--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/multiprocessing.py	Thu Dec 15 18:21:41 2011 +0100
@@ -0,0 +1,78 @@
+#!/usr/bin/env python3
+'''Multiprocessing test.
+
+PgManager is partially safe against process forking.
+
+You can create connection credentials (create_conn) in main process, then fork
+and continue working with pgmanager in children processes. You can call create_conn again
+in children, but new connection credentials will be accessible only from process
+where it was created -- no sharing between processes.
+
+get_conn and cursor will still work after fork. Connections from parent process will
+be forgotten, that cannot be used un child process. 
+
+Connections cannot be shared between processes, DO NOT:
+ * get_conn, then fork, then put_conn
+ * get_conn, then fork, then use the connection, then .close()
+
+Good usage:
+ * create_conn, fork, get_conn, cursor, etc.
+
+Basically, you can transfer only information from create_conn(), nothing else.
+
+'''
+
+
+import multiprocessing
+
+from config import Config
+from pgtoolkit import pgmanager
+
+
+def sub1(id):
+    with pgm.cursor() as curs:
+        print('[%d] pgconn: %d' % (multiprocessing.current_process().pid, curs.connection.get_backend_pid()))
+        print('[%d] update' % multiprocessing.current_process().pid)
+        curs.execute('''UPDATE test SET name = 'multi-1' WHERE id=%s''', [id])
+        print('[%d] commit' % multiprocessing.current_process().pid)
+        curs.connection.commit()
+
+def sub2(id):
+    pgm = pgmanager.get_instance()
+    with pgm.cursor() as curs:
+        print('[%d] pgconn: %d' % (multiprocessing.current_process().pid, curs.connection.get_backend_pid()))
+        print('[%d] update' % multiprocessing.current_process().pid)
+        curs.execute('''UPDATE test SET name = 'multi-2' WHERE id=%s''', [id])
+        print('[%d] commit' % multiprocessing.current_process().pid)
+        curs.connection.commit()
+
+
+cfg = Config('tests.conf')
+pgm = pgmanager.get_instance()
+pgm.create_conn(**cfg)
+
+with pgm.cursor() as curs:
+    print('[%d] pgconn: %d' % (multiprocessing.current_process().pid, curs.connection.get_backend_pid()))    
+    print('[%d] insert' % multiprocessing.current_process().pid)
+    curs.execute('''INSERT INTO test (name) VALUES ('multi') RETURNING id''')
+    id = curs.fetchone()[0]
+    curs.connection.commit()
+    
+    print('[%d] update' % multiprocessing.current_process().pid)
+    curs.execute('''UPDATE test SET name = 'multi-main' WHERE id=%s''', [id])
+    # not committed
+
+p1 = multiprocessing.Process(target=sub1, args=[id])
+p1.start()
+p2 = multiprocessing.Process(target=sub2, args=[id])
+p2.start()
+
+with pgm.cursor() as curs:
+    print('[%d] commit' % multiprocessing.current_process().pid)
+    curs.connection.commit()
+
+print('join')
+p1.join()
+p2.join()
+
+print('done')