1 /*-------------------------------------------------------------------------
2 timeout.c - source file for running ucSim within the regression tests
4 Written By - Bernhard Held . bernhard@bernhardheld.de (2001)
6 This program is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by the
8 Free Software Foundation; either version 2, or (at your option) any
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20 In other words, you are welcome to use, share and improve this program.
21 You are forbidden to forbid anyone else to use, share and improve
22 what you give them. Help stamp out software-hoarding!
23 -------------------------------------------------------------------------*/
25 #define PROGNAME "timeout"
27 #define USAGE PROGNAME " : 1.00\n" \
28 "Usage : " PROGNAME " timeout_in_seconds filename [arguments]\n" \
29 " ´filename´ is executed, the arguments are passed to ´filename´.\n" \
30 " When ´filename´exits before the timeout expires, the\n" \
31 " exit-status of ´filename´ is returned.\n" \
32 " When the timeout expires before ´filename´ exits, ´filename´\n" \
33 " will be killed and an exit-status of 1 is returned.\n"
35 /* First the program tries to limit the maximum CPU-time to the timeout-value.
36 Then the child is run with execvp().
38 It's not possible to limit the CPU-time under Cygwin (V1.3.3). If setrlimit (RLIMIT_CPU, rlp)
39 fails, the program will fork() and run the child with execvp(). The fork/exec pair is slow on
40 Cygwin, but what else can we do? The parent sleeps until:
41 - a signal shows the child´s exitus
42 The exit status of the child is returned.
44 The child will be killed.
50 #include <sys/types.h>
52 #include <sys/resource.h>
55 /* Get the status from all child processes that have terminated, without ever waiting.
56 This function is designed to be a handler for SIGCHLD, the signal that indicates
57 that at least one child process has terminated.
58 http://www.cs.utah.edu/dept/old/texinfo/glibc-manual-0.02/library_23.html#SEC401
66 sigchld_handler (int signum)
74 pid = waitpid (WAIT_ANY, &status, WNOHANG);
75 if (WEXITSTATUS (status))
76 exit_status = 1; // WEXITSTATUS(status);
77 /* pid == -1: no children */
78 /* pid == 0: no children to be noticed */
86 main (int argc, char * const *argv)
88 /* if getrlimit() / setrlimit() succeed, then no fork is neeeded */
97 fprintf (stderr, USAGE);
100 timeout = atol (argv[1]);
103 fprintf (stderr, "Error parameter " PROGNAME ": must be a non-zero dezimal value\n");
107 /* try to use getrlimit() / setrlimit() for RLIMIT_CPU */
108 /* to limit the CPU-time */
109 if (getrlimit (RLIMIT_CPU, &rl) == 0)
111 rl.rlim_cur = timeout;
112 if (setrlimit (RLIMIT_CPU, &rl) == 0)
117 { /* the CPU-time is limited: simple execvp */
119 /* s51 prints warnings on stderr: */
120 /* serial input/output interface connected to a non-terminal file. */
121 /* We'll redirect here stderr to stdout, which will be redirected */
122 /* to /dev/null by the shell. The shell could also redirect stderr */
123 /* to /dev/null, but then this program doesn't have the chance to */
124 /* output any real error. */
125 old_stderr = dup (STDERR_FILENO);
126 dup2 (STDOUT_FILENO, STDERR_FILENO);
127 /* shouldn't return */
128 execvp (argv[2], argv + 2);
130 dup2 (old_stderr, STDERR_FILENO);
132 return 1; /* Error */
136 /* do it the hard way: fork/exec */
137 signal (SIGCHLD, sigchld_handler);
141 /* s51 prints warnings on stderr: */
142 /* serial input/output interface connected to a non-terminal file. */
143 /* We'll redirect here stderr to stdout, which will be redirected */
144 /* to /dev/null by the shell. The shell could also redirect stderr */
145 /* to /dev/null, but then this program doesn't have the chance to */
146 /* output any real error. */
147 old_stderr = dup (STDERR_FILENO);
148 dup2 (STDOUT_FILENO, STDERR_FILENO);
149 /* shouldn't return */
150 execvp (argv[2], argv + 2);
152 dup2 (old_stderr, STDERR_FILENO);
154 return 1; /* Error */
158 /* this timeout is hopefully aborted by a SIGCHLD */
160 fprintf (stderr, PROGNAME ": timeout, killing child %s\n", argv[2]);
161 kill (pid_child, SIGTERM);
162 return 1; /* Error */