.Dd December 19, 2018
.Dt SQLITE3_THREADSAFE 3
.Os
.Sh NAME
.Nm sqlite3_threadsafe
.Nd Test To See If The Library Is Threadsafe
.Sh SYNOPSIS
.Ft int 
.Fo sqlite3_threadsafe
.Fa "void"
.Fc
.Sh DESCRIPTION
The sqlite3_threadsafe() function returns zero if and only if SQLite
was compiled with mutexing code omitted due to the SQLITE_THREADSAFE
compile-time option being set to 0.
.Pp
SQLite can be compiled with or without mutexes.
When the SQLITE_THREADSAFE C preprocessor macro is
1 or 2, mutexes are enabled and SQLite is threadsafe.
When the SQLITE_THREADSAFE macro is 0, the mutexes
are omitted.
Without the mutexes, it is not safe to use SQLite concurrently from
more than one thread.
.Pp
Enabling mutexes incurs a measurable performance penalty.
So if speed is of utmost importance, it makes sense to disable the
mutexes.
But for maximum safety, mutexes should be enabled.
The default behavior is for mutexes to be enabled.
.Pp
This interface can be used by an application to make sure that the
version of SQLite that it is linking against was compiled with the
desired setting of the SQLITE_THREADSAFE macro.
.Pp
This interface only reports on the compile-time mutex setting of the
SQLITE_THREADSAFE flag.
If SQLite is compiled with SQLITE_THREADSAFE=1 or =2 then mutexes are
enabled by default but can be fully or partially disabled using a call
to sqlite3_config() with the verbs SQLITE_CONFIG_SINGLETHREAD,
SQLITE_CONFIG_MULTITHREAD, or SQLITE_CONFIG_SERIALIZED.
The return value of the sqlite3_threadsafe() function shows only the
compile-time setting of thread safety, not any run-time changes to
that setting made by sqlite3_config().
In other words, the return value from sqlite3_threadsafe() is unchanged
by calls to sqlite3_config().
.Pp
See the threading mode documentation for additional information.
.Sh SEE ALSO
.Xr sqlite3_config 3 ,
.Xr SQLITE_CONFIG_SINGLETHREAD 3