SIGSEGV on macOS with rayon

[rust-or]

SIGSEGV on macOS with rayon

[jajhall]

Can we move this discussion to ERGO-Code/HiGHS#1005

[yongqli]

Running it under lldb I get:

Process 66711 stopped
* thread #35, stop reason = EXC_BAD_ACCESS (code=1, address=0x20)
    frame #0: 0x0000000100170c0d `HighsMipSolverData::evaluateRootNode() [inlined] HighsSplitDeque::getCurrentHead(this=0x0000000000000000) const at HighsSplitDeque.h:481:49 [opt]
   478
   479     int getOwnerId() const { return ownerData.ownerId; }
   480
-> 481     int getCurrentHead() const { return ownerData.head; }
   482
   483     HighsSplitDeque* getWorkerById(int id) const {
   484       return ownerData.workers[id].get();

[lovasoa]

@jajhall : it looks like we have thread safety issues. Help would be welcome !