Aside from the fact that the signal mask is still relevant in 2026 and even for multithreaded programs, that doesn't have anything to do with the fact that POSIX requires swapcontext to preserve it.
Aside from the fact that the signal mask is still relevant in 2026 and even for multithreaded programs, that doesn't have anything to do with the fact that POSIX requires swapcontext to preserve it.
In most cases you're already using signalfd in places where libdex runs.