/* signal.c: a Hugh-approved signal handler. */ #include <signal.h> #include <setjmp.h> #include "rc.h" #include "sigmsgs.h" #include "jbwrap.h" Jbwrap slowbuf; volatile SIG_ATOMIC_T slow, interrupt_happened; void (*sighandlers[NUMOFSIGNALS])(int); static volatile SIG_ATOMIC_T sigcount, caught[NUMOFSIGNALS]; extern void catcher(int s) { if (forked) exit(1); /* exit unconditionally on a signal in a child process */ if (caught[s] == 0) { sigcount++; caught[s] = 1; } signal(s, catcher); interrupt_happened = TRUE; if (slow) longjmp(slowbuf.j, 1); } extern void sigchk() { void (*h)(int); int s, i; if (sigcount == 0) return; /* ho hum; life as usual */ if (forked) exit(1); /* exit unconditionally on a signal in a child process */ for (i = 0, s = -1; i < NUMOFSIGNALS; i++) if (caught[i] != 0) { s = i; --sigcount; caught[s] = 0; break; } if (s == -1) panic("all-zero sig vector with nonzero sigcount"); if ((h = sighandlers[s]) == SIG_DFL) panic("caught signal set to SIG_DFL"); if (h == SIG_IGN) panic("caught signal set to SIG_IGN"); (*h)(s); } extern void (*rc_signal(int s, void (*h)(int)))(int) { void (*old)(int); SIGCHK; old = sighandlers[s]; if (h == SIG_DFL || h == SIG_IGN) { signal(s, h); sighandlers[s] = h; } else { sighandlers[s] = h; signal(s, catcher); } return old; } extern void initsignal() { void (*h)(int); int i; for (i = 1; i < NUMOFSIGNALS; i++) { if ((h = signal(i, SIG_DFL)) != SIG_DFL) signal(i, h); sighandlers[i] = h; } }