phase1: raise priority of tag builds

.github/workflows/build-push.yml

@@ -8,7 +8,7 @@ on:
   pull_request:
 
 env:
-  BUILDBOT_VERSION: 3.8.0
+  BUILDBOT_VERSION: 3.9.0
   GITHUB_SHA_LEN: 8
 
 concurrency:

phase1/master.cfg

@@ -191,16 +191,20 @@ c["configurators"] = [
 
 
 @defer.inlineCallbacks
-def getNewestCompleteTime(bldr):
-    """Returns the complete_at of the latest completed and not SKIPPED
+def getNewestCompleteTimePrio(bldr):
+    """Returns the priority and the complete_at of the latest completed and not SKIPPED
     build request for this builder, or None if there are no such build
     requests. We need to filter out SKIPPED requests because we're
     using collapseRequests=True which is unfortunately marking all
     previous requests as complete when new buildset is created.
 
-    @returns: datetime instance or None, via Deferred
+    @returns: (priority, datetime instance or None), via Deferred
     """
 
+    prio = yield bldr.get_highest_priority()
+    if prio is None:
+        prio = 0
+
     bldrid = yield bldr.getBuilderId()
     completed = yield bldr.master.data.get(
         ("builders", bldrid, "buildrequests"),
@@ -212,7 +216,7 @@ def getNewestCompleteTime(bldr):
         limit=1,
     )
     if not completed:
-        return
+        return (prio, None)
 
     complete_at = completed[0]["complete_at"]
 
@@ -228,9 +232,9 @@ def getNewestCompleteTime(bldr):
     if last_build and last_build[0]:
         last_complete_at = last_build[0]["complete_at"]
         if last_complete_at and (last_complete_at > complete_at):
-            return last_complete_at
+            return (prio, last_complete_at)
 
-    return complete_at
+    return (prio, complete_at)
 
 
 @defer.inlineCallbacks
@@ -245,25 +249,28 @@ def prioritizeBuilders(master, builders):
     i = 1
     for bname in branchNames:
         bldrNamePrio[bname] = i
-        i += 1
 
     def is_building(bldr):
         return bool(bldr.building) or bool(bldr.old_building)
 
     def bldr_info(bldr):
-        d = defer.maybeDeferred(getNewestCompleteTime, bldr)
-        d.addCallback(lambda complete_at: (complete_at, bldr))
+        d = defer.maybeDeferred(getNewestCompleteTimePrio, bldr)
+        d.addCallback(lambda retval: (retval, bldr))
         return d
 
     def bldr_sort(item):
-        (complete_at, bldr) = item
+        ((hiprio, complete_at), bldr) = item
 
+        # check if we have some high prio build requests pending (i.e. tag builds),
+        # if so, front-run these builders, while preserving the per-branch static priority
         pos = 99
         for name, prio in bldrNamePrio.items():
             if bldr.name.startswith(name):
-                pos = prio
+                pos = prio + 50 - min(hiprio, 50)    # higher priority (larger positive number) raises position
                 break
 
+        # pos order: janitor/local (0), tag builds if any [1..50], !tag builds [51...]
+
         if not complete_at:
             date = datetime.min
             complete_at = date.replace(tzinfo=tzutc())
@@ -531,7 +538,7 @@ c["schedulers"].append(
 )
 
 c["schedulers"].append(
-    schedulers.Triggerable(name="trigger", builderNames=builderNames)
+    schedulers.Triggerable(name="trigger", builderNames=builderNames, priority=20)
 )
 
 ####### BUILDERS