Re: Desperately missing a working "pselect()" or similar...

David Schwartz
2001-10-05T23:43:10Z

>> A technique I used in a similar situation once went something like:

>> tv.tv_sec=bignum;
>> tv.tv_usec = 0;
>> enable_signals();
>> select(nfds, &readfds,&writefds,0,&tv);

>> and have the signal handlers set tv.tv_sec to 0. (tv is a global
>>variable).

>I've thought about that, but I haven't been able to find any guarantee that
>there will be no user space futzing around with &tv, like a library wrapper
>that copies tv to another spot in memory and invokes the syscall with that
>address.

This will commonly happen if, for example, the user-side timeval structure
contains seconds and microseconds and the kernel-side structure contains
seconds and nanoseconds. The signal might occur after the library has
performed the structure conversion.

DS