Merge pull request #6827 from grondo/singleton

support `singleton` dependency scheme in job submission

Author: mergify[bot]

doc/man1/common/job-dependencies.rst

@@ -55,6 +55,14 @@ afterexcept:JOBID
    and a fatal job exception caused the transition to CLEANUP (e.g.,
    node failure, timeout, cancel, etc.).
 
+singleton
+   This dependency is satisfied when there are no other active jobs
+   of the same userid and job name which are not already held with
+   a singleton dependency. That is, a singleton can be the only
+   job with the same userid and job name in the SCHED state or later.
+   The singleton scheme requires an explicit job name using the
+   ``--job-name`` option.
+
 begin-time:TIMESTAMP
    This dependency is satisfied after TIMESTAMP, which is specified in
    floating point seconds since the UNIX epoch. See the ``--begin-time``

src/modules/job-manager/Makefile.am

@@ -74,6 +74,7 @@ libjob_manager_la_SOURCES = \
 	plugins/limit-job-size.c \
 	plugins/limit-duration.c \
 	plugins/dependency-after.c \
+	plugins/dependency-singleton.c \
 	plugins/begin-time.c \
 	plugins/update-duration.c \
 	plugins/validate-duration.c \

src/modules/job-manager/jobtap.c

@@ -48,6 +48,7 @@ extern int priority_default_plugin_init (flux_plugin_t *p);
 extern int limit_job_size_plugin_init (flux_plugin_t *p);
 extern int limit_duration_plugin_init (flux_plugin_t *p);
 extern int after_plugin_init (flux_plugin_t *p);
+extern int singleton_plugin_init (flux_plugin_t *p);
 extern int begin_time_plugin_init (flux_plugin_t *p);
 extern int validate_duration_plugin_init (flux_plugin_t *p);
 extern int update_duration_plugin_init (flux_plugin_t *p);
@@ -70,6 +71,7 @@ static struct jobtap_builtin jobtap_builtins [] = {
     { ".limit-job-size", limit_job_size_plugin_init },
     { ".limit-duration", limit_duration_plugin_init },
     { ".dependency-after", after_plugin_init },
+    { ".dependency-singleton", singleton_plugin_init },
     { ".begin-time", &begin_time_plugin_init },
     { ".validate-duration", &validate_duration_plugin_init },
     { ".update-duration", &update_duration_plugin_init },