"""
TestCases for testing the locking sub-system.
"""

import sys, os, string
import tempfile
import time
from pprint import pprint
from whrandom import random

try:
    from threading import Thread, currentThread
    have_threads = 1
except ImportError:
    have_threads = 0


import unittest
from test.test_support import verbose

from bsddb import db


#----------------------------------------------------------------------

class LockingTestCase(unittest.TestCase):

    def setUp(self):
        homeDir = os.path.join(os.path.dirname(sys.argv[0]), 'db_home')
        self.homeDir = homeDir
        try: os.mkdir(homeDir)
        except os.error: pass
        self.env = db.DBEnv()
        self.env.open(homeDir, db.DB_THREAD | db.DB_INIT_MPOOL |
                      db.DB_INIT_LOCK | db.DB_CREATE)


    def tearDown(self):
        self.env.close()
        import glob
        files = glob.glob(os.path.join(self.homeDir, '*'))
        for file in files:
            os.remove(file)


    def test01_simple(self):
        if verbose:
            print '\n', '-=' * 30
            print "Running %s.test01_simple..." % self.__class__.__name__

        anID = self.env.lock_id()
        if verbose:
            print "locker ID: %s" % anID
        lock = self.env.lock_get(anID, "some locked thing", db.DB_LOCK_WRITE)
        if verbose:
            print "Aquired lock: %s" % lock
        time.sleep(1)
        self.env.lock_put(lock)
        if verbose:
            print "Released lock: %s" % lock




    def test02_threaded(self):
        if verbose:
            print '\n', '-=' * 30
            print "Running %s.test02_threaded..." % self.__class__.__name__

        threads = []
        threads.append(Thread(target = self.theThread, args=(5, db.DB_LOCK_WRITE)))
        threads.append(Thread(target = self.theThread, args=(1, db.DB_LOCK_READ)))
        threads.append(Thread(target = self.theThread, args=(1, db.DB_LOCK_READ)))
        threads.append(Thread(target = self.theThread, args=(1, db.DB_LOCK_WRITE)))
        threads.append(Thread(target = self.theThread, args=(1, db.DB_LOCK_READ)))
        threads.append(Thread(target = self.theThread, args=(1, db.DB_LOCK_READ)))
        threads.append(Thread(target = self.theThread, args=(1, db.DB_LOCK_WRITE)))
        threads.append(Thread(target = self.theThread, args=(1, db.DB_LOCK_WRITE)))
        threads.append(Thread(target = self.theThread, args=(1, db.DB_LOCK_WRITE)))

        for t in threads:
            t.start()
        for t in threads:
            t.join()



    def theThread(self, sleepTime, lockType):
        name = currentThread().getName()
        if lockType ==  db.DB_LOCK_WRITE:
            lt = "write"
        else:
            lt = "read"

        anID = self.env.lock_id()
        if verbose:
            print "%s: locker ID: %s" % (name, anID)

        lock = self.env.lock_get(anID, "some locked thing", lockType)
        if verbose:
            print "%s: Aquired %s lock: %s" % (name, lt, lock)

        time.sleep(sleepTime)

        self.env.lock_put(lock)
        if verbose:
            print "%s: Released %s lock: %s" % (name, lt, lock)


#----------------------------------------------------------------------

def suite():
    theSuite = unittest.TestSuite()

    if have_threads:
        theSuite.addTest(unittest.makeSuite(LockingTestCase))
    else:
        theSuite.addTest(unittest.makeSuite(LockingTestCase, 'test01'))

    return theSuite


if __name__ == '__main__':
    unittest.main( defaultTest='suite' )
