_______                          .__ .__   .__   .__                 
      \      \    ____   __ __ _______ |__||  |  |  |  |__|  ____    ____  
      /   |   \ _/ __ \ |  |  \\_  __ \|  ||  |  |  |  |  | /  _ \  /    \ 
     /    |    \\  ___/ |  |  / |  | \/|  ||  |__|  |__|  |(  <_> )|   |  \
     \____|__  / \___  >|____/  |__|   |__||____/|____/|__| \____/ |___|  /
    =========\/======\/=================================================\/==
  v0.01 04/JUL/2007 (C) Copyright 2007-2007 Scott D. Yelich SOME RIGHTS RESERVED
 .,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.-*~'`^`'~*-,._.,-*~'`^`'~*-,. 


The software is released under Creative Commons - Attribution 3.0 unported 
see: http://creativecommons.org/licenses/by/3.0/legalcode

See "LICENSE" for text, URL above for latest version.

See "INSTALL" for information on installation (and usage).

See "TODO" for ideas about what could be done in a next version.

One weak spot with sqlite is with scaling and concurrency. Sqlite3
does have a few things to help with concurrency such as
sqlite3_busy_timeout and sqlite3_busy_handler. After fiddling with the
timeout feature for a while, it seemed that using the busy handler
would allow for more control. Yet, even with a busy handler, sqlite
may still return an error code. So along with concurrency, this
version of Xql3 (Xql3.cpp) uses C++ exceptions via an exception class
Xql3Exception (Xql3Exception.h) that returns both an error code as
well as an error message.

A timer using nanosleep is in the sleeper test program
(sleeper.cpp). Run lock (lock.cpp) to lock the sqlite database in
order to test concurrency (lock X where X is how many times a second
to lock/unlock the database). For fun, it's possible to even run
multiple copies of lock at the same time with different
parameters. While lock is running and the ":" (locked) and "."
(unlocked) are being displayed, run concurrency_v1
(concurrency_v1.cpp). Although most of the time the busy detection
will hit a busy/retry before all the sql statements and then be able
to run them all before another busy is detected, it is possible to
detect a lock/busy before any sqlite3 command.

Enjoy!

Scott