nx_signalfd.nx

nx_signalfd.nx -- Linux signalfd(2) wrapper. signalfd lets the kernel deliver signals via file descriptor reads instead of signal handlers. This is the modern way to integrate signal handling with poll/epoll-driven event loops: you add the signalfd to your poll set and react to signals inline, no async-signal-safe constraints. Linux RV64 syscall: 74 (signalfd4). To receive a signal via signalfd, you ALSO need to mask the signal in the process's normal signal mask via rt_sigprocmask (otherwise the kernel still delivers it normally). We expose nx_signalfd_install which does both steps. Read returns one or more struct signalfd_siginfo records (128 bytes each); the first 4 bytes are the signal number (i32). Pairs with nx_signal (constants + sigaction) + nx_poll (consumer in event loops).