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
      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
      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  }