Background compiles give way to the lander: the Logbook statistics and the results refresher wait while [logbook] lander_lock is fresh (under 60 min); the statistics tools run below normal priority and a timeout ends the whole tree (an orphaned cl.exe went on compiling main at normal priority); a retried statistics run no longer relogs the same commits

harbor/results_refresh.py

@@ -13,6 +13,7 @@ Configured per project in the [logbook] table (main is [logbook] decomp):
     behaviour_every_hours = 12
     behaviour_window = "01-06"      from 01:00 to 06:00 local time; "" for any hour
 
+No run starts while the lander runs its gates ([logbook] lander_lock, harbor.lander_gate).
 One run at a time (the server runs one thread for every project), at the lowest process priority, into a .partial file
 that replaces the results only once it is complete. The match run holds the same per-checkout lock as re_match_program,
 so it waits its turn behind any other whole-program build of main.
@@ -31,7 +32,7 @@ import time
 import traceback
 from pathlib import Path
 
-from . import logbook
+from . import lander_gate, logbook
 
 JOBS = ("match", "behaviour")
 RESULTS_KEY = {"match": "match_results", "behaviour": "diffrun_results"}
@@ -180,14 +181,7 @@ def _spawn(argv, cwd, stdout, stderr):
 
 
 def _kill_tree(pid):
-    if os.name == "nt":
-        subprocess.run(["taskkill", "/PID", str(pid), "/T", "/F"], capture_output=True,
-                       creationflags=getattr(subprocess, "CREATE_NO_WINDOW", 0))
-    else:
-        try:
-            os.kill(pid, 9)
-        except OSError:
-            pass
+    lander_gate.kill_tree(pid)
 
 
 def _alive(pid):
@@ -315,6 +309,9 @@ def tick(project, now=None, hour=None):
     job, why = choose(settings(project), state, head, now, hour, requested, available)
     if not job:
         return {"idle": why, "head": head[:8]}
+    busy = lander_gate.lander_busy(project, now)
+    if busy:                                             # a request is kept for the next look
+        return {"waiting": busy, "job": job}
     if job == "match":
         from .util import HarborError
         try: