename)
+ directory = os.path.dirname(self._locals.log_filename)
os.makedirs(directory, exist_ok=True)
- with open(self._log_filename, "a") as logfile:
+ with open(self._locals.log_filename, "a") as logfile:
# Write one last line to the log and flush it to disk
def flush_log():
@@ -295,12 +295,12 @@ class Messenger:
except RuntimeError:
os.fsync(logfile.fileno())
- self._log_handle = logfile
+ self._locals.log_handle = logfile
with _signals.terminator(flush_log):
- yield self._log_filename
+ yield self._locals.log_filename
- self._log_handle = None
- self._log_filename = None
+ self._locals.log_handle = None
+ self._locals.log_filename = None
# get_log_handle()
#
@@ -312,7 +312,7 @@ class Messenger:
# (file): The active logging file handle, or None
#
def get_log_handle(self):
- return self._log_handle
+ return self._locals.log_handle
# get_log_filename()
#
@@ -324,7 +324,7 @@ class Messenger:
# (str): The active logging filename, or None
#
def get_log_filename(self):
- return self._log_filename
+ return self._locals.log_filename
# _record_message()
#
@@ -335,7 +335,7 @@ class Messenger:
#
def _record_message(self, message):
- if self._log_handle is None:
+ if self._locals.log_handle is None:
return
INDENT = " "
@@ -372,8 +372,8 @@ class Messenger:
)
# Write to the open log file
- self._log_handle.write("{}\n".format(text))
- self._log_handle.flush()
+ self._locals.log_handle.write("{}\n".format(text))
+ self._locals.log_handle.flush()
# _render_status()
#
diff --git a/src/buildstream/_remote.py b/src/buildstream/_remote.py
index d8b8e68..6d52ff5 100644
--- a/src/buildstream/_remote.py
+++ b/src/buildstream/_remote.py
@@ -16,6 +16,7 @@
#
import os
+import threading
from collections import namedtuple
from urllib.parse import urlparse
@@ -146,41 +147,44 @@ class BaseRemote:
self.push = spec.push
self.url = spec.url
+ self._lock = threading.Lock()
+
# init():
#
# Initialize the given remote. This function must be called before
# any communication is performed, since such will otherwise fail.
#
def init(self):
- if self._initialized:
- return
-
- # Set up the communcation channel
- url = urlparse(self.spec.url)
- if url.scheme == "http":
- port = url.port or 80
- self.channel = grpc.insecure_channel("{}:{}".format(url.hostname, port))
- elif url.scheme == "https":
- port = url.port or 443
- try:
- server_cert, client_key, client_cert = _read_files(
- self.spec.server_cert, self.spec.client_key, self.spec.client_cert
+ with self._lock:
+ if self._initialized:
+ return
+
+ # Set up the communcation channel
+ url = urlparse(self.spec.url)
+ if url.scheme == "http":
+ port = url.port or 80
+ self.channel = grpc.insecure_channel("{}:{}".format(url.hostname, port))
+ elif url.scheme == "https":
+ port = url.port or 443
+ try:
+ server_cert, client_key, client_cert = _read_files(
+ self.spec.server_cert, self.spec.client_key, self.spec.client_cert
+ )
+ except FileNotFoundError as e:
+ raise RemoteError("Could not read certificates: {}".format(e)) from e
+ self.server_cert = server_cert
+ self.client_key = client_key
+ self.client_cert = client_cert
+ credentials = grpc.ssl_channel_credentials(
+ root_certificates=self.server_cert, private_key=self.client_key, certificate_chain=self.client_cert
)
- except FileNotFoundError as e:
- raise RemoteError("Could not read certificates: {}".format(e)) from e
- self.server_cert = server_cert
- self.client_key = client_key
- self.client_cert = client_cert
- credentials = grpc.ssl_channel_credentials(
- root_certificates=self.server_cert, private_key=self.client_key, certificate_chain=self.client_cert
- )
- self.channel = grpc.secure_channel("{}:{}".format(url.hostname, port), credentials)
- else:
- raise RemoteError("Unsupported URL: {}".format(self.spec.url))
+ self.channel = grpc.secure_channel("{}:{}".format(url.hostname, port), credentials)
+ else:
+ raise RemoteError("Unsupported URL: {}".format(self.spec.url))
- self._configure_protocols()
+ self._configure_protocols()
- self._initialized = True
+ self._initialized = True
def __enter__(self):
return self
diff --git a/src/buildstream/_scheduler/_multiprocessing.py b/src/buildstream/_scheduler/_multiprocessing.py
deleted file mode 100644
index 4864e14..0000000
--- a/src/buildstream/_scheduler/_multiprocessing.py
+++ /dev/null
@@ -1,79 +0,0 @@
-#
-# Copyright (C) 2019 Bloomberg Finance LP
-#
-# This program is free software; you can redistribute it and/or
-# modify it under the terms of the GNU Lesser General Public
-# License as published by the Free Software Foundation; either
-# version 2 of the License, or (at your option) any later version.
-#
-# This library is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-# Lesser General Public License for more details.
-#
-# You should have received a copy of the GNU Lesser General Public
-# License along with this library. If not, see <http://www.gnu.org/licenses/>.
-#
-
-# TLDR:
-# ALWAYS use `.AsyncioSafeProcess` when you have an asyncio event loop running and need a `multiprocessing.Process`
-#
-#
-# The upstream asyncio library doesn't play well with forking subprocesses while an event loop is running.
-#
-# The main problem that affects us is that the parent and the child will share some file handlers.
-# The most important one for us is the sig_handler_fd, which the loop uses to buffer signals received
-# by the app so that the asyncio loop can treat them afterwards.
-#
-# This sharing means that when we send a signal to the child, the sighandler in the child will write
-# it back to the parent sig_handler_fd, making the parent have to treat it too.
-# This is a problem for example when we sigterm the process. The scheduler will send sigterms to all its children,
-# which in turn will make the scheduler receive N SIGTERMs (one per child). Which in turn will send sigterms to
-# the children...
-#
-# We therefore provide a `AsyncioSafeProcess` derived from multiprocessing.Process that automatically
-# tries to cleanup the loop and never calls `waitpid` on the child process, which breaks our child watchers.
-#
-#
-# Relevant issues:
-# - Asyncio: support fork (https://bugs.python.org/issue21998)
-# - Asyncio: support multiprocessing (support fork) (https://bugs.python.org/issue22087)
-# - Signal delivered to a subprocess triggers parent's handler (https://bugs.python.org/issue31489)
-#
-#
-
-import multiprocessing
-import signal
-import sys
-from asyncio import set_event_loop_policy
-
-
-# _AsyncioSafeForkAwareProcess()
-#
-# Process class that doesn't call waitpid on its own.
-# This prevents conflicts with the asyncio child watcher.
-#
-# Also automatically close any running asyncio loop before calling
-# the actual run target
-#
-class _AsyncioSafeForkAwareProcess(multiprocessing.Process):
- # pylint: disable=attribute-defined-outside-init
- def start(self):
- self._popen = self._Popen(self)
- self._sentinel = self._popen.sentinel
-
- def run(self):
- signal.set_wakeup_fd(-1)
- set_event_loop_policy(None)
-
- super().run()
-
-
-if sys.platform != "win32":
- # Set the default event loop policy to automatically close our asyncio loop in child processes
- AsyncioSafeProcess = _AsyncioSafeForkAwareProcess
-
-else:
- # Windows doesn't support ChildWatcher that way anyways, we'll need another
- # implementation if we want it
- AsyncioSafeProcess = multiprocessing.Process
diff --git a/src/buildstream/_scheduler/jobs/job.py b/src/buildstream/_scheduler/jobs/job.py
index 7ea87dc..a4ace41 100644
--- a/src/buildstream/_scheduler/jobs/job.py
+++ b/src/buildstream/_scheduler/jobs/job.py
@@ -24,17 +24,13 @@
import asyncio
import datetime
import multiprocessing
-import os
-import signal
-import sys
import traceback
# BuildStream toplevel imports
from ..._exceptions import ImplError, BstError, set_last_task_error, SkipJob
from ..._message import Message, MessageType, unconditional_messages
from ...types import FastEnum
-from ... import _signals, utils
-from .. import _multiprocessing
+from ... import _signals
# Return code values shutdown of job handling child processes
@@ -130,7 +126,6 @@ class Job:
self._scheduler = scheduler # The scheduler
self._messenger = self._scheduler.context.messenger
self._pipe_r = None # The read end of a pipe for message passing
- self._process = None # The Process object
self._listening = False # Whether the parent is currently listening
self._suspended = False # Whether this job is currently suspended
self._max_retries = max_retries # Maximum number of automatic retries
@@ -143,6 +138,8 @@ class Job:
self._message_element_key = None # The element key for messaging
self._element = None # The Element() passed to the Job() constructor, if applicable
+ self._task = None # The task that is run
+
# set_name()
#
# Sets the name of this job
@@ -157,11 +154,13 @@ class Job:
assert not self._terminated, "Attempted to start process which was already terminated"
+ # FIXME: remove this, this is not necessary when using asyncio
self._pipe_r, pipe_w = multiprocessing.Pipe(duplex=False)
self._tries += 1
self._parent_start_listening()
+ # FIXME: remove the parent/child separation, it's not needed anymore.
child_job = self.create_child_job( # pylint: disable=assignment-from-no-return
self.action_name,
self._messenger,
@@ -173,26 +172,18 @@ class Job:
self._message_element_key,
)
- self._process = _multiprocessing.AsyncioSafeProcess(target=child_job.child_action, args=[pipe_w],)
-
- # Block signals which are handled in the main process such that
- # the child process does not inherit the parent's state, but the main
- # process will be notified of any signal after we launch the child.
- #
- with _signals.blocked([signal.SIGINT, signal.SIGTSTP, signal.SIGTERM], ignore=False):
- with asyncio.get_child_watcher() as watcher:
- self._process.start()
- # Register the process to call `_parent_child_completed` once it is done
-
- # Close the write end of the pipe in the parent
- pipe_w.close()
+ loop = asyncio.get_event_loop()
- # Here we delay the call to the next loop tick. This is in order to be running
- # in the main thread, as the callback itself must be thread safe.
- def on_completion(pid, returncode):
- asyncio.get_event_loop().call_soon(self._parent_child_completed, pid, returncode)
+ async def execute():
+ try:
+ result = await loop.run_in_executor(None, child_job.child_action, pipe_w)
+ except asyncio.CancelledError:
+ result = _ReturnCode.TERMINATED
+ except Exception: # pylint: disable=broad-except
+ result = _ReturnCode.FAIL
+ await self._parent_child_completed(result)
- watcher.add_child_handler(self._process.pid, on_completion)
+ self._task = loop.create_task(execute())
# terminate()
#
@@ -201,18 +192,14 @@ class Job:
# This will send a SIGTERM signal to the Job process.
#
def terminate(self):
-
- # First resume the job if it's suspended
- self.resume(silent=True)
-
self.message(MessageType.STATUS, "{} terminating".format(self.action_name))
# Make sure there is no garbage on the pipe
self._parent_stop_listening()
# Terminate the process using multiprocessing API pathway
- if self._process:
- self._process.terminate()
+ if self._task:
+ self._task.cancel()
self._terminated = True
@@ -226,51 +213,6 @@ class Job:
def get_terminated(self):
return self._terminated
- # kill()
- #
- # Forcefully kill the process, and any children it might have.
- #
- def kill(self):
- # Force kill
- self.message(MessageType.WARN, "{} did not terminate gracefully, killing".format(self.action_name))
- if self._process:
- utils._kill_process_tree(self._process.pid)
-
- # suspend()
- #
- # Suspend this job.
- #
- def suspend(self):
- if not self._suspended:
- self.message(MessageType.STATUS, "{} suspending".format(self.action_name))
-
- try:
- # Use SIGTSTP so that child processes may handle and propagate
- # it to processes they start that become session leaders.
- os.kill(self._process.pid, signal.SIGTSTP)
-
- # For some reason we receive exactly one suspend event for
- # every SIGTSTP we send to the child process, even though the
- # child processes are setsid(). We keep a count of these so we
- # can ignore them in our event loop suspend_event().
- self._scheduler.internal_stops += 1
- self._suspended = True
- except ProcessLookupError:
- # ignore, process has already exited
- pass
-
- # resume()
- #
- # Resume this suspended job.
- #
- def resume(self, silent=False):
- if self._suspended:
- if not silent and not self._scheduler.terminated:
- self.message(MessageType.STATUS, "{} resuming".format(self.action_name))
-
- os.kill(self._process.pid, signal.SIGCONT)
- self._suspended = False
-
# set_message_element_name()
#
# This is called by Job subclasses to set the plugin instance element
@@ -397,10 +339,9 @@ class Job:
# Called in the main process courtesy of asyncio's ChildWatcher.add_child_handler()
#
# Args:
- # pid (int): The PID of the child which completed
# returncode (int): The return code of the child process
#
- def _parent_child_completed(self, pid, returncode):
+ async def _parent_child_completed(self, returncode):
self._parent_shutdown()
try:
@@ -431,16 +372,16 @@ class Job:
status = JobStatus.FAIL
elif returncode == _ReturnCode.TERMINATED:
if self._terminated:
- self.message(MessageType.INFO, "Process was terminated")
+ self.message(MessageType.INFO, "Job terminated")
else:
- self.message(MessageType.ERROR, "Process was terminated unexpectedly")
+ self.message(MessageType.ERROR, "Job was terminated unexpectedly")
status = JobStatus.FAIL
elif returncode == _ReturnCode.KILLED:
if self._terminated:
- self.message(MessageType.INFO, "Process was killed")
+ self.message(MessageType.INFO, "Job was killed")
else:
- self.message(MessageType.ERROR, "Process was killed unexpectedly")
+ self.message(MessageType.ERROR, "Job was killed unexpectedly")
status = JobStatus.FAIL
else:
@@ -451,7 +392,7 @@ class Job:
# Force the deletion of the pipe and process objects to try and clean up FDs
self._pipe_r.close()
- self._pipe_r = self._process = None
+ self._pipe_r = self._task = None
# _parent_process_envelope()
#
@@ -655,19 +596,6 @@ class ChildJob:
# pipe_w (multiprocessing.connection.Connection): The message pipe for IPC
#
def child_action(self, pipe_w):
-
- # This avoids some SIGTSTP signals from grandchildren
- # getting propagated up to the master process
- os.setsid()
-
- # First set back to the default signal handlers for the signals
- # we handle, and then clear their blocked state.
- #
- signal_list = [signal.SIGTSTP, signal.SIGTERM]
- for sig in signal_list:
- signal.signal(sig, signal.SIG_DFL)
- signal.pthread_sigmask(signal.SIG_UNBLOCK, signal_list)
-
# Assign the pipe we passed across the process boundaries
#
# Set the global message handler in this child
@@ -687,16 +615,11 @@ class ChildJob:
nonlocal starttime
starttime += datetime.datetime.now() - stopped_time
- # Graciously handle sigterms.
- def handle_sigterm():
- self._child_shutdown(_ReturnCode.TERMINATED)
-
# Time, log and and run the action function
#
- with _signals.terminator(handle_sigterm), _signals.suspendable(
- stop_time, resume_time
- ), self._messenger.recorded_messages(self._logfile, self._logdir) as filename:
-
+ with _signals.suspendable(stop_time, resume_time), self._messenger.recorded_messages(
+ self._logfile, self._logdir
+ ) as filename:
self.message(MessageType.START, self.action_name, logfile=filename)
try:
@@ -707,7 +630,7 @@ class ChildJob:
self.message(MessageType.SKIPPED, str(e), elapsed=elapsed, logfile=filename)
# Alert parent of skip by return code
- self._child_shutdown(_ReturnCode.SKIPPED)
+ return _ReturnCode.SKIPPED
except BstError as e:
elapsed = datetime.datetime.now() - starttime
retry_flag = e.temporary
@@ -731,7 +654,7 @@ class ChildJob:
# Set return code based on whether or not the error was temporary.
#
- self._child_shutdown(_ReturnCode.FAIL if retry_flag else _ReturnCode.PERM_FAIL)
+ return _ReturnCode.FAIL if retry_flag else _ReturnCode.PERM_FAIL
except Exception: # pylint: disable=broad-except
@@ -744,7 +667,7 @@ class ChildJob:
self.message(MessageType.BUG, self.action_name, elapsed=elapsed, detail=detail, logfile=filename)
# Unhandled exceptions should permenantly fail
- self._child_shutdown(_ReturnCode.PERM_FAIL)
+ return _ReturnCode.PERM_FAIL
else:
# No exception occurred in the action
@@ -757,7 +680,9 @@ class ChildJob:
# Shutdown needs to stay outside of the above context manager,
# make sure we dont try to handle SIGTERM while the process
# is already busy in sys.exit()
- self._child_shutdown(_ReturnCode.OK)
+ return _ReturnCode.OK
+ finally:
+ self._pipe_w.close()
#######################################################
# Local Private Methods #
@@ -809,18 +734,6 @@ class ChildJob:
if result is not None:
self._send_message(_MessageType.RESULT, result)
- # _child_shutdown()
- #
- # Shuts down the child process by cleaning up and exiting the process
- #
- # Args:
- # exit_code (_ReturnCode): The exit code to exit with
- #
- def _child_shutdown(self, exit_code):
- self._pipe_w.close()
- assert isinstance(exit_code, _ReturnCode)
- sys.exit(exit_code.value)
-
# _child_message_handler()
#
# A Context delegate for handling messages, this replaces the
diff --git a/src/buildstream/_scheduler/scheduler.py b/src/buildstream/_scheduler/scheduler.py
index 3e6bf1f..7380f07 100644
--- a/src/buildstream/_scheduler/scheduler.py
+++ b/src/buildstream/_scheduler/scheduler.py
@@ -20,12 +20,14 @@
# Jürg Billeter <ju...@codethink.co.uk>
# System imports
+import functools
import os
import asyncio
from itertools import chain
import signal
import datetime
import sys
+from concurrent.futures import ThreadPoolExecutor
# Local imports
from .resources import Resources
@@ -34,9 +36,7 @@ from ..types import FastEnum
from .._profile import Topics, PROFILER
from .._message import Message, MessageType
from ..plugin import Plugin
-
-
-_MAX_TIMEOUT_TO_KILL_CHILDREN = 20 # in seconds
+from .. import _signals
# A decent return code for Scheduler.run()
@@ -46,6 +46,23 @@ class SchedStatus(FastEnum):
TERMINATED = 1
+def reset_signals_on_exit(func):
+ @functools.wraps(func)
+ def wrapper(*args, **kwargs):
+ orig_sigint = signal.getsignal(signal.SIGINT)
+ orig_sigterm = signal.getsignal(signal.SIGTERM)
+ orig_sigtstp = signal.getsignal(signal.SIGTSTP)
+
+ try:
+ return func(*args, **kwargs)
+ finally:
+ signal.signal(signal.SIGINT, orig_sigint)
+ signal.signal(signal.SIGTERM, orig_sigterm)
+ signal.signal(signal.SIGTSTP, orig_sigtstp)
+
+ return wrapper
+
+
# Scheduler()
#
# The scheduler operates on a list queues, each of which is meant to accomplish
@@ -79,7 +96,6 @@ class Scheduler:
# These are shared with the Job, but should probably be removed or made private in some way.
self.loop = None # Shared for Job access to observe the message queue
- self.internal_stops = 0 # Amount of SIGSTP signals we've introduced, this is shared with job.py
#
# Private members
@@ -113,6 +129,7 @@ class Scheduler:
# elements have been processed by each queue or when
# an error arises
#
+ @reset_signals_on_exit
def run(self, queues, casd_process_manager):
# Hold on to the queues to process
@@ -149,10 +166,14 @@ class Scheduler:
# Start the profiler
with PROFILER.profile(Topics.SCHEDULER, "_".join(queue.action_name for queue in self.queues)):
- # Run the queues
- self._sched()
- self.loop.run_forever()
- self.loop.close()
+ # FIXME: this should be done in a cleaner way
+ with _signals.suspendable(lambda: None, lambda: None), _signals.terminator(lambda: None):
+ with ThreadPoolExecutor(max_workers=sum(self.resources._max_resources.values())) as pool:
+ self.loop.set_default_executor(pool)
+ # Run the queues
+ self._sched()
+ self.loop.run_forever()
+ self.loop.close()
# Stop watching casd
_watcher.remove_child_handler(self._casd_process.pid)
@@ -348,13 +369,6 @@ class Scheduler:
# If that happens, do another round.
process_queues = any(q.dequeue_ready() for q in self.queues)
- # Make sure fork is allowed before starting jobs
- if not self.context.prepare_fork():
- message = Message(MessageType.BUG, "Fork is not allowed", detail="Background threads are active")
- self.context.messenger.message(message)
- self.terminate()
- return
-
# Start the jobs
#
for job in ready:
@@ -412,9 +426,9 @@ class Scheduler:
if not self.suspended:
self._suspendtime = datetime.datetime.now()
self.suspended = True
- # Notify that we're suspended
- for job in self._active_jobs:
- job.suspend()
+
+ for suspender in reversed(_signals.suspendable_stack):
+ suspender.suspend()
# _resume_jobs()
#
@@ -422,8 +436,9 @@ class Scheduler:
#
def _resume_jobs(self):
if self.suspended:
- for job in self._active_jobs:
- job.resume()
+ for suspender in _signals.suspendable_stack:
+ suspender.resume()
+
self.suspended = False
# Notify that we're unsuspended
self._state.offset_start_time(datetime.datetime.now() - self._suspendtime)
@@ -455,12 +470,6 @@ class Scheduler:
# A loop registered event callback for SIGTSTP
#
def _suspend_event(self):
-
- # Ignore the feedback signals from Job.suspend()
- if self.internal_stops:
- self.internal_stops -= 1
- return
-
# No need to care if jobs were suspended or not, we _only_ handle this
# while we know jobs are not suspended.
self._suspend_jobs()
@@ -482,12 +491,8 @@ class Scheduler:
self.loop.remove_signal_handler(signal.SIGTERM)
def _terminate_jobs_real(self):
- def kill_jobs():
- for job_ in self._active_jobs:
- job_.kill()
-
- # Schedule all jobs to be killed if they have not exited after timeout
- self.loop.call_later(_MAX_TIMEOUT_TO_KILL_CHILDREN, kill_jobs)
+ for terminator in _signals.terminator_stack.copy():
+ terminator()
for job in self._active_jobs:
job.terminate()
diff --git a/src/buildstream/downloadablefilesource.py b/src/buildstream/downloadablefilesource.py
index 7c2da1c..b9ca919 100644
--- a/src/buildstream/downloadablefilesource.py
+++ b/src/buildstream/downloadablefilesource.py
@@ -259,6 +259,11 @@ class DownloadableFileSource(Source):
return self.__default_mirror_file
+ @classmethod
+ def _reset_url_opener(cls):
+ # Needed for tests, in order to cleanup the `netrc` configuration.
+ cls.__urlopener = None
+
def __get_urlopener(self):
if not DownloadableFileSource.__urlopener:
try:
diff --git a/src/buildstream/source.py b/src/buildstream/source.py
index f15d5a6..8431590 100644
--- a/src/buildstream/source.py
+++ b/src/buildstream/source.py
@@ -990,19 +990,11 @@ class Source(Plugin):
clean = node.strip_node_info()
to_modify = node.strip_node_info()
- current_ref = self.get_ref() # pylint: disable=assignment-from-no-return
-
# Set the ref regardless of whether it changed, the
# TrackQueue() will want to update a specific node with
# the ref, regardless of whether the original has changed.
self.set_ref(new_ref, to_modify)
- if current_ref == new_ref or not save:
- # Note: We do not look for and propagate changes at this point
- # which might result in desync depending if something changes about
- # tracking in the future. For now, this is quite safe.
- return False
-
actions = {}
for k, v in clean.items():
if k not in to_modify:
diff --git a/src/buildstream/testing/_fixtures.py b/src/buildstream/testing/_fixtures.py
index 5d1c1d2..520f685 100644
--- a/src/buildstream/testing/_fixtures.py
+++ b/src/buildstream/testing/_fixtures.py
@@ -42,3 +42,4 @@ def thread_check(default_thread_number):
@pytest.fixture(autouse=True)
def reset_global_node_state():
node._reset_global_state()
+ DownloadableFileSource._reset_url_opener()
diff --git a/tests/internals/cascache.py b/tests/internals/cascache.py
index 043531c..e27e409 100644
--- a/tests/internals/cascache.py
+++ b/tests/internals/cascache.py
@@ -3,6 +3,7 @@ import time
from unittest.mock import MagicMock
from buildstream._cas.cascache import CASCache
+from buildstream._cas import casdprocessmanager
from buildstream._message import MessageType
from buildstream._messenger import Messenger
@@ -31,6 +32,10 @@ def test_report_when_cascache_exits_not_cleanly(tmp_path, monkeypatch):
dummy_buildbox_casd.write_text("#!/usr/bin/env sh\nwhile :\ndo\nsleep 60\ndone")
dummy_buildbox_casd.chmod(0o777)
monkeypatch.setenv("PATH", str(tmp_path), prepend=os.pathsep)
+ # FIXME: this is a hack, we should instead have a socket be created nicely
+ # on the fake casd script. This whole test suite probably would
+ # need some cleanup
+ monkeypatch.setattr(casdprocessmanager, "_CASD_TIMEOUT", 0.1)
messenger = MagicMock(spec_set=Messenger)
cache = CASCache(str(tmp_path.joinpath("casd")), casd=True, log_directory=str(tmp_path.joinpath("logs")))
@@ -50,6 +55,10 @@ def test_report_when_cascache_is_forcefully_killed(tmp_path, monkeypatch):
dummy_buildbox_casd.write_text("#!/usr/bin/env sh\ntrap 'echo hello' TERM\nwhile :\ndo\nsleep 60\ndone")
dummy_buildbox_casd.chmod(0o777)
monkeypatch.setenv("PATH", str(tmp_path), prepend=os.pathsep)
+ # FIXME: this is a hack, we should instead have a socket be created nicely
+ # on the fake casd script. This whole test suite probably would
+ # need some cleanup
+ monkeypatch.setattr(casdprocessmanager, "_CASD_TIMEOUT", 0.1)
messenger = MagicMock(spec_set=Messenger)
cache = CASCache(str(tmp_path.joinpath("casd")), casd=True, log_directory=str(tmp_path.joinpath("logs")))
[buildstream] 06/11: job.py: Remove the ability to send back child
data
Posted by tv...@apache.org.
This is an automated email from the ASF dual-hosted git repository.
tvb pushed a commit to branch bschubert/no-multiprocessing-bak
in repository https://gitbox.apache.org/repos/asf/buildstream.git
commit aaf2fcda89686f58e01e94096515890a3f077664
Author: Benjamin Schubert <co...@benschubert.me>
AuthorDate: Tue Jul 7 17:58:50 2020 +0100
job.py: Remove the ability to send back child data
We only use this for workspace information that we can now get directly
since we run in the same process
---
src/buildstream/_scheduler/jobs/elementjob.py | 9 ---------
src/buildstream/_scheduler/jobs/job.py | 22 ----------------------
src/buildstream/_scheduler/queues/queue.py | 10 +++++-----
3 files changed, 5 insertions(+), 36 deletions(-)
diff --git a/src/buildstream/_scheduler/jobs/elementjob.py b/src/buildstream/_scheduler/jobs/elementjob.py
index 6e035be..61dda50 100644
--- a/src/buildstream/_scheduler/jobs/elementjob.py
+++ b/src/buildstream/_scheduler/jobs/elementjob.py
@@ -101,12 +101,3 @@ class ChildElementJob(ChildJob):
# Run the action
return self._action_cb(self._element)
-
- def child_process_data(self):
- data = {}
-
- workspace = self._element._get_workspace()
- if workspace is not None:
- data["workspace"] = workspace.to_dict()
-
- return data
diff --git a/src/buildstream/_scheduler/jobs/job.py b/src/buildstream/_scheduler/jobs/job.py
index 29f2e36..f331d3f 100644
--- a/src/buildstream/_scheduler/jobs/job.py
+++ b/src/buildstream/_scheduler/jobs/job.py
@@ -70,7 +70,6 @@ class _MessageType(FastEnum):
LOG_MESSAGE = 1
ERROR = 2
RESULT = 3
- CHILD_DATA = 4
# Job()
@@ -116,7 +115,6 @@ class Job:
#
self.name = None # The name of the job, set by the job's subclass
self.action_name = action_name # The action name for the Queue
- self.child_data = None # Data to be sent to the main process
#
# Private members
@@ -403,9 +401,6 @@ class Job:
elif envelope.message_type is _MessageType.RESULT:
assert self._result is None
self._result = envelope.message
- elif envelope.message_type is _MessageType.CHILD_DATA:
- # If we retry a job, we assign a new value to this
- self.child_data = envelope.message
else:
assert False, "Unhandled message type '{}': {}".format(envelope.message_type, envelope.message)
@@ -535,20 +530,6 @@ class ChildJob:
def child_process(self):
raise ImplError("ChildJob '{kind}' does not implement child_process()".format(kind=type(self).__name__))
- # child_process_data()
- #
- # Abstract method to retrieve additional data that should be
- # returned to the parent process. Note that the job result is
- # retrieved independently.
- #
- # Values can later be retrieved in Job.child_data.
- #
- # Returns:
- # (dict) A dict containing values to be reported to the main process
- #
- def child_process_data(self):
- return {}
-
# child_action()
#
# Perform the action in the child process, this calls the action_cb.
@@ -596,8 +577,6 @@ class ChildJob:
MessageType.FAIL, str(e), elapsed=elapsed, detail=e.detail, logfile=filename, sandbox=e.sandbox
)
- self._send_message(_MessageType.CHILD_DATA, self.child_process_data())
-
# Report the exception to the parent (for internal testing purposes)
self._child_send_error(e)
@@ -620,7 +599,6 @@ class ChildJob:
else:
# No exception occurred in the action
- self._send_message(_MessageType.CHILD_DATA, self.child_process_data())
self._child_send_result(result)
elapsed = datetime.datetime.now() - timeinfo.start_time
diff --git a/src/buildstream/_scheduler/queues/queue.py b/src/buildstream/_scheduler/queues/queue.py
index 9e444b3..96a7016 100644
--- a/src/buildstream/_scheduler/queues/queue.py
+++ b/src/buildstream/_scheduler/queues/queue.py
@@ -268,16 +268,16 @@ class Queue:
# job (Job): The job which completed
#
def _update_workspaces(self, element, job):
- workspace_dict = None
- if job.child_data:
- workspace_dict = job.child_data.get("workspace", None)
+ # FIXME: This should be done only for build jobs and not by proding
+ # the element, but as an explicit return value from the job
+ workspace = element._get_workspace()
# Handle any workspace modifications now
#
- if workspace_dict:
+ if workspace:
context = element._get_context()
workspaces = context.get_workspaces()
- if workspaces.update_workspace(element._get_full_name(), workspace_dict):
+ if workspaces.update_workspace(element._get_full_name(), workspace.to_dict()):
try:
workspaces.save_config()
except BstError as e:
[buildstream] 01/11: _signals.py: allow calling signal handler from
non-main threads
Posted by tv...@apache.org.
This is an automated email from the ASF dual-hosted git repository.
tvb pushed a commit to branch bschubert/no-multiprocessing-bak
in repository https://gitbox.apache.org/repos/asf/buildstream.git
commit 090b02712196b8300357e4419925c968d1d020be
Author: Benjamin Schubert <co...@benschubert.me>
AuthorDate: Wed Jun 17 20:57:37 2020 +0000
_signals.py: allow calling signal handler from non-main threads
This modifies the signal terminator so that it can be called from any
thread.
This checks that either:
- The signal handler is already in place
- Or the caller is in the main thread, allowing to set the signal
handler.
This also removes the exact callback that was added instead of removing
the last one, and fixes the `suspend_handler` to do the same.
This is required, as we don't know which interleaving of calls will be
done, and we can't guarantee that the last one is the right one to
remove
---
src/buildstream/_cas/casserver.py | 7 ++++++-
src/buildstream/_signals.py | 13 ++++++-------
2 files changed, 12 insertions(+), 8 deletions(-)
diff --git a/src/buildstream/_cas/casserver.py b/src/buildstream/_cas/casserver.py
index 71d7d90..a97128e 100644
--- a/src/buildstream/_cas/casserver.py
+++ b/src/buildstream/_cas/casserver.py
@@ -29,6 +29,7 @@ import grpc
from google.protobuf.message import DecodeError
import click
+from .. import _signals
from .._protos.build.bazel.remote.execution.v2 import (
remote_execution_pb2,
remote_execution_pb2_grpc,
@@ -149,7 +150,11 @@ def create_server(repo, *, enable_push, quota, index_only, log_level=LogLevel.Le
_BuildStreamCapabilitiesServicer(artifact_capabilities, source_capabilities), server
)
- yield server
+ # Ensure we have the signal handler set for SIGTERM
+ # This allows threads from GRPC to call our methods that do register
+ # handlers at exit.
+ with _signals.terminator(lambda: None):
+ yield server
finally:
casd_channel.close()
diff --git a/src/buildstream/_signals.py b/src/buildstream/_signals.py
index 03b55b0..1edd445 100644
--- a/src/buildstream/_signals.py
+++ b/src/buildstream/_signals.py
@@ -80,13 +80,10 @@ def terminator_handler(signal_, frame):
def terminator(terminate_func):
global terminator_stack # pylint: disable=global-statement
- # Signal handling only works in the main thread
- if threading.current_thread() != threading.main_thread():
- yield
- return
-
outermost = bool(not terminator_stack)
+ assert threading.current_thread() == threading.main_thread() or not outermost
+
terminator_stack.append(terminate_func)
if outermost:
original_handler = signal.signal(signal.SIGTERM, terminator_handler)
@@ -96,7 +93,7 @@ def terminator(terminate_func):
finally:
if outermost:
signal.signal(signal.SIGTERM, original_handler)
- terminator_stack.pop()
+ terminator_stack.remove(terminate_func)
# Just a simple object for holding on to two callbacks
@@ -146,6 +143,8 @@ def suspendable(suspend_callback, resume_callback):
global suspendable_stack # pylint: disable=global-statement
outermost = bool(not suspendable_stack)
+ assert threading.current_thread() == threading.main_thread() or not outermost
+
suspender = Suspender(suspend_callback, resume_callback)
suspendable_stack.append(suspender)
@@ -158,7 +157,7 @@ def suspendable(suspend_callback, resume_callback):
if outermost:
signal.signal(signal.SIGTSTP, original_stop)
- suspendable_stack.pop()
+ suspendable_stack.remove(suspender)
# blocked()