signals.c

   1 #include <stdlib.h>
   2 #include <signal.h>
   3 #include <unistd.h>
   4
   5 #include "trinity.h"    // __unused__
   6 #include "params.h"     // debug
   7 #include "pids.h"
   8 #include "signals.h"
   9 #include "shm.h"
  10
  11 jmp_buf ret_jump;
  12
  13 int sigwas;
  14
  15 static void ctrlc_handler(__unused__ int sig)
  16 {
  17         shm->exit_reason = EXIT_SIGINT;
  18 }
  19
  20 static void sighandler(int sig)
  21 {
  22         int slot;
  23
  24         sigwas = sig;
  25
  26         switch (sig) {
  27         case SIGALRM:
  28                 slot = find_pid_slot(getpid());
  29                 if (slot == PIDSLOT_NOT_FOUND)
  30                         _exit(EXIT_SUCCESS);    /* Hell knows what happened, just bail. */
  31
  32                 /* Check if we're blocking because we're stuck on an fd. */
  33                 if (check_if_fd(slot) == TRUE) {
  34
  35                         /* avoid doing it again from other threads. */
  36                         shm->fd_lifetime = 0;
  37
  38                         /* TODO: Somehow mark the fd in the parent not to be used again too. */
  39                 }
  40
  41                 /* Re-arm the alarm. */
  42                 alarm(1);
  43
  44                 /* TODO: If we get back here after the 10s alarm, we should exit instead of longjmp */
  45
  46                 /* Jump back, maybe we'll make progress. */
  47                 (void)signal(sig, sighandler);
  48                 siglongjmp(ret_jump, 1);
  49                 break;
  50
  51         default:
  52                 _exit(EXIT_SUCCESS);
  53         }
  54 }
  55
  56 void mask_signals_child(void)
  57 {
  58         struct sigaction sa;
  59         sigset_t ss;
  60         int i;
  61
  62         for (i = 1; i < 512; i++) {
  63                 (void)sigfillset(&ss);
  64                 sa.sa_flags = SA_RESTART;
  65                 sa.sa_handler = sighandler;
  66                 sa.sa_mask = ss;
  67                 (void)sigaction(i, &sa, NULL);
  68         }
  69         /* we want default behaviour for child process signals */
  70         (void)signal(SIGCHLD, SIG_DFL);
  71
  72         /* ignore signals we don't care about */
  73         (void)signal(SIGFPE, SIG_IGN);
  74         (void)signal(SIGXCPU, SIG_IGN);
  75         (void)signal(SIGTSTP, SIG_IGN);
  76         (void)signal(SIGWINCH, SIG_IGN);
  77         (void)signal(SIGIO, SIG_IGN);
  78         (void)signal(SIGPIPE, SIG_IGN);
  79
  80         /* Ignore the RT signals. */
  81         for (i = SIGRTMIN; i <= SIGRTMAX; i++)
  82                 (void)signal(i, SIG_IGN);
  83
  84         /* If we are in debug mode, we want segfaults and core dumps */
  85         if (debug == TRUE) {
  86                 (void)signal(SIGABRT, SIG_DFL);
  87                 (void)signal(SIGSEGV, SIG_DFL);
  88         }
  89
  90         /* trap ctrl-c */
  91         (void)signal(SIGINT, ctrlc_handler);
  92 }
  93
  94
  95 void setup_main_signals(void)
  96 {
  97         /* we want default behaviour for child process signals */
  98         (void)signal(SIGFPE, SIG_DFL);
  99         (void)signal(SIGCHLD, SIG_DFL);
 100
 101         (void)signal(SIGINT, ctrlc_handler);
 102 }