A game suspends its own thread with SuspendThread under Wine on macOS

Symptoms

The game pauses its own game thread with SuspendThread while its window is inactive, and at start on some desktops. Under Wine on macOS this is one more place where a thread is stopped by a signal while a 32-bit game runs under Rosetta.

Cause

Wine on macOS suspends a thread by sending it a signal (inferred from Wine's design). Nobody has measured whether this causes a failure by itself. In POD the calls were patched out during the search for the wow64cpu fault. The fault stayed.

What to do

If you suspect it, skip the calls. Patch each SuspendThread and ResumeThread call on the game thread to pop its argument and return 0 (add esp, 4; xor eax, eax in place of the call). The game then keeps running in the background instead of pausing. Record it as a Deviation.

Tried

• Skipping every SuspendThread and ResumeThread call in POD: the game no longer pauses. The wow64cpu fault stays.