__TZ_LOCK(3) NEWLIB __TZ_LOCK(3)NAME
9.10 `__tz_lock', `__tz_unlock'--lock time zone global variables
SYNOPSIS
#include "local.h"
void __tz_lock (void);
void __tz_unlock (void);
DESCRIPTION
The `tzset' facility functions call these functions when they need to
ensure the values of global variables. The version of these routines
supplied in the library use the lock API defined in sys/lock.h. If
multiple threads of execution can call the time functions and give up
scheduling in the middle, then you you need to define your own versions
of these functions in order to safely lock the time zone variables dur‐
ing a call. If you do not, the results of `localtime', `mktime',
`ctime', and `strftime' are undefined.
The lock `__tz_lock' may not be called recursively; that is, a call
`__tz_lock' will always lock all subsequent `__tz_lock' calls until the
corresponding `__tz_unlock' call on the same thread is made.
SEE ALSO__tz_lock is part of the library. The full documentation for is main‐
tained as a Texinfo manual. If info and are properly installed at your
site, the command
info
will give you access to the complete manual.
NEWLIB April 2010 __TZ_LOCK(3)
