http://lists.mysql.com/commits/57725

Vladislav Vaintroub	2008-11-03
Cleanup CMakeLists.txt(s) - remove winsock2 (ws2_32) from 
TARGET_LINK_LIBRARIES. 
      
Every exe or dll linked with mysys needs ws2_32, because
mysys uses winsock function WSAStartup in my_init().
However, there is no need to explicitely add ws2_32 to
the list of TARGET_LINK_LIBRARIES multiple times. 
Visual Studio comes with a handy pragma that tells linker
to add library. So patch replaces bunch of ws2_32 in 
CMakeLists with  single pragma comment(lib,"ws2_32")
in my_init.c
      
Additionally, reference to non-existing "debug" library
has been removed from TARGET_LINK_LIBRARIES. The correct
name of the library is "dbug".

htttp://lists.mysql.com/commits/50957?f=plain
      
Always use TLS functions instead of __declspec(thread) to access 
thread local storage variables.
The change removes the necessity to recomplile the same source
files twice -  with USE_TLS for DLLs and without USE_TLS for EXEs.
Real benefit of this change is better readability and maintainability
of TLS functions within MySQL.
              
There is a performance loss using TlsXXX functions compared to __declspec 
but the difference is negligible in practice. In a sysbench-like benchmark 
I ran with with TlsGetValue, pthread_[get|set]_specific was called 600000000 
times and took 0.17sec of total 35min CPU time, or 0.008%.

Update default.conf.