timeout: add support for "timeout -k KILL_SECS"

function                                             old     new   delta
timeout_main                                         307     373     +66
timeout_wait                                           -      42     +42
.rodata                                           104201  104203      +2
packed_usage                                       34097   34096      -1
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 2/1 up/down: 110/-1)            Total: 109 bytes

Signed-off-by: Matthew Slowe <foo@mafoo.org.uk>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 32 insertions, 11 deletions

diff --git a/coreutils/timeout.c b/coreutils/timeout.c
index 8485e1e7d..06108f315 100644
--- a/coreutils/timeout.c
+++ b/coreutils/timeout.c
@@ -39,13 +39,29 @@
 //kbuild:lib-$(CONFIG_TIMEOUT) += timeout.o
 
 //usage:#define timeout_trivial_usage
-//usage:       "[-s SIG] SECS PROG ARGS"
+//usage:       "[-s SIG] [-k KILL_SECS] SECS PROG ARGS"
 //usage:#define timeout_full_usage "\n\n"
 //usage:       "Run PROG. Send SIG to it if it is not gone in SECS seconds.\n"
 //usage:       "Default SIG: TERM."
+//usage:       "If it still exists in KILL_SECS seconds, send KILL.\n"
 
 #include "libbb.h"
 
+static NOINLINE int timeout_wait(int timeout, pid_t pid)
+{
+        /* Just sleep(HUGE_NUM); kill(parent) may kill wrong process! */
+        while (1) {
+                sleep1();
+                if (--timeout <= 0)
+                        break;
+                if (kill(pid, 0)) {
+                        /* process is gone */
+                        return EXIT_SUCCESS;
+                }
+        }
+        return EXIT_FAILURE;
+}
+
 int timeout_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int timeout_main(int argc UNUSED_PARAM, char **argv)
 {
@@ -53,23 +69,29 @@ int timeout_main(int argc UNUSED_PARAM, char **argv)
         int status;
         int parent = 0;
         int timeout;
+        int kill_timeout;
         pid_t pid;
 #if !BB_MMU
         char *sv1, *sv2;
 #endif
         const char *opt_s = "TERM";
+        char *opt_k = NULL;
 
         /* -p option is not documented, it is needed to support NOMMU. */
 
         /* -t SECONDS; -p PARENT_PID */
         /* '+': stop at first non-option */
-        getopt32(argv, "+s:" USE_FOR_NOMMU("p:+"), &opt_s, &parent);
+        getopt32(argv, "+s:k:" USE_FOR_NOMMU("p:+"), &opt_s, &opt_k, &parent);
         /*argv += optind; - no, wait for bb_daemonize_or_rexec! */
 
         signo = get_signum(opt_s);
         if (signo < 0)
                 bb_error_msg_and_die("unknown signal '%s'", opt_s);
 
+        kill_timeout = 0;
+        if (opt_k)
+                kill_timeout = parse_duration_str(opt_k);
+
         if (!argv[optind])
                 bb_show_usage();
         timeout = parse_duration_str(argv[optind++]);
@@ -103,17 +125,16 @@ int timeout_main(int argc UNUSED_PARAM, char **argv)
                 bb_daemonize_or_rexec(0, argv);
                 /* Here we are grandchild. Sleep, then kill grandparent */
  grandchild:
-                /* Just sleep(HUGE_NUM); kill(parent) may kill wrong process! */
-                while (1) {
-                        sleep1();
-                        if (--timeout <= 0)
-                                break;
-                        if (kill(parent, 0)) {
-                                /* process is gone */
+                if (timeout_wait(timeout, parent) == EXIT_SUCCESS)
+                        return EXIT_SUCCESS;
+                kill(parent, signo);
+
+                if (kill_timeout > 0) {
+                        if (timeout_wait(kill_timeout, parent) == EXIT_SUCCESS)
                                 return EXIT_SUCCESS;
-                        }
+                        kill(parent, SIGKILL);
                 }
-                kill(parent, signo);
+
                 return EXIT_SUCCESS;
         }