diff options
Diffstat (limited to 'Modules/signalmodule.c')
| -rw-r--r-- | Modules/signalmodule.c | 31 |
1 files changed, 26 insertions, 5 deletions
diff --git a/Modules/signalmodule.c b/Modules/signalmodule.c index a729604..9d223d5 100644 --- a/Modules/signalmodule.c +++ b/Modules/signalmodule.c @@ -75,7 +75,8 @@ static struct { PyObject *func; } Handlers[NSIG]; -static int is_tripped = 0; /* Speed up sigcheck() when none tripped */ +/* Speed up sigcheck() when none tripped */ +static volatile sig_atomic_t is_tripped = 0; static PyObject *DefaultHandler; static PyObject *IgnoreHandler; @@ -122,8 +123,10 @@ signal_handler(int sig_num) /* See NOTES section above */ if (getpid() == main_pid) { #endif - is_tripped++; Handlers[sig_num].tripped = 1; + /* Set is_tripped after setting .tripped, as it gets + cleared in PyErr_CheckSignals() before .tripped. */ + is_tripped = 1; Py_AddPendingCall(checksignals_witharg, NULL); #ifdef WITH_THREAD } @@ -597,13 +600,31 @@ PyErr_CheckSignals(void) if (!is_tripped) return 0; + #ifdef WITH_THREAD if (PyThread_get_thread_ident() != main_thread) return 0; #endif + + /* + * The is_stripped variable is meant to speed up the calls to + * PyErr_CheckSignals (both directly or via pending calls) when no + * signal has arrived. This variable is set to 1 when a signal arrives + * and it is set to 0 here, when we know some signals arrived. This way + * we can run the registered handlers with no signals blocked. + * + * NOTE: with this approach we can have a situation where is_tripped is + * 1 but we have no more signals to handle (Handlers[i].tripped + * is 0 for every signal i). This won't do us any harm (except + * we're gonna spent some cycles for nothing). This happens when + * we receive a signal i after we zero is_tripped and before we + * check Handlers[i].tripped. + */ + is_tripped = 0; + if (!(f = (PyObject *)PyEval_GetFrame())) f = Py_None; - + for (i = 1; i < NSIG; i++) { if (Handlers[i].tripped) { PyObject *result = NULL; @@ -621,7 +642,7 @@ PyErr_CheckSignals(void) Py_DECREF(result); } } - is_tripped = 0; + return 0; } @@ -632,7 +653,7 @@ PyErr_CheckSignals(void) void PyErr_SetInterrupt(void) { - is_tripped++; + is_tripped = 1; Handlers[SIGINT].tripped = 1; Py_AddPendingCall((int (*)(void *))PyErr_CheckSignals, NULL); } |