add test for sqlite rtree creating under high ds initialization concurrency

tests/python_tests/sqlite_rtree_test.py

@@ -0,0 +1,64 @@
+#!/usr/bin/env python
+
+from nose.tools import *
+from utilities import execution_path
+from Queue import Queue
+import threading
+
+import os, mapnik2
+import sqlite3
+
+def setup():
+    # All of the paths used are relative, if we run the tests
+    # from another directory we need to chdir()
+    os.chdir(execution_path('.'))
+
+NUM_THREADS = 10
+
+DB = '../data/sqlite/world.sqlite'
+
+def create_ds():
+    ds = mapnik2.SQLite(file=DB,table='world_merc')
+    fs = ds.all_features()
+
+if 'sqlite' in mapnik2.DatasourceCache.instance().plugin_names():
+    
+    def test_rtree_creation():
+
+        index = DB +'.index'
+        if os.path.exists(index):
+            os.unlink(index)
+
+        threads = []
+        for i in range(NUM_THREADS):
+            t = threading.Thread(target=create_ds)
+            t.start()
+            threads.append(t)
+
+        for i in threads:
+            i.join()
+        
+        if os.path.exists(index):
+            conn = sqlite3.connect(index)
+            cur = conn.cursor()
+            cur.execute("Select count(*) from idx_world_merc_GEOMETRY")
+            conn.commit()
+            eq_(cur.fetchone()[0],245)
+            cur.close()
+        else:
+            print 'index does not exist!'
+
+        if os.path.exists(index):
+            ds = mapnik2.SQLite(file=DB,table='world_merc')
+            fs = ds.all_features()
+            eq_(len(fs),245)
+            os.unlink(index)
+            ds = mapnik2.SQLite(file=DB,table='world_merc',use_spatial_index=False)
+            fs = ds.all_features()
+            eq_(len(fs),245)
+            eq_(os.path.exists(index),False)
+
+if __name__ == "__main__":
+    setup()
+    [eval(run)() for run in dir() if 'test_' in run]
+