oracular (3) pthread_exit.3posix.gz

Provided by: manpages-posix-dev_2017a-2_all bug

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(), pthread_create(), pthread_join()

       The Base Definitions volume of POSIX.1‐2017, <pthread.h>


       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 .