pid1: rename job_check_gc to job_may_gc

The reasoning is the same as for unit_can_gc.

v2:
- rename can_gc to may_gc

src/core/job.c

@@ -1272,7 +1272,7 @@ int job_get_timeout(Job *j, usec_t *timeout) {
         return 1;
 }
 
-bool job_check_gc(Job *j) {
+bool job_may_gc(Job *j) {
         Unit *other;
         Iterator i;
         void *v;
@@ -1280,13 +1280,14 @@ bool job_check_gc(Job *j) {
         assert(j);
 
         /* Checks whether this job should be GC'ed away. We only do this for jobs of units that have no effect on their
-         * own and just track external state. For now the only unit type that qualifies for this are .device units. */
+         * own and just track external state. For now the only unit type that qualifies for this are .device units.
+         * Returns true if the job can be collected. */
 
         if (!UNIT_VTABLE(j->unit)->gc_jobs)
-                return true;
+                return false;
 
         if (sd_bus_track_count(j->bus_track) > 0)
-                return true;
+                return false;
 
         /* FIXME: So this is a bit ugly: for now we don't properly track references made via private bus connections
          * (because it's nasty, as sd_bus_track doesn't apply to it). We simply remember that the job was once
@@ -1296,11 +1297,11 @@ bool job_check_gc(Job *j) {
                 if (set_isempty(j->unit->manager->private_buses))
                         j->ref_by_private_bus = false;
                 else
-                        return true;
+                        return false;
         }
 
         if (j->type == JOB_NOP)
-                return true;
+                return false;
 
         /* If a job is ordered after ours, and is to be started, then it needs to wait for us, regardless if we stop or
          * start, hence let's not GC in that case. */
@@ -1312,7 +1313,7 @@ bool job_check_gc(Job *j) {
                         continue;
 
                 if (IN_SET(other->job->type, JOB_START, JOB_VERIFY_ACTIVE, JOB_RELOAD))
-                        return true;
+                        return false;
         }
 
         /* If we are going down, but something else is ordered After= us, then it needs to wait for us */
@@ -1324,7 +1325,7 @@ bool job_check_gc(Job *j) {
                         if (other->job->ignore_order)
                                 continue;
 
-                        return true;
+                        return false;
                 }
 
         /* The logic above is kinda the inverse of the job_is_runnable() logic. Specifically, if the job "we" is
@@ -1344,7 +1345,7 @@ bool job_check_gc(Job *j) {
          *
          */
 
-        return false;
+        return true;
 }
 
 void job_add_to_gc_queue(Job *j) {
@@ -1353,7 +1354,7 @@ void job_add_to_gc_queue(Job *j) {
         if (j->in_gc_queue)
                 return;
 
-        if (job_check_gc(j))
+        if (!job_may_gc(j))
                 return;
 
         LIST_PREPEND(gc_queue, j->unit->manager->gc_job_queue, j);

src/core/job.h

@@ -233,7 +233,7 @@ void job_shutdown_magic(Job *j);
 
 int job_get_timeout(Job *j, usec_t *timeout) _pure_;
 
-bool job_check_gc(Job *j);
+bool job_may_gc(Job *j);
 void job_add_to_gc_queue(Job *j);
 
 int job_get_before(Job *j, Job*** ret);

src/core/manager.c

@@ -1158,7 +1158,7 @@ static unsigned manager_dispatch_gc_job_queue(Manager *m) {
 
                 n++;
 
-                if (job_check_gc(j))
+                if (!job_may_gc(j))
                         continue;
 
                 log_unit_debug(j->unit, "Collecting job.");