Description

vstinner

opened on Apr 8, 2020

Issue body actions

BPO	40231
Nosy	@vstinner, @ericsnowcurrently

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2020-04-08.21:33:25.205>
labels = ['expert-subinterpreters', '3.9']
title = '[subinterpreters] Fix pending calls in subinterpreters'
updated_at = <Date 2020-05-15.00:39:53.889>
user = 'https://github.com/vstinner'

bugs.python.org fields:

activity = <Date 2020-05-15.00:39:53.889>
actor = 'vstinner'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Subinterpreters']
creation = <Date 2020-04-08.21:33:25.205>
creator = 'vstinner'
dependencies = []
files = []
hgrepos = []
issue_num = 40231
keywords = []
message_count = 2.0
messages = ['366010', '366014']
nosy_count = 2.0
nosy_names = ['vstinner', 'eric.snow']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = None
url = 'https://bugs.python.org/issue40231'
versions = ['Python 3.9']

Activity

1. vstinner commented on Apr 8, 2020

   

   vstinner

   on Apr 8, 2020

   MemberAuthor

   More actions

   Currently, _Py_ThreadCanHandlePendingCalls() only returns true if the current thread is the Python "main thread" (_PyRuntime.main_thread).

   _PyRuntime.main_thread is initialized by _PyRuntime_Initialize().

   The problem is that a subinterpreter can run a separated thread which may not be the "main thread".

   As a consequence, a subinterpreter will not run schedulded pending calls, or it will run them later than it could.

   I modified COMPUTE_EVAL_BREAKER() of ceval.c in bpo-40010: now if tstate->interp->ceval.pending.calls_to_do is true, tstate->interp->ceval.eval_breaker is only set to 1 if _Py_ThreadCanHandlePendingCalls() is true.

   One option would be to allow any thread to run "pending calls".

   Another option is to have one "main thread" per interpreter, rather than having a single "main thread" for all interpreters.

   I made pending calls per-interpreter in bpo-39984.

   In Python 3.7, main_thread variable came from _PyRutimeState.ceval.pending.main_thread. It was moved into _PyRuntimeState by this change:

   commit 5be45a6
   Author: Eric Snow <[email protected]>
   Date: Fri Mar 8 22:47:07 2019 -0700

   bpo-33608: Minor cleanup related to pending calls. (gh-12247)
   

   --

   _Py_ThreadCanHandleSignals() doesn't have to change: it must only return true for the main thread of the main interpreter. Currently, it's implemented as:

   static inline int
   _Py_ThreadCanHandleSignals(PyThreadState *tstate)
   {
       return (_Py_IsMainThread() && _Py_IsMainInterpreter(tstate));
   }
2. vstinner

   added

   interpreter-core(Objects, Python, Grammar, and Parser dirs)(Objects, Python, Grammar, and Parser dirs)

   3.9 (EOL)end of lifeend of life

   on Apr 8, 2020
3. vstinner commented on Apr 8, 2020

   

   vstinner

   on Apr 8, 2020

   MemberAuthor

   More actions

   I modified _PyEval_AddPendingCall() to accept interp rather than tstate to fix bpo-40082:

   New changeset b54a99d by Victor Stinner in branch 'master':
   bpo-40082: trip_signal() uses the main interpreter (GH-19441)
   b54a99d
4. vstinner

   added

   topic-subinterpreters

   and removed

   interpreter-core(Objects, Python, Grammar, and Parser dirs)(Objects, Python, Grammar, and Parser dirs)

   on May 15, 2020
5. vstinner

   changed the title [-]Fix pending calls in subinterpreters[/-] [+][subinterpreters] Fix pending calls in subinterpreters[/+] on May 15, 2020
6. vstinner

   added

   topic-subinterpreters

   and removed

   interpreter-core(Objects, Python, Grammar, and Parser dirs)(Objects, Python, Grammar, and Parser dirs)

   on May 15, 2020
7. vstinner

   changed the title [-]Fix pending calls in subinterpreters[/-] [+][subinterpreters] Fix pending calls in subinterpreters[/+] on May 15, 2020
8. ezio-melotti

   transferred this issue fromon Apr 10, 2022
9. ezio-melotti

   added this to Subinterpreterson Apr 15, 2022
10. ezio-melotti

    moved this to Todo in Subinterpreterson Apr 15, 2022
11. vstinner commented on Nov 3, 2022

    

    vstinner

    on Nov 3, 2022

    MemberAuthor

    More actions

    I don't have the bandwidth to work on this issue, so I just close it.
12. vstinner

    closed this as completedon Nov 3, 2022
13. Repository owner moved this from Todo to Done in Subinterpreterson Nov 3, 2022

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