text: """
  Copyright (c) 2008-2017, Jesus Cea Avion <jcea@jcea.es>
  All rights reserved.
  
  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions
  are met:
  
      1. Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
  
      2. Redistributions in binary form must reproduce the above
      copyright notice, this list of conditions and the following
      disclaimer in the documentation and/or other materials provided
      with the distribution.
  
      3. Neither the name of Jesus Cea Avion nor the names of its
      contributors may be used to endorse or promote products derived
      from this software without specific prior written permission.
  
      THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
      CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
      INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
      MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
      DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS
      BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
      EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
              TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
              DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
      ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
      TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
      THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
      SUCH DAMAGE.
      """
  
  """TestCases for checking that it does not segfault when a DBEnv object
  is closed before its DB objects.
  """
  
  import os, sys
  import unittest
  
  from .test_all import db, test_support, verbose, get_new_environment_path, get_new_database_path
  
  # We're going to get warnings in this module about trying to close the db when
  # its env is already closed.  Let's just ignore those.
  try:
      import warnings
  except ImportError:
      pass
  else:
      warnings.filterwarnings('ignore',
                              message='DB could not be closed in',
                              category=RuntimeWarning)
  
  
  #----------------------------------------------------------------------
  
  class DBEnvClosedEarlyCrash(unittest.TestCase):
      def setUp(self):
          self.homeDir = get_new_environment_path()
          self.filename = "test"
  
      def tearDown(self):
          test_support.rmtree(self.homeDir)
  
      def test01_close_dbenv_before_db(self):
          dbenv = db.DBEnv()
          dbenv.open(self.homeDir,
                     db.DB_INIT_CDB| db.DB_CREATE |db.DB_THREAD|db.DB_INIT_MPOOL,
                     0o666)
  
          d = db.DB(dbenv)
          d2 = db.DB(dbenv)
          d.open(self.filename, db.DB_BTREE, db.DB_CREATE | db.DB_THREAD, 0o666)
  
          self.assertRaises(db.DBNoSuchFileError, d2.open,
                  self.filename+"2", db.DB_BTREE, db.DB_THREAD, 0o666)
  
          d.put("test","this is a test")
          self.assertEqual(d.get("test"), "this is a test", "put!=get")
          dbenv.close()  # This "close" should close the child db handle also
          self.assertRaises(db.DBError, d.get, "test")
  
      def test02_close_dbenv_before_dbcursor(self):
          dbenv = db.DBEnv()
          dbenv.open(self.homeDir,
                     db.DB_INIT_CDB| db.DB_CREATE |db.DB_THREAD|db.DB_INIT_MPOOL,
                     0o666)
  
          d = db.DB(dbenv)
          d.open(self.filename, db.DB_BTREE, db.DB_CREATE | db.DB_THREAD, 0o666)
  
          d.put("test","this is a test")
          d.put("test2","another test")
          d.put("test3","another one")
          self.assertEqual(d.get("test"), "this is a test", "put!=get")
          c=d.cursor()
          c.first()
          next(c)
          d.close()  # This "close" should close the child db handle also
       # db.close should close the child cursor
          self.assertRaises(db.DBError,c.__next__)
  
          d = db.DB(dbenv)
          d.open(self.filename, db.DB_BTREE, db.DB_CREATE | db.DB_THREAD, 0o666)
          c=d.cursor()
          c.first()
          next(c)
          dbenv.close()
      # The "close" should close the child db handle also, with cursors
          self.assertRaises(db.DBError, c.__next__)
  
      def test03_close_db_before_dbcursor_without_env(self):
          import os.path
          path=os.path.join(self.homeDir,self.filename)
          d = db.DB()
          d.open(path, db.DB_BTREE, db.DB_CREATE | db.DB_THREAD, 0o666)
  
          d.put("test","this is a test")
          d.put("test2","another test")
          d.put("test3","another one")
          self.assertEqual(d.get("test"), "this is a test", "put!=get")
          c=d.cursor()
          c.first()
          next(c)
          d.close()
      # The "close" should close the child db handle also
          self.assertRaises(db.DBError, c.__next__)
  
      def test04_close_massive(self):
          dbenv = db.DBEnv()
          dbenv.open(self.homeDir,
                     db.DB_INIT_CDB| db.DB_CREATE |db.DB_THREAD|db.DB_INIT_MPOOL,
                     0o666)
  
          dbs=[db.DB(dbenv) for i in range(16)]
          cursors=[]
          for i in dbs :
              i.open(self.filename, db.DB_BTREE, db.DB_CREATE | db.DB_THREAD, 0o666)
  
          dbs[10].put("test","this is a test")
          dbs[10].put("test2","another test")
          dbs[10].put("test3","another one")
          self.assertEqual(dbs[4].get("test"), "this is a test", "put!=get")
  
          for i in dbs :
              cursors.extend([i.cursor() for j in range(32)])
  
          for i in dbs[::3] :
              i.close()
          for i in cursors[::3] :
              i.close()
  
      # Check for missing exception in DB! (after DB close)
          self.assertRaises(db.DBError, dbs[9].get, "test")
  
      # Check for missing exception in DBCursor! (after DB close)
          self.assertRaises(db.DBError, cursors[101].first)
  
          cursors[80].first()
          next(cursors[80])
          dbenv.close()  # This "close" should close the child db handle also
      # Check for missing exception! (after DBEnv close)
          self.assertRaises(db.DBError, cursors[80].__next__)
  
      def test05_close_dbenv_delete_db_success(self):
          dbenv = db.DBEnv()
          dbenv.open(self.homeDir,
                     db.DB_INIT_CDB| db.DB_CREATE |db.DB_THREAD|db.DB_INIT_MPOOL,
                     0o666)
  
          d = db.DB(dbenv)
          d.open(self.filename, db.DB_BTREE, db.DB_CREATE | db.DB_THREAD, 0o666)
  
          dbenv.close()  # This "close" should close the child db handle also
  
          del d
          try:
              import gc
          except ImportError:
              gc = None
          if gc:
              # force d.__del__ [DB_dealloc] to be called
              gc.collect()
  
      def test06_close_txn_before_dup_cursor(self) :
          dbenv = db.DBEnv()
          dbenv.open(self.homeDir,db.DB_INIT_TXN | db.DB_INIT_MPOOL |
                  db.DB_INIT_LOG | db.DB_CREATE)
          d = db.DB(dbenv)
          txn = dbenv.txn_begin()
          d.open(self.filename, dbtype = db.DB_HASH, flags = db.DB_CREATE,
                  txn=txn)
          d.put("XXX", "yyy", txn=txn)
          txn.commit()
          txn = dbenv.txn_begin()
          c1 = d.cursor(txn)
          c2 = c1.dup()
          self.assertEqual(("XXX", "yyy"), c1.first())
  
          # Not interested in warnings about implicit close.
          import warnings
          with warnings.catch_warnings() :
              warnings.filterwarnings("ignore")
              txn.commit()
  
          self.assertRaises(db.DBCursorClosedError, c2.first)
  
      def test07_close_db_before_sequence(self):
          import os.path
          path=os.path.join(self.homeDir,self.filename)
          d = db.DB()
          d.open(path, db.DB_BTREE, db.DB_CREATE | db.DB_THREAD, 0o666)
          dbs=db.DBSequence(d)
          d.close()  # This "close" should close the child DBSequence also
          dbs.close()  # If not closed, core dump (in Berkeley DB 4.6.*)
  
  #----------------------------------------------------------------------
  
  def test_suite():
      suite = unittest.TestSuite()
      suite.addTest(unittest.makeSuite(DBEnvClosedEarlyCrash))
      return suite
  
  
  if __name__ == '__main__':
      unittest.main(defaultTest='test_suite')
  