Explicit exit from main #15299
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Explicit exit from main #15299
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In a MT environment the main thread's fiber may be resumed by any thread, which may terminate the program, and would return from another thread that the process' main thread, which may be This patches instead explicitly exits from `main` and `wmain`. For backward compatibility reason (win32's `wmain` and wasi's `__main_argc_argv` call `main`), the default `main` still returns, and is replaced for UNIX targets.
ysbaddaden
commented
Dec 20, 2024
ysbaddaden
commented
Dec 20, 2024
straight-shoota
approved these changes
Dec 20, 2024
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In a MT environment such as proposed in crystal-lang/rfcs#2, the main thread's fiber may be resumed by any thread, and it may return which would terminate the program... but it might return from another thread that the process' main thread, which may be unexpected by the OS.
This patch instead explicitly exits from
mainandwmain.For backward compatibility reasons (win32
wmainand wasi__main_argc_argvboth callmainandand are documented to do so), the defaultmainstill returns, but is being replaced for UNIX targets by one that exits.Maybe the OS actual entrypoint could merely call
Crystal.maininstead ofmainand explicitely exit (there wouldn't be a globalmainexcept forUNIX), but this is out of scope for this PR.