4 ms·
The lack of signals in Windows is the very opposite of a flaw! - Windows has just never pretended you can get away without a message loop.
by tom_ 8y ago
The lack of signals in Windows is the very opposite of a flaw! - Windows has just never pretended you can get away without a message loop.
- quotemstr 8y agoWindows does have signals! It just splits them into a few facilities. POSIX "synchronous" signals correspond to SEH exceptions and can be handled roughly the same way --- except that signals have process global handlers and Windows has thread-local ones, because the glibc people are sticks in the mud and are hostile to any attempt to make signals suck less. For asynchronous signals, like SIGINT, Windows create a new thread out of thin air to deliver your app a notification. That's not really all that much better than a signal from a concurrency perspective. Windows even has APCs, which are like regular signals that are delivered only at explicit system call boundaries. Every operating system needs some mechanism to tell a process to do something. Windows has evolved an approach that isn't all that different from Unix signal handling.
- cryptonector 8y agoSpawning a new thread to handle a signal is much better than preemption: you then have no concerns about async-signal-safety that aren't plain old thread-safety concerns. I'd much rather have thread-safety constraints than async-signal-safety constraints.
- quotemstr 8y agoSort of. At least you can mask signals. I agree that threads are probably better overall, but I don't think it's a huge difference.
- Vogtinator 8y agoLinux can do that as well, see SIGEV_THREAD.
- cryptonector 8y agoYes, of course signals are easily the worst thing in Unix, but job control is nice.
- zvrba 8y agoIt's already there: https://docs.microsoft.com/en-us/windows/desktop/ProcThread/job-objects https://docs.microsoft.com/en-us/windows/desktop/ProcThread/... You can set various limits, though I haven't seen functions to stop/resume a job.
- ygra 8y agoYou can suspend and resume threads, so if you model your jobs with processes that could be used for that, I guess.
- loa-in-backup 8y ago*with threads
- ygra 8y agoProcesses. A quick skim of the documentation linked by the person I answered suggests that processes can be associated with a job object, but threads cannot. But a process cannot really be suspended directly, except by suspending all its threads.