Add an action to cancel all builds in a jobset eval

src/lib/Hydra/Helper/Nix.pm

@@ -21,7 +21,8 @@ our @EXPORT = qw(
     getEvals getMachines
     pathIsInsidePrefix
     captureStdoutStderr run grab
-    getTotalShares);
+    getTotalShares
+    cancelBuilds);
 
 
 sub getHydraHome {
@@ -43,11 +44,12 @@ sub getHydraConfig {
 # doesn't work.
 sub txn_do {
     my ($db, $coderef) = @_;
+    my $res;
     while (1) {
         eval {
-            $db->txn_do($coderef);
+            $res = $db->txn_do($coderef);
         };
-        last if !$@;
+        return $res if !$@;
         die $@ unless $@ =~ "database is locked";
     }
 }
@@ -542,4 +544,21 @@ sub getTotalShares {
 }
 
 
+sub cancelBuilds($$) {
+    my ($db, $builds) = @_;
+    return txn_do($db, sub {
+        $builds = $builds->search({ finished => 0, busy => 0 });
+        my $n = $builds->count;
+        my $time = time();
+        $builds->update(
+            { finished => 1,
+            , iscachedbuild => 0, buildstatus => 4 # = cancelled
+            , starttime => $time
+            , stoptime => $time
+            });
+        return $n;
+    });
+}
+
+
 1;