pthread_spin_destroy(3p)

1PTHREAD_SPIN_DESTROY(3P)   POSIX Programmer's Manual  PTHREAD_SPIN_DESTROY(3P)
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PROLOG

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

12       pthread_spin_destroy, pthread_spin_init — destroy or initialize a  spin
13       lock object
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SYNOPSIS

16       #include <pthread.h>
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18       int pthread_spin_destroy(pthread_spinlock_t *lock);
19       int pthread_spin_init(pthread_spinlock_t *lock, int pshared);
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DESCRIPTION

22       The  pthread_spin_destroy() function shall destroy the spin lock refer‐
23       enced by lock and release any resources used by the lock. The effect of
24       subsequent use of the lock is undefined until the lock is reinitialized
25       by another call to pthread_spin_init().  The results are  undefined  if
26       pthread_spin_destroy()  is  called  when a thread holds the lock, or if
27       this function is called with an uninitialized thread spin lock.
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29       The pthread_spin_init() function shall allocate any resources  required
30       to  use  the spin lock referenced by lock and initialize the lock to an
31       unlocked state.
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33       If the Thread Process-Shared Synchronization option  is  supported  and
34       the  value  of  pshared  is  PTHREAD_PROCESS_SHARED, the implementation
35       shall permit the spin lock to be operated upon by any thread  that  has
36       access  to  the  memory where the spin lock is allocated, even if it is
37       allocated in memory that is shared by multiple processes.
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39       See Section 2.9.9, Synchronization Object Copies and  Alternative  Map‐
40       pings for further requirements.
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42       The  results  are undefined if pthread_spin_init() is called specifying
43       an already initialized spin lock. The results are undefined if  a  spin
44       lock is used without first being initialized.
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46       If  the pthread_spin_init() function fails, the lock is not initialized
47       and the contents of lock are undefined.
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49       Only the object referenced by lock may be used for performing  synchro‐
50       nization.
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52       The  result  of  referring  to  copies  of  that  object  in  calls  to
53       pthread_spin_destroy(), pthread_spin_lock(), pthread_spin_trylock(), or
54       pthread_spin_unlock() is undefined.
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RETURN VALUE

57       Upon  successful  completion, these functions shall return zero; other‐
58       wise, an error number shall be returned to indicate the error.
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ERRORS

61       The pthread_spin_init() function shall fail if:
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63       EAGAIN The system lacks the necessary resources to  initialize  another
64              spin lock.
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66       ENOMEM Insufficient memory exists to initialize the lock.
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68       These functions shall not return an error code of [EINTR].
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70       The following sections are informative.
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EXAMPLES

73       None.
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APPLICATION USAGE

76       None.
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RATIONALE

79       If an implementation detects that the value specified by the lock argu‐
80       ment to pthread_spin_destroy() does not refer to  an  initialized  spin
81       lock object, it is recommended that the function should fail and report
82       an [EINVAL] error.
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84       If an implementation detects that the value specified by the lock argu‐
85       ment  to  pthread_spin_destroy()  or  pthread_spin_init()  refers  to a
86       locked spin lock object, or detects that the  value  specified  by  the
87       lock  argument  to pthread_spin_init() refers to an already initialized
88       spin lock object, it is recommended that the function should  fail  and
89       report an [EBUSY] error.
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FUTURE DIRECTIONS

92       None.
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COPYRIGHT

100       Portions  of  this text are reprinted and reproduced in electronic form
101       from IEEE Std 1003.1-2017, Standard for Information Technology --  Por‐
102       table  Operating System Interface (POSIX), The Open Group Base Specifi‐
103       cations Issue 7, 2018 Edition, Copyright (C) 2018 by the  Institute  of
104       Electrical  and  Electronics Engineers, Inc and The Open Group.  In the
105       event of any discrepancy between this version and the original IEEE and
106       The  Open Group Standard, the original IEEE and The Open Group Standard
107       is the referee document. The original Standard can be  obtained  online
108       at http://www.opengroup.org/unix/online.html .
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110       Any  typographical  or  formatting  errors that appear in this page are
111       most likely to have been introduced during the conversion of the source
112       files  to  man page format. To report such errors, see https://www.ker‐
113       nel.org/doc/man-pages/reporting_bugs.html .
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117IEEE/The Open Group                  2017             PTHREAD_SPIN_DESTROY(3P)