Re: OT: Windows (Was: Re: Open Source does not mean easily

In article <vlip2c$24ccb$1@dont-email.me>,  <Muttley@DastardlyHQ.org> wrote:

On Mon, 06 Jan 2025 16:46:56 GMT
scott@slp53.sl.home (Scott Lurndal) wibbled:

Muttley@DastardlyHQ.org writes:

On Mon, 06 Jan 2025 15:05:33 GMT
scott@slp53.sl.home (Scott Lurndal) wibbled:

Muttley@DastardlyHQ.org writes:

In Windows yes, which frankly is probably not a coincidence. Not so much
in unix unless you're writing a GUI program.

>
ASTs and unix signals have similar semantics.  It's certainly possible to
use, for example, SIGIO in a similar manner to the VMS AST, where the
AST signals I/O completion and the AST handler initiates a subsequent
operation.

>
Unix signals should only be used to set flags that are then read later.

>
You're opinion is not widely shared.   Note that the POSIX specification
carefully notes which interfaces are not signal-safe.

>
ITYF it is VERY widely shared and having a signal safe API function is only
step 2 - plenty of the functions in the program itself or 3rd party library
functions are probably not re-entrant safe and even if they are, having
code stomp over itself - eg if in the middle of writing a log message then a
signal is generated which tried to write a log message itself - is a very
poor way to write code.

So don't write code that way.  It does not follow that the only
thing you can do in a signal handler is an some atomic flag
somewhere.

- Dan C.