解决方法
答案,以__handles.c的剪切和粘贴评论的形式 – 我知道,为什么不是每个人都想在那里寻找文档,对吧？
/* * use just one mutex for all the lists,this avoids any issues * with deadlocks,the performance issue should be minimal,if it * turns out to be a problem,we can readdress this * * We also have a mutex to protect the connection pooling code * * If compiled with thread support the DM allows four different * thread strategies * * Level 0 - Only the DM internal structures are protected * the driver is assumed to take care of it's self * * Level 1 - The driver is protected down to the statement level * each statement will be protected,and the same for the connect * level for connect functions,note that descriptors are considered * equal to statements when it comes to thread protection. * * Level 2 - The driver is protected at the connection level. only * one thread can be in a particular driver at one time * * Level 3 - The driver is protected at the env level,only one thing * at a time. * * By default the driver open connections with a lock level of 3,* this can be changed by adding the line * * Threading = N * * to the driver entry in odbcinst.ini,where N is the locking level * (0-3) * */
