1*11efff7fSkettenis /* This testcase is part of GDB, the GNU debugger.
2*11efff7fSkettenis 
3*11efff7fSkettenis    Copyright 2004 Free Software Foundation, Inc.
4*11efff7fSkettenis 
5*11efff7fSkettenis    This program is free software; you can redistribute it and/or modify
6*11efff7fSkettenis    it under the terms of the GNU General Public License as published by
7*11efff7fSkettenis    the Free Software Foundation; either version 2 of the License, or
8*11efff7fSkettenis    (at your option) any later version.
9*11efff7fSkettenis 
10*11efff7fSkettenis    This program is distributed in the hope that it will be useful,
11*11efff7fSkettenis    but WITHOUT ANY WARRANTY; without even the implied warranty of
12*11efff7fSkettenis    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13*11efff7fSkettenis    GNU General Public License for more details.
14*11efff7fSkettenis 
15*11efff7fSkettenis    You should have received a copy of the GNU General Public License
16*11efff7fSkettenis    along with this program; if not, write to the Free Software
17*11efff7fSkettenis    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18*11efff7fSkettenis 
19*11efff7fSkettenis    Please email any bugs, comments, and/or additions to this file to:
20*11efff7fSkettenis    bug-gdb@prep.ai.mit.edu  */
21*11efff7fSkettenis 
22*11efff7fSkettenis #include <signal.h>
23*11efff7fSkettenis #include <stdio.h>
24*11efff7fSkettenis #include <stdlib.h>
25*11efff7fSkettenis #include <string.h>
26*11efff7fSkettenis #include <sys/time.h>
27*11efff7fSkettenis 
28*11efff7fSkettenis enum level { MAIN, OUTER, INNER, LEAF, NR_LEVELS };
29*11efff7fSkettenis 
30*11efff7fSkettenis /* Levels completed flag.  */
31*11efff7fSkettenis volatile enum level level = NR_LEVELS;
32*11efff7fSkettenis 
33*11efff7fSkettenis void catcher (int signal);
34*11efff7fSkettenis 
35*11efff7fSkettenis void
thrower(enum level next_level,int sig,int itimer,int on_stack)36*11efff7fSkettenis thrower (enum level next_level, int sig, int itimer, int on_stack)
37*11efff7fSkettenis {
38*11efff7fSkettenis   level = next_level;
39*11efff7fSkettenis   /* Set up the signal handler.  */
40*11efff7fSkettenis   {
41*11efff7fSkettenis     struct sigaction act;
42*11efff7fSkettenis     memset (&act, 0, sizeof (act));
43*11efff7fSkettenis     act.sa_handler = catcher;
44*11efff7fSkettenis     act.sa_flags |= on_stack;
45*11efff7fSkettenis     sigaction (sig, &act, NULL);
46*11efff7fSkettenis   }
47*11efff7fSkettenis   /* Set up a one-off timer.  A timer, rather than SIGSEGV, is used as
48*11efff7fSkettenis      after a timer handler finishes the interrupted code can safely
49*11efff7fSkettenis      resume.  */
50*11efff7fSkettenis   {
51*11efff7fSkettenis     struct itimerval itime;
52*11efff7fSkettenis     memset (&itime, 0, sizeof (itime));
53*11efff7fSkettenis     itime.it_value.tv_usec = 250 * 1000;
54*11efff7fSkettenis     setitimer (itimer, &itime, NULL);
55*11efff7fSkettenis   }
56*11efff7fSkettenis   /* Wait.  */
57*11efff7fSkettenis   while (level != LEAF);
58*11efff7fSkettenis }
59*11efff7fSkettenis 
60*11efff7fSkettenis void
catcher(int signal)61*11efff7fSkettenis catcher (int signal)
62*11efff7fSkettenis {
63*11efff7fSkettenis   /* Find the next level.  */
64*11efff7fSkettenis   switch (level)
65*11efff7fSkettenis     {
66*11efff7fSkettenis     case MAIN:
67*11efff7fSkettenis       thrower (OUTER, SIGALRM, ITIMER_REAL, SA_ONSTACK);
68*11efff7fSkettenis       break;
69*11efff7fSkettenis     case OUTER:
70*11efff7fSkettenis       thrower (INNER, SIGVTALRM, ITIMER_VIRTUAL, SA_ONSTACK);
71*11efff7fSkettenis       break;
72*11efff7fSkettenis     case INNER:
73*11efff7fSkettenis       level = LEAF;
74*11efff7fSkettenis       return;
75*11efff7fSkettenis     }
76*11efff7fSkettenis }
77*11efff7fSkettenis 
78*11efff7fSkettenis 
main()79*11efff7fSkettenis main ()
80*11efff7fSkettenis {
81*11efff7fSkettenis   /* Set up the altstack.  */
82*11efff7fSkettenis   {
83*11efff7fSkettenis     static char stack[SIGSTKSZ * NR_LEVELS];
84*11efff7fSkettenis     struct sigaltstack alt;
85*11efff7fSkettenis     memset (&alt, 0, sizeof (alt));
86*11efff7fSkettenis     alt.ss_sp = stack;
87*11efff7fSkettenis     alt.ss_size = SIGSTKSZ;
88*11efff7fSkettenis     alt.ss_flags = 0;
89*11efff7fSkettenis     if (sigaltstack (&alt, NULL) < 0)
90*11efff7fSkettenis       {
91*11efff7fSkettenis 	perror ("sigaltstack");
92*11efff7fSkettenis 	exit (0);
93*11efff7fSkettenis       }
94*11efff7fSkettenis   }
95*11efff7fSkettenis   level = MAIN;
96*11efff7fSkettenis   catcher (0);
97*11efff7fSkettenis }
98