runqueue: Simplify scenequeue unskippable calculation

The existing code to compute the 'unskippable' setscene task list is overcomlicated,
so replace it with something functionally equivalent but simpler and more efficient.

We don't need to process all chains, just the 'top' ones to the first setscene tasks.

This also makes the code more readable.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 13 insertions, 32 deletions

diff --git a/lib/bb/runqueue.py b/lib/bb/runqueue.py
index c06e4199d..ec98411fc 100644
--- a/lib/bb/runqueue.py
+++ b/lib/bb/runqueue.py
@@ -2280,7 +2280,7 @@ class SQData(object):
         # Cache of stamp files so duplicates can't run in parallel
         self.stamps = {}
         # Setscene tasks directly depended upon by the build
-        self.unskippable = []
+        self.unskippable = set()
         # List of setscene tasks which aren't present
         self.outrightfail = []
         # A list of normal tasks a setscene task covers
@@ -2357,38 +2357,19 @@ def build_scenequeue_data(sqdata, rqdata, rq, cooker, stampcache, sqrq):
 
     # Build a list of setscene tasks which are "unskippable"
     # These are direct endpoints referenced by the build
-    endpoints2 = {}
-    sq_revdeps2 = {}
-    sq_revdeps_new2 = {}
-    def process_endpoints2(endpoints):
-        newendpoints = {}
-        for point, task in endpoints.items():
-            tasks = set([point])
-            if task:
-                tasks |= task
-            if sq_revdeps_new2[point]:
-                tasks |= sq_revdeps_new2[point]
-            sq_revdeps_new2[point] = set()
-            if point in rqdata.runq_setscene_tids:
-                sq_revdeps_new2[point] = tasks
-            for dep in rqdata.runtaskentries[point].depends:
-                if point in sq_revdeps2[dep]:
-                    sq_revdeps2[dep].remove(point)
-                if tasks:
-                    sq_revdeps_new2[dep] |= tasks
-                if (len(sq_revdeps2[dep]) == 0 or len(sq_revdeps_new2[dep]) != 0) and dep not in rqdata.runq_setscene_tids:
-                    newendpoints[dep] = tasks
-        if len(newendpoints) != 0:
-            process_endpoints2(newendpoints)
+    # Take the build endpoints (no revdeps) and find the sstate tasks they depend upon
+    new = True
     for tid in rqdata.runtaskentries:
-        sq_revdeps2[tid] = copy.copy(rqdata.runtaskentries[tid].revdeps)
-        sq_revdeps_new2[tid] = set()
-        if (len(sq_revdeps2[tid]) == 0) and tid not in rqdata.runq_setscene_tids:
-            endpoints2[tid] = set()
-    process_endpoints2(endpoints2)
-    for tid in rqdata.runq_setscene_tids:
-        if sq_revdeps_new2[tid]:
-            sqdata.unskippable.append(tid)
+        if len(rqdata.runtaskentries[tid].revdeps) == 0:
+            sqdata.unskippable.add(tid)
+    while new:
+        new = False
+        for tid in sqdata.unskippable.copy():
+            if tid in rqdata.runq_setscene_tids:
+                continue
+            sqdata.unskippable.remove(tid)
+            sqdata.unskippable |= rqdata.runtaskentries[tid].depends
+            new = True
 
     rqdata.init_progress_reporter.next_stage(len(rqdata.runtaskentries))