1
0
mirror of https://github.com/tmux/tmux.git synced 2025-04-02 05:48:49 +00:00

Wait for the cgroup request job to complete

The StartTransientUnit call returns as soon as the job is enqueued, but
does not wait for systemd to actually do the work.  Wait for the job
completion signal before continuing to exec, or until 1 second has
passed.
This commit is contained in:
Daniel De Graaf 2025-03-26 19:54:46 -04:00
parent d34cf29b38
commit 289eb5ccd9

View File

@ -75,16 +75,53 @@ fail:
return (-1);
}
struct job_watch {
const char* path;
int done;
};
static int
job_removed_handler(sd_bus_message *m, void *userdata, sd_bus_error *ret_error)
{
struct job_watch *watch = userdata;
const char* path = NULL;
uint32_t id;
int r;
(void)ret_error;
/* This handler could be called during sd_bus_call. */
if (watch->path == NULL) {
return 0;
}
r = sd_bus_message_read(m, "uo", &id, &path);
if (r < 0) {
return (r);
}
if (strcmp(path, watch->path) == 0) {
watch->done = 1;
}
return (0);
}
int
systemd_move_to_new_cgroup(char **cause)
{
sd_bus_error error = SD_BUS_ERROR_NULL;
sd_bus_message *m = NULL, *reply = NULL;
sd_bus *bus = NULL;
sd_bus_slot *slot = NULL;
char *name, *desc, *slice;
sd_id128_t uuid;
int r;
uint64_t elapsed_usec;
pid_t pid, parent_pid;
struct job_watch watch = {};
struct timeval start, now;
gettimeofday(&start, NULL);
/* Connect to the session bus. */
r = sd_bus_default_user(&bus);
@ -94,6 +131,20 @@ systemd_move_to_new_cgroup(char **cause)
goto finish;
}
/* Start watching for JobRemoved events */
r = sd_bus_match_signal(bus, &slot,
"org.freedesktop.systemd1",
"/org/freedesktop/systemd1",
"org.freedesktop.systemd1.Manager",
"JobRemoved",
job_removed_handler,
&watch);
if (r < 0) {
xasprintf(cause, "failed to create match signal: %s",
strerror(-r));
goto finish;
}
/* Start building the method call. */
r = sd_bus_message_new_method_call(bus, &m,
"org.freedesktop.systemd1",
@ -224,10 +275,49 @@ systemd_move_to_new_cgroup(char **cause)
goto finish;
}
/* Get the job (object path) from the reply */
r = sd_bus_message_read(reply, "o", &watch.path);
if (r < 0) {
xasprintf(cause, "failed to parse method reply: %s",
strerror(-r));
goto finish;
}
while (!watch.done) {
/* Process events, invoking callbacks that may set watch.done */
r = sd_bus_process(bus, NULL);
if (r < 0) {
xasprintf(cause, "failed waiting for cgroup allocation: %s",
strerror(-r));
goto finish;
}
/* A zero return means we should wait for events */
if (r != 0) {
continue;
}
gettimeofday(&now, NULL);
elapsed_usec = (now.tv_sec - start.tv_sec) * 1000000 + now.tv_usec - start.tv_usec;
if (elapsed_usec >= 1000000) {
xasprintf(cause, "timeout waiting for cgroup allocation");
goto finish;
}
r = sd_bus_wait(bus, 1000000 - elapsed_usec);
if (r < 0) {
xasprintf(cause, "failed waiting for cgroup allocation: %s",
strerror(-r));
goto finish;
}
}
finish:
sd_bus_error_free(&error);
sd_bus_message_unref(m);
sd_bus_message_unref(reply);
sd_bus_slot_unref(slot);
sd_bus_unref(bus);
return (r);