pthread_exit(3p) — Linux manual page

PTHREAD_EXIT(3P)        POSIX Programmer's Manual       PTHREAD_EXIT(3P)

PROLOG

       This manual page is part of the POSIX Programmer's Manual.  The
       Linux implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior),
       or the interface may not be implemented on Linux.

NAME

       pthread_exit — thread termination

SYNOPSIS

       #include <pthread.h>

       void pthread_exit(void *value_ptr);

DESCRIPTION

       The pthread_exit() function shall terminate the calling thread
       and make the value value_ptr available to any successful join
       with the terminating thread. Any cancellation cleanup handlers
       that have been pushed and not yet popped shall be popped in the
       reverse order that they were pushed and then executed. After all
       cancellation cleanup handlers have been executed, if the thread
       has any thread-specific data, appropriate destructor functions
       shall be called in an unspecified order. Thread termination does
       not release any application visible process resources, including,
       but not limited to, mutexes and file descriptors, nor does it
       perform any process-level cleanup actions, including, but not
       limited to, calling any atexit() routines that may exist.

       An implicit call to pthread_exit() is made when a thread other
       than the thread in which main() was first invoked returns from
       the start routine that was used to create it. The function's
       return value shall serve as the thread's exit status.

       The behavior of pthread_exit() is undefined if called from a
       cancellation cleanup handler or destructor function that was
       invoked as a result of either an implicit or explicit call to
       pthread_exit().

       After a thread has terminated, the result of access to local
       (auto) variables of the thread is undefined. Thus, references to
       local variables of the exiting thread should not be used for the
       pthread_exit() value_ptr parameter value.

       The process shall exit with an exit status of 0 after the last
       thread has been terminated. The behavior shall be as if the
       implementation called exit() with a zero argument at thread
       termination time.

RETURN VALUE

       The pthread_exit() function cannot return to its caller.

ERRORS

       No errors are defined.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       The normal mechanism by which a thread terminates is to return
       from the routine that was specified in the pthread_create() call
       that started it. The pthread_exit() function provides the
       capability for a thread to terminate without requiring a return
       from the start routine of that thread, thereby providing a
       function analogous to exit().

       Regardless of the method of thread termination, any cancellation
       cleanup handlers that have been pushed and not yet popped are
       executed, and the destructors for any existing thread-specific
       data are executed. This volume of POSIX.1‐2017 requires that
       cancellation cleanup handlers be popped and called in order.
       After all cancellation cleanup handlers have been executed,
       thread-specific data destructors are called, in an unspecified
       order, for each item of thread-specific data that exists in the
       thread. This ordering is necessary because cancellation cleanup
       handlers may rely on thread-specific data.

       As the meaning of the status is determined by the application
       (except when the thread has been canceled, in which case it is
       PTHREAD_CANCELED), the implementation has no idea what an illegal
       status value is, which is why no address error checking is done.

FUTURE DIRECTIONS

       None.

SEE ALSO

       exit(3p), pthread_create(3p), pthread_join(3p)

       The Base Definitions volume of POSIX.1‐2017, pthread.h(0p)

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 by the Institute of Electrical and Electronics
       Engineers, Inc and The Open Group.  In the event of any
       discrepancy between this version and the original IEEE and The
       Open Group Standard, the original IEEE and The Open Group
       Standard is the referee document. The original Standard can be
       obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page
       are most likely to have been introduced during the conversion of
       the source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group               2017                  PTHREAD_EXIT(3P)

Pages that refer to this page: pthread.h(0p), pthread_cancel(3p), pthread_create(3p)

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