NAME
sqlite3_threadsafe —
Test To See If The
Library Is Threadsafe
SYNOPSIS
int
sqlite3_threadsafe(
void);
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.
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.
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.
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.
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().
See the threading mode documentation for additional information.
SEE ALSO
sqlite3_config(3),
SQLITE_CONFIG_SINGLETHREAD(3)