From d83168854e19d0381fa57db25fca6c622917624f Mon Sep 17 00:00:00 2001 From: Victor Stinner Date: Fri, 20 Mar 2020 14:50:35 +0100 Subject: bpo-40010: Optimize pending calls in multithreaded applications (GH-19091) If a thread different than the main thread schedules a pending call (Py_AddPendingCall()), the bytecode evaluation loop is no longer interrupted at each bytecode instruction to check for pending calls which cannot be executed. Only the main thread can execute pending calls. Previously, the bytecode evaluation loop was interrupted at each instruction until the main thread executes pending calls. * Add _Py_ThreadCanHandlePendingCalls() function. * SIGNAL_PENDING_CALLS() now only sets eval_breaker to 1 if the current thread can execute pending calls. Only the main thread can execute pending calls. --- Python/ceval.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'Python') diff --git a/Python/ceval.c b/Python/ceval.c index 86aa225389..c80ee4b463 100644 --- a/Python/ceval.c +++ b/Python/ceval.c @@ -149,7 +149,8 @@ COMPUTE_EVAL_BREAKER(PyThreadState *tstate, _Py_atomic_load_relaxed(&ceval->gil_drop_request) | (_Py_atomic_load_relaxed(&ceval->signals_pending) && _Py_ThreadCanHandleSignals(tstate)) - | _Py_atomic_load_relaxed(&ceval2->pending.calls_to_do) + | (_Py_atomic_load_relaxed(&ceval2->pending.calls_to_do) + && _Py_ThreadCanHandlePendingCalls()) | ceval2->pending.async_exc); } @@ -180,9 +181,10 @@ static inline void SIGNAL_PENDING_CALLS(PyThreadState *tstate) { assert(is_tstate_valid(tstate)); + struct _ceval_runtime_state *ceval = &tstate->interp->runtime->ceval; struct _ceval_state *ceval2 = &tstate->interp->ceval; _Py_atomic_store_relaxed(&ceval2->pending.calls_to_do, 1); - _Py_atomic_store_relaxed(&ceval2->eval_breaker, 1); + COMPUTE_EVAL_BREAKER(tstate, ceval, ceval2); } @@ -606,8 +608,8 @@ handle_signals(PyThreadState *tstate) static int make_pending_calls(PyThreadState *tstate) { - /* only service pending calls on main thread */ - if (!_Py_IsMainThread()) { + /* only execute pending calls on main thread */ + if (!_Py_ThreadCanHandlePendingCalls()) { return 0; } -- cgit v1.2.1