run: add --job-mode= argument (#34708)

systemctl has a --job-mode= argument, and adding the same argument to
systemd-run is useful for starting transient scopes with dependencies.
For example, if a transient scope BindsTo a service that is stopping,
specifying --job-mode=replace will wait for the service to stop before
starting it again, while the default job mode of "fail" will cause the
systemd-run invocation to fail.

src/basic/unit-def.c

@@ -344,6 +344,20 @@ static const char* const notify_access_table[_NOTIFY_ACCESS_MAX] = {
 
 DEFINE_STRING_TABLE_LOOKUP(notify_access, NotifyAccess);
 
+static const char* const job_mode_table[_JOB_MODE_MAX] = {
+        [JOB_FAIL]                 = "fail",
+        [JOB_REPLACE]              = "replace",
+        [JOB_REPLACE_IRREVERSIBLY] = "replace-irreversibly",
+        [JOB_ISOLATE]              = "isolate",
+        [JOB_FLUSH]                = "flush",
+        [JOB_IGNORE_DEPENDENCIES]  = "ignore-dependencies",
+        [JOB_IGNORE_REQUIREMENTS]  = "ignore-requirements",
+        [JOB_TRIGGERING]           = "triggering",
+        [JOB_RESTART_DEPENDENCIES] = "restart-dependencies",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(job_mode, JobMode);
+
 SpecialGlyph unit_active_state_to_glyph(UnitActiveState state) {
         static const SpecialGlyph map[_UNIT_ACTIVE_STATE_MAX] = {
                 [UNIT_ACTIVE]       = SPECIAL_GLYPH_BLACK_CIRCLE,

src/basic/unit-def.h

@@ -283,6 +283,20 @@ typedef enum NotifyAccess {
         _NOTIFY_ACCESS_INVALID = -EINVAL,
 } NotifyAccess;
 
+typedef enum JobMode {
+        JOB_FAIL,                /* Fail if a conflicting job is already queued */
+        JOB_REPLACE,             /* Replace an existing conflicting job */
+        JOB_REPLACE_IRREVERSIBLY,/* Like JOB_REPLACE + produce irreversible jobs */
+        JOB_ISOLATE,             /* Start a unit, and stop all others */
+        JOB_FLUSH,               /* Flush out all other queued jobs when queueing this one */
+        JOB_IGNORE_DEPENDENCIES, /* Ignore both requirement and ordering dependencies */
+        JOB_IGNORE_REQUIREMENTS, /* Ignore requirement dependencies */
+        JOB_TRIGGERING,          /* Adds TRIGGERED_BY dependencies to the same transaction */
+        JOB_RESTART_DEPENDENCIES,/* A "start" job for the specified unit becomes "restart" for depending units */
+        _JOB_MODE_MAX,
+        _JOB_MODE_INVALID = -EINVAL,
+} JobMode;
+
 char* unit_dbus_path_from_name(const char *name);
 int unit_name_from_dbus_path(const char *path, char **name);
 
@@ -346,4 +360,7 @@ UnitDependency unit_dependency_from_string(const char *s) _pure_;
 const char* notify_access_to_string(NotifyAccess i) _const_;
 NotifyAccess notify_access_from_string(const char *s) _pure_;
 
+const char* job_mode_to_string(JobMode t) _const_;
+JobMode job_mode_from_string(const char *s) _pure_;
+
 SpecialGlyph unit_active_state_to_glyph(UnitActiveState state);