Re: win32, ctrl-c, sleep, and signals

This is caused by the 'safe signals' that were introduced by 5.8.0. The sleep is treated a single opcode and so the signal is not seen until after the opcode completes. See the 'safe signals' section of perl58delta. Also see perl581delta for how to bypass this and get the old unsafe behaviour back.

c:\test>set PERL_SIGNALS=unsafe

c:\test>p1
[0] Perl> $SIG{ INT } = sub{ print 'Caught signal INT'; };;
[0] Perl> print 'still here' while sleep 10;;
still here
Caught signal INT
still here
Terminating on signal SIGBREAK(21)
[download]

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Comment on Re: win32, ctrl-c, sleep, and signals Download Code

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Re^2: win32, ctrl-c, sleep, and signals by SirBones (Friar) on May 30, 2006 at 16:38 UTC
This is caused by the 'safe signals' that were introduced by 5.8.0. Fair enough, but that doesn't seem to explain why I get different behavior on Linux (immediate exit), where I'm running Perl 5.8.0. Thanks, Ken "This bounty hunter is my kind of scum: Fearless and inventive." --J.T. Hutt	[reply]
Re^3: win32, ctrl-c, sleep, and signals by BrowserUk (Patriarch) on May 30, 2006 at 17:11 UTC
You have to remember that Win32 does not have signals as a native concept. Perl's support for them is simulated and limited, and is actually implemented via the process message queue. This is the code that implements the signal emulations from win32.c: Read more... (2 kB) Setting the environment variable `PERL_SIGNALS=unsafe` allows ^C to interupt sleep. Without it, the signal handler doesn't get invoked until the sleep is over. Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal? "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l] [select]
Re^2: win32, ctrl-c, sleep, and signals by sgifford (Prior) on May 30, 2006 at 16:40 UTC
Are you sure? It works fine for me on Unix with perl 5.8.3. It seems to me that `sleep` would qualify as a "potentially blocking operation" mentioned in perl58delta... -- sgifford's Web page	[reply] [d/l]
Re^3: win32, ctrl-c, sleep, and signals by BrowserUk (Patriarch) on May 30, 2006 at 17:12 UTC
Are you sure? Yes. See Re^3: win32, ctrl-c, sleep, and signals. Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal? "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l]


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