Message364580
When a thread gets a signal, SIGNAL_PENDING_SIGNALS() sets signals_pending to 1 and eval_breaker to 1. In this case, _PyEval_EvalFrameDefault() calls handle_signals(), but since it's not the main thread, it does nothing and signals_pending value remains 1. Moreover, eval_breaker value remains 1 which means that the following code will be called before executing *each* bytecode instruction.
if (_Py_atomic_load_relaxed(eval_breaker)) {
(...)
opcode = _Py_OPCODE(*next_instr);
if (opcode == SETUP_FINALLY || ...) {
...
}
if (_Py_atomic_load_relaxed(&ceval->signals_pending)) {
if (handle_signals(tstate) != 0) {
goto error;
}
}
if (_Py_atomic_load_relaxed(&ceval->pending.calls_to_do)) {
...
}
if (_Py_atomic_load_relaxed(&ceval->gil_drop_request)) {
...
}
if (tstate->async_exc != NULL) {
...
}
}
This is inefficient.
I'm working on a PR modifying SIGNAL_PENDING_SIGNALS() to not set eval_breaker to 1 if the current thread is not the main thread. |
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Date |
User |
Action |
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2020-03-19 00:57:19 | vstinner | set | recipients:
+ vstinner |
2020-03-19 00:57:19 | vstinner | set | messageid: <1584579439.15.0.43767534151.issue40010@roundup.psfhosted.org> |
2020-03-19 00:57:19 | vstinner | link | issue40010 messages |
2020-03-19 00:57:18 | vstinner | create | |
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