1. Overview SQLite supports three different threading modes: Single-thread. In this mode, all mutexes are disabled and SQLite is unsafe to use in more than a single thread at once. Multi-thread. In this mode, SQLite can be safely used by ... 

sqlite3_db_mutex()

This interface returns a pointer the sqlite3_mutex object that serializes access to the database connection given in the argument when the threading mode is Serialized. If the threading mode is Single-thread or Multi-thread then this routine returns a ... 

sqlite3_mutex_alloc(), sqlite3_mutex_free(), sqlite3_mutex_enter(), sqlite3_mutex_try(), sqlite3_mutex_leave()

The SQLite core uses these routines for thread synchronization. Though they are intended for internal use by SQLite, code that links against SQLite is permitted to use any of these routines. The SQLite source code contains multiple implementations of these ... 

 ... If each thread were assigned a priority, then instead of just signaling the threads in arbitrary order as this implementation does, higher priority threads could be signaled before lower priority threads. If a "DROP TABLE" or "DROP INDEX" SQL command ... 

sqlite3_threadsafe()

 ... Without the mutexes, it is not safe to use SQLite concurrently from more than one thread. Enabling mutexes incurs a measurable performance penalty. So if speed is of utmost importance, it makes sense to disable the mutexes. But for maximum ... 

 ... The mutex subsystem is only required for applications that access SQLite from multiple threads. For single-threaded applications, or applications which only call SQLite from a single thread, the mutex subsystem can be completely disabled by recompiling with the following ... 

SQLITE_CONFIG_SINGLETHREAD, SQLITE_CONFIG_MULTITHREAD, SQLITE_CONFIG_SERIALIZED, SQLITE_CONFIG_MALLOC, SQLITE_CONFIG_GETMALLOC, SQLITE_CONFIG_SCRATCH ... 

 ... This option sets the threading mode to Single-thread. In other words, it disables all mutexing and puts SQLite into a mode where it can only be used by a single thread. If SQLite is compiled with the SQLITE_THREADSAFE=0 ... 

sqlite3_db_name()

 ... The string might be deallocated by any operation that changes the schema, including ATTACH or DETACH or calls to sqlite3_serialize() or sqlite3_deserialize(), even operations that occur on a different thread. Applications that need to remember the string long-term should ... 

 ... The sqlite3_enable_shared_cache() interface now applies to all threads within a process, not to just the one thread in which it was run. The sqlite3_soft_heap_limit() interface now applies to all threads within a process, not to just the one thread in ... 

 ... 1.0 FUNCTIONALITY With asynchronous I/O, write requests are handled by a separate thread running in the background. This means that the thread that initiates a database write does not have to wait for (sometimes slow) disk I/O ...