Mutex Types
互斥量类型
#define SQLITE_MUTEX_FAST 0
#define SQLITE_MUTEX_RECURSIVE 1
#define SQLITE_MUTEX_STATIC_MASTER 2
#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
sqlite3_mutex_alloc（）接口接受一个参数，它是这些整数常量之一。
静态互斥量的集合可能会从一个 SQLite 版本更改为下一个版本。覆盖内置互斥逻辑的应用程序必须准备好适应其他静态互斥锁。
