This way, if xz is stopped the elapsed time and estimated time
remaining won't get confused by the amount of time spent in
the stopped state.
This raises SIGSTOP. It's not clear to me if this is the correct way.
POSIX and glibc docs say that SIGTSTP shouldn't stop the process if
it is orphaned but this commit doesn't attempt to handle that.
Search for SIGTSTP in section 2.4.3:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html
I don't know the details but I have an impression that there's
no problem in practice if using GCC since people have built xz
with GCC (without patching xz), but renaming the variable cannot
hurt either.
Thanks to Mark Ashley.
It is possible that a signal to set user_abort arrives right
before a blocking system call is made. In this case the call
may block until another signal arrives, while the wanted
behavior is to make xz clean up and exit as soon as possible.
After this commit, the race condition is avoided with the
input side which already uses non-blocking I/O. The output
side still uses blocking I/O and thus has the race condition.
Calling raise() to kill xz when user has pressed C-c
is a bit verbose on OS/2 and DOS/DJGPP. Instead of
calling raise(), set only the exit status to 1.
If signal handlers haven't been established, then it's
useless to try to block them, especially since the sigset_t
used for blocking hasn't been initialized yet.
Separate a few reusable components from XZ Utils specific
code. The reusable code is now in "tuklib" modules. A few
more could be separated still, e.g. bswap.h.
Fix some bugs in lzmainfo.
Fix physmem and cpucores code on OS/2. Thanks to Elbert Pol
for help.
Add OpenVMS support into physmem. Add a few #ifdefs to ease
building XZ Utils on OpenVMS. Thanks to Jouk Jansen for the
original patch.
