/*
* Once dication has happened this fires, for better or worse
*/
static void voice_callback(DictationSession *session, DictationSessionStatus status, char *transcription, void *context) {
// If for worse then this is where we go
if (status != DictationSessionStatusSuccess) {
LOG_WARN("dictation failed");
dictation_session_stop(session);
voice_system_active = false;
respond_with_vibe(false);
show_notice(status == DictationSessionStatusFailureTranscriptionRejected ? RESOURCE_ID_NOTICE_VOICE_STOPPED : RESOURCE_ID_NOTICE_VOICE_FAILED);
return;
}
// If we were lucky then we try to match the transcription to a menu item
dictation_session_stop(session);
LOG_INFO("dictation got %s", transcription);
bool vibe;
VoiceSelectAction action = determine_action(transcription, &vibe);
// Allow comms and notices
voice_system_active = false;
if (action != NULL) {
// If we get a match then fire the action
if (vibe)
respond_with_vibe(true);
action();
} else {
// Feedback we didn't find anything
respond_with_vibe(false);
show_notice_with_message(RESOURCE_ID_VOICE_DIDNT_UNDERSTAND, transcription);
}
}
// The stack-unwinding loop.
static inline void unwind_loop(ExcInfo* exc_data) {
// NB. https://monoinfinito.wordpress.com/series/exception-handling-in-c/ is a very useful resource
// as are http://www.airs.com/blog/archives/460 and http://www.airs.com/blog/archives/464
unw_cursor_t cursor;
unw_context_t uc; // exists only to initialize cursor
#ifndef NDEBUG
// poison stack memory. have had problems with these structures being insufficiently initialized.
memset(&uc, 0xef, sizeof uc);
memset(&cursor, 0xef, sizeof cursor);
#endif
unw_getcontext(&uc);
unw_init_local(&cursor, &uc);
auto unwind_session = getActivePythonUnwindSession();
while (unw_step(&cursor) > 0) {
unw_proc_info_t pip;
static StatCounter frames_unwound("num_frames_unwound_cxx");
frames_unwound.log();
// NB. unw_get_proc_info is slow; a significant chunk of all time spent unwinding is spent here.
check(unw_get_proc_info(&cursor, &pip));
assert((pip.lsda == 0) == (pip.handler == 0));
assert(pip.flags == 0);
if (VERBOSITY("cxx_unwind") >= 4) {
print_frame(&cursor, &pip);
}
// let the PythonUnwindSession know that we're in a new frame,
// giving it a chance to possibly add a traceback entry for
// it.
unwindingThroughFrame(unwind_session, &cursor);
// Skip frames without handlers
if (pip.handler == 0) {
continue;
}
RELEASE_ASSERT(pip.handler == (uintptr_t)__gxx_personality_v0,
"personality function other than __gxx_personality_v0; "
"don't know how to unwind through non-C++ functions");
// Don't call __gxx_personality_v0; we perform dispatch ourselves.
// 1. parse LSDA header
lsda_info_t info;
parse_lsda_header(&pip, &info);
call_site_entry_t entry;
{
// 2. Find our current IP in the call site table.
unw_word_t ip;
unw_get_reg(&cursor, UNW_REG_IP, &ip);
// ip points to the instruction *after* the instruction that caused the error - which is generally (always?)
// a call instruction - UNLESS we're in a signal frame, in which case it points at the instruction that
// caused the error. For now, we assume we're never in a signal frame. So, we decrement it by one.
//
// TODO: double-check that we never hit a signal frame.
--ip;
bool found = find_call_site_entry(&info, (const uint8_t*)ip, &entry);
// If we didn't find an entry, an exception happened somewhere exceptions should never happen; terminate
// immediately.
if (!found) {
panic();
}
}
// 3. Figure out what to do based on the call site entry.
if (!entry.landing_pad) {
// No landing pad means no exception handling or cleanup; keep unwinding!
continue;
}
// After this point we are guaranteed to resume something rather than unwinding further.
if (VERBOSITY("cxx_unwind") >= 4) {
print_lsda(&info);
}
int64_t switch_value = determine_action(&info, &entry);
if (switch_value != CLEANUP_ACTION) {
// we're transfering control to a non-cleanup landing pad.
// i.e. a catch block. thus ends our unwind session.
endPythonUnwindSession(unwind_session);
#if STAT_TIMERS
pyston::StatTimer::finishOverride();
#endif
}
static_assert(THREADING_USE_GIL, "have to make the unwind session usage in this file thread safe!");
// there is a python unwinding implementation detail leaked
// here - that the unwind session can be ended but its
// exception storage is still around.
//
// this manifests itself as this short window here where we've
// (possibly) ended the unwind session above but we still need
// to pass exc_data (which is the exceptionStorage for this
// unwind session) to resume().
//
// the only way this could bite us is if we somehow clobber
// the PythonUnwindSession's storage, or cause a GC to occur, before
// transfering control to the landing pad in resume().
//
resume(&cursor, entry.landing_pad, switch_value, exc_data);
}
// Hit end of stack! return & let unwindException determine what to do.
}