pthread_exit(3)

1pthread_exit(3)            Library Functions Manual            pthread_exit(3)
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NAME

6       pthread_exit - terminate calling thread
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LIBRARY

9       POSIX threads library (libpthread, -lpthread)
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SYNOPSIS

12       #include <pthread.h>
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14       [[noreturn]] void pthread_exit(void *retval);
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DESCRIPTION

17       The pthread_exit() function terminates the calling thread and returns a
18       value via retval that (if the thread is joinable) is available  to  an‐
19       other thread in the same process that calls pthread_join(3).
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21       Any  clean-up handlers established by pthread_cleanup_push(3) that have
22       not yet been popped, are popped (in the reverse of the order  in  which
23       they  were pushed) and executed.  If the thread has any thread-specific
24       data, then, after the clean-up handlers have been executed, the  corre‐
25       sponding destructor functions are called, in an unspecified order.
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27       When a thread terminates, process-shared resources (e.g., mutexes, con‐
28       dition variables, semaphores, and file descriptors) are  not  released,
29       and functions registered using atexit(3) are not called.
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31       After  the  last thread in a process terminates, the process terminates
32       as by calling exit(3) with an exit status of zero; thus, process-shared
33       resources  are  released  and  functions registered using atexit(3) are
34       called.
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RETURN VALUE

37       This function does not return to the caller.
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ERRORS

40       This function always succeeds.
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ATTRIBUTES

43       For an  explanation  of  the  terms  used  in  this  section,  see  at‐
44       tributes(7).
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46       ┌────────────────────────────────────────────┬───────────────┬─────────┐
47       │Interface                                   │ Attribute     │ Value   │
48       ├────────────────────────────────────────────┼───────────────┼─────────┤
49       │pthread_exit()                              │ Thread safety │ MT-Safe │
50       └────────────────────────────────────────────┴───────────────┴─────────┘
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STANDARDS

53       POSIX.1-2008.
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HISTORY

56       POSIX.1-2001.
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NOTES

59       Performing  a  return  from the start function of any thread other than
60       the main thread results in an implicit call  to  pthread_exit(),  using
61       the function's return value as the thread's exit status.
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63       To  allow  other  threads to continue execution, the main thread should
64       terminate by calling pthread_exit() rather than exit(3).
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66       The value pointed to by retval should not be  located  on  the  calling
67       thread's  stack,  since  the contents of that stack are undefined after
68       the thread terminates.
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BUGS

71       Currently, there are limitations in the kernel implementation logic for
72       wait(2)ing  on  a stopped thread group with a dead thread group leader.
73       This can manifest in problems such as a locked terminal if a stop  sig‐
74       nal  is  sent to a foreground process whose thread group leader has al‐
75       ready called pthread_exit().
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