1 // To enable signal handling, the embedder should:
2 // 1. set Module.Py_EmscriptenSignalBuffer = some_shared_array_buffer;
3 // 2. set the Py_EMSCRIPTEN_SIGNAL_HANDLING flag to 1 as follows:
4 //    Module.HEAP8[Module._Py_EMSCRIPTEN_SIGNAL_HANDLING] = 1
5 //
6 // The address &Py_EMSCRIPTEN_SIGNAL_HANDLING is exported as
7 // Module._Py_EMSCRIPTEN_SIGNAL_HANDLING.
8 #include <emscripten.h>
9 #include "Python.h"
10 
11 EM_JS(int, _Py_CheckEmscriptenSignals_Helper, (void), {
12     if (!Module.Py_EmscriptenSignalBuffer) {
13         return 0;
14     }
15     try {
16         let result = Module.Py_EmscriptenSignalBuffer[0];
17         Module.Py_EmscriptenSignalBuffer[0] = 0;
18         return result;
19     } catch(e) {
20 #if !defined(NDEBUG)
21         console.warn("Error occurred while trying to read signal buffer:", e);
22 #endif
23         return 0;
24     }
25 });
26 
27 EMSCRIPTEN_KEEPALIVE int Py_EMSCRIPTEN_SIGNAL_HANDLING = 0;
28 
29 void
_Py_CheckEmscriptenSignals(void)30 _Py_CheckEmscriptenSignals(void)
31 {
32     if (!Py_EMSCRIPTEN_SIGNAL_HANDLING) {
33         return;
34     }
35     int signal = _Py_CheckEmscriptenSignals_Helper();
36     if (signal) {
37         PyErr_SetInterruptEx(signal);
38     }
39 }
40 
41 
42 #define PY_EMSCRIPTEN_SIGNAL_INTERVAL 50
43 static int emscripten_signal_clock = PY_EMSCRIPTEN_SIGNAL_INTERVAL;
44 
45 void
_Py_CheckEmscriptenSignalsPeriodically(void)46 _Py_CheckEmscriptenSignalsPeriodically(void)
47 {
48     if (!Py_EMSCRIPTEN_SIGNAL_HANDLING) {
49         return;
50     }
51     emscripten_signal_clock--;
52     if (emscripten_signal_clock == 0) {
53         emscripten_signal_clock = PY_EMSCRIPTEN_SIGNAL_INTERVAL;
54         _Py_CheckEmscriptenSignals();
55     }
56 }
57