scoped_ignore_signal: Use sigprocmask+sigtimedwait instead of signal
The problem with using signal(...) to temporarily ignore a signal, is
that that changes the the signal disposition for the whole process.
If multiple threads do it at the same time, you have a race.
Fix this by using sigprocmask + sigtimedwait to implement the ignoring
instead, if available, which I think probably means everywhere except
Windows nowadays. This way, we only change the signal mask for the
current thread, so there's no race.
Change-Id: Idfe3fb08327ef8cae926f3de9ee81c56a83b1738
gdbsupport/ChangeLog:
yyyy-mm-dd Pedro Alves <pedro@palves.net>
* scoped_ignore_signal.h
(scoped_ignore_signal::scoped_ignore_signal)
[HAVE_SIGPROCMASK]: Use sigprocmask to block the signal instead of
changing the signal disposition for the whole process.
(scoped_ignore_signal::~scoped_ignore_signal) [HAVE_SIGPROCMASK]:
Use sigtimedwait and sigprocmask to flush and unblock the signal.
2 files changed
