support concurrent builds

Add new table "building" for recording builds in progress. When a
concurrent build is issued, it will avoid building a source package that
is presently built. It will also avoid building for an architecture that
is presently built for. The latter condition helps reduce the number of
satisfiability issues.

1 files changed, 5 insertions, 0 deletions

diff --git a/schema.sql b/schema.sql
index d57867b..56184be 100644
--- a/schema.sql
+++ b/schema.sql
@@ -46,3 +46,8 @@ CREATE TABLE bugs (
 	title TEXT,
 	patched BOOLEAN NOT NULL CHECK (patched in (0, 1)));
 CREATE INDEX bugs_affects_index ON bugs(affects);
+
+CREATE TABLE building (
+	source TEXT NOT NULL,
+	architecture TEXT NOT NULL,
+	pid INTEGER NOT NULL);