Why there is thread race at the beginning?

Why there is thread race at the beginning?

References

Reference NO 1

http://en.wikipedia.org/wiki/Race_condition

Reference NO 2

http://stackoverflow.com/questions/34510/what-is-a-race-condition

Reference NO 3

http://valgrind.org/docs/manual/hg-manual.html

Reference NO 4

http://msdn.microsoft.com/en-us/library/1c9txz50.aspx

Reference NO 5

http://geekswithblogs.net/jolson/archive/2008/09/18/threading-basics-race-conditions-part-1.aspx

Reference NO 6

http://search.cpan.org/perldoc?threads

Reference NO 7

http://256.com/gray/docs/misc/producer_consumer_race_conditions/

Reference NO 8

http://www.qtcentre.org/threads/49815-QTimer-and-main-eventLoop-is-there-possible-race-condition