1pthread_once(3C)         Standard C Library Functions         pthread_once(3C)
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NAME

6       pthread_once - initialize dynamic package
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SYNOPSIS

9       cc -mt [ flag... ] file... -lpthread [ library... ]
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11       #include <pthread.h>
12       pthread_once_t once_control = PTHREAD_ONCE_INIT;
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14       int pthread_once(pthread_once_t *once_control,
15            void (*init_routine)(void));
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DESCRIPTION

19       If  any  thread in a process with a once_control parameter makes a call
20       to pthread_once(), the first call will summon the  init_routine(),  but
21       subsequent  calls  will  not.  The  once_control  parameter  determines
22       whether the associated initialization  routine  has  been  called.  The
23       init_routine() is complete upon return of pthread_once().
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26       pthread_once()  is  not  a cancellation point; however, if the function
27       init_routine() is a cancellation point and is canceled, the  effect  on
28       once_control is the same as if pthread_once() had never been called.
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31       The constant PTHREAD_ONCE_INIT is defined in the <pthread.h> header.
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34       If once_control has automatic storage duration or is not initialized by
35       PTHREAD_ONCE_INIT, the behavior of pthread_once() is undefined.
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RETURN VALUES

38       Upon successful completion, pthread_once()  returns  0.  Otherwise,  an
39       error number is returned to indicate the error.
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ERRORS

42       EINVAL     once_control or  init_routine is NULL.
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ATTRIBUTES

46       See attributes(5) for descriptions of the following attributes:
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51       ┌─────────────────────────────┬─────────────────────────────┐
52       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
53       ├─────────────────────────────┼─────────────────────────────┤
54       │Interface Stability          │Standard                     │
55       ├─────────────────────────────┼─────────────────────────────┤
56       │MT-Level                     │MT-Safe                      │
57       └─────────────────────────────┴─────────────────────────────┘
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SEE ALSO

60       attributes(5), standards(5)
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NOTES

63       Solaris threads do not offer this functionality.
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67SunOS 5.11                        23 Mar 2005                 pthread_once(3C)
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