iexec: enable not exitting together with the child

This commit is contained in:
Přemysl Eric Janouch 2023-06-19 18:57:52 +02:00
parent 4cc1baf429
commit 7e30dfb6f0
Signed by: p
GPG Key ID: A0420B94F92B9493

83
iexec.c
View File

@ -24,20 +24,35 @@
// This can also work on BSD if someone puts in the effort to support kqueue
#include <sys/inotify.h>
static pid_t g_child;
static bool g_restarting = false;
static int g_inotify_fd, g_inotify_wd;
static struct
{
pid_t child; ///< Watched child or 0
bool exits; ///< Don't restart child when it exits
bool respawn; ///< Respawn child ASAP
bool killing; ///< Waiting for child to die
int inotify_fd, inotify_wd;
}
g;
// Note that this program doesn't queue up file-based restarts
static void
handle_inotify_event (const struct inotify_event *e, const char *base)
{
if (e->wd != g_inotify_wd || strcmp (e->name, base))
if (e->wd != g.inotify_wd || strcmp (e->name, base))
return;
print_debug ("file changed, killing child");
g_restarting = true;
if (g_child >= 0 && kill (g_child, SIGINT))
print_error ("kill: %s", strerror (errno));
if (g.child)
{
print_debug ("file changed, killing child");
if (kill (g.child, SIGINT))
print_error ("kill: %s", strerror (errno));
g.killing = true;
}
else
{
print_debug ("file changed, respawning");
g.respawn = true;
}
}
static void
@ -46,7 +61,7 @@ handle_file_change (const char *base)
char buf[4096];
ssize_t len = 0;
struct inotify_event *e = NULL;
while ((len = read (g_inotify_fd, buf, sizeof buf)) > 0)
while ((len = read (g.inotify_fd, buf, sizeof buf)) > 0)
for (char *ptr = buf; ptr < buf + len; ptr += sizeof *e + e->len)
handle_inotify_event ((e = (struct inotify_event *) buf), base);
}
@ -54,9 +69,9 @@ handle_file_change (const char *base)
static void
spawn (char *argv[])
{
if ((g_child = fork ()) == -1)
if ((g.child = fork ()) == -1)
exit_fatal ("fork: %s", strerror (errno));
else if (g_child)
else if (g.child)
return;
// A linker can create spurious CLOSE_WRITEs, wait until it's executable
@ -69,23 +84,22 @@ spawn (char *argv[])
}
static bool
check_child_death (char *argv[])
check_child_death (void)
{
if (waitpid (g_child, NULL, WNOHANG) != g_child)
int status = 0;
if (waitpid (g.child, &status, WNOHANG) != g.child)
return true;
if (!g_restarting)
g.child = 0;
if (!g.killing)
{
print_debug ("child died on its own, not respawning");
return false;
}
else
{
print_debug ("child died on request, respawning");
spawn (argv);
g_restarting = false;
return true;
return g.exits;
}
g.killing = false;
print_debug ("child died on request, respawning");
return g.respawn = true;
}
static void
@ -102,6 +116,7 @@ main (int argc, char *argv[])
static const struct opt opts[] =
{
{ 'f', "file", "PATH", 0, "watch this path rather than the program" },
{ 'e', "exits", NULL, 0, "allow the program to exit on its own" },
{ 'd', "debug", NULL, 0, "run in debug mode" },
{ 'h', "help", NULL, 0, "display this help and exit" },
{ 'V', "version", NULL, 0, "output version information and exit" },
@ -121,6 +136,9 @@ main (int argc, char *argv[])
case 'f':
target = optarg;
break;
case 'e':
g.exits = true;
break;
case 'd':
g_debug_mode = true;
break;
@ -164,25 +182,30 @@ main (int argc, char *argv[])
char *path = NULL;
char *dir = dirname ((path = xstrdup (target)));
if ((g_inotify_fd = inotify_init1 (IN_NONBLOCK)) < 0)
if ((g.inotify_fd = inotify_init1 (IN_NONBLOCK)) < 0)
exit_fatal ("inotify_init1: %s", strerror (errno));
if ((g_inotify_wd = inotify_add_watch (g_inotify_fd,
if ((g.inotify_wd = inotify_add_watch (g.inotify_fd,
dir, IN_MOVED_TO | IN_CLOSE_WRITE)) < 0)
exit_fatal ("inotify_add_watch: %s", strerror (errno));
free (path);
char *base = basename ((path = xstrdup (target)));
spawn (argv);
g.respawn = true;
do
{
fd_set r; FD_SET (g_inotify_fd, &r);
(void) pselect (g_inotify_fd + 1, &r, NULL, NULL, NULL, &orig);
if (g.respawn)
{
spawn (argv);
g.respawn = false;
}
fd_set r; FD_SET (g.inotify_fd, &r);
(void) pselect (g.inotify_fd + 1, &r, NULL, NULL, NULL, &orig);
handle_file_change (base);
}
while (check_child_death (argv));
while (check_child_death ());
free (path);
close (g_inotify_fd);
xclose (g.inotify_fd);
return EXIT_SUCCESS;
}