@node POSIX Threads
@c @node POSIX Threads, , Cryptographic Functions, Top
@chapter POSIX Threads
@c %MENU% POSIX Threads
@cindex threads

This chapter describes the @glibcadj{} POSIX Thread implementation.

@menu
* Thread-specific Data::          Support for creating and
				  managing thread-specific data
@end menu

@node Thread-specific Data
@section Thread-specific Data

The @glibcadj{} implements functions to allow users to create and manage
data specific to a thread.  Such data may be destroyed at thread exit,
if a destructor is provided.  The following functions are defined:

@table @code

@item int pthread_key_create (pthread_key_t *@var{key}, void (*@var{destructor})(void*))
Create a thread-specific data key for the calling thread, referenced by
@var{key}.

Objects declared with the C++11 @code{thread_local} keyword are destroyed
before thread-specific data, so they should not be used in thread-specific
data destructors or even as members of the thread-specific data, since the
latter is passed as an argument to the destructor function.

@item int pthread_key_delete (pthread_key_t @var{key})
Destroy the thread-specific data @var{key} in the calling thread.  The
destructor for the thread-specific data is not called during destruction, nor
is it called during thread exit.

@item void *pthread_getspecific (pthread_key_t @var{key})
Return the thread-specific data associated with @var{key} in the calling
thread.

@item int pthread_setspecific (pthread_key_t @var{key}, const void *@var{value})
Associate the thread-specific @var{value} with @var{key} in the calling thread.

@end table