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

6       pthread_mutex_init,  pthread_mutex_destroy  -  initialize  or destroy a
7       mutex
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SYNOPSIS

10       cc -mt [ flag... ] file... -lpthread [ library... ]
11       #include <pthread.h>
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13       int pthread_mutex_init(pthread_mutex_t *restrict mutex,
14            const pthread_mutexattr_t *restrict attr);
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17       int pthread_mutex_destroy(pthread_mutex_t *mutex);
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20       pthread_mutex_t mutex= PTHREAD_MUTEX_INITIALIZER;
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DESCRIPTION

24       The pthread_mutex_init() function initializes the mutex  referenced  by
25       mutex  with attributes specified by attr. If attr is  NULL, the default
26       mutex attributes are used; the  effect  is  the  same  as  passing  the
27       address  of a default mutex attributes object. Upon successful initial‐
28       ization, the state of the mutex becomes initialized and unlocked.
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31       Except for robust mutexes, attempting to initialize an already initial‐
32       ized mutex results in undefined behavior.
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35       The  pthread_mutex_destroy()  function destroys the mutex object refer‐
36       enced by mutex; the mutex object becomes, in effect,  uninitialized.  A
37       destroyed     mutex     object     can    be    re-initialized    using
38       pthread_mutex_init(); the results of otherwise referencing  the  object
39       after it has been destroyed are undefined.
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42       It is safe to destroy an initialized mutex that is unlocked. Attempting
43       to destroy a locked mutex results in undefined behavior.
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46       In cases where default mutex  attributes  are  appropriate,  the  macro
47       PTHREAD_MUTEX_INITIALIZER  can  be  used to initialize mutexes that are
48       statically allocated. The effect is equivalent to  dynamic  initializa‐
49       tion by a call to pthread_mutex_init() with parameter attr specified as
50       NULL, except that no error checks are performed.
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RETURN VALUES

53       If successful,  the  pthread_mutex_init()  and  pthread_mutex_destroy()
54       functions return  0. Otherwise, an error number is returned to indicate
55       the error.
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ERRORS

58       The pthread_mutex_init() function will fail if:
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60       EAGAIN    The system lacked the necessary resources (other than memory)
61                 to initialize another mutex.
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64       EBUSY     An attempt was detected to  re-initialize a robust mutex pre‐
65                 viously initialized but not yet destroyed. See pthread_mutex‐
66                 attr_setrobust(3C).
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69       EINVAL    An  attempt was detected to re-initialize a robust mutex pre‐
70                 viously initialized with a different set of  attributes.  See
71                 pthread_mutexattr_setrobust(3C).
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74       ENOMEM    Insufficient memory exists to initialize the mutex.
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77       EPERM     The  caller does not have the privilege to perform the opera‐
78                 tion.
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82       The pthread_mutex_init() function may fail if:
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84       EBUSY     An attempt was detected to re-initialize  the  object  refer‐
85                 enced  by  mutex,  a mutex previously initialized but not yet
86                 destroyed.
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89       EINVAL    The value specified by attr or mutex is invalid.
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93       The pthread_mutex_destroy() function may fail if:
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95       EBUSY     An attempt was detected to destroy the object  referenced  by
96                 mutex  while  it  is locked or referenced (for example, while
97                 being used in a pthread_cond_wait(3C) or  pthread_cond_timed‐
98                 wait(3C)) by another thread.
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101       EINVAL    The value specified by mutex is invalid.
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ATTRIBUTES

105       See attributes(5) for descriptions of the following attributes:
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110       ┌─────────────────────────────┬─────────────────────────────┐
111       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
112       ├─────────────────────────────┼─────────────────────────────┤
113       │Interface Stability          │Standard                     │
114       ├─────────────────────────────┼─────────────────────────────┤
115       │MT-Level                     │MT-Safe                      │
116       └─────────────────────────────┴─────────────────────────────┘
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SEE ALSO

119       pthread_cond_wait(3C),  pthread_mutex_lock(3C),  pthread_mutexattr_set‐
120       prioceiling(3C),   pthread_mutexattr_setprotocol(3C),    pthread_mutex‐
121       attr_setpshared(3C),   pthread_mutexattr_setrobust(3C),  pthread_mutex‐
122       attr_settype(3C), attributes(5), mutex(5), standards(5)
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126SunOS 5.11                        11 Nov 2008           pthread_mutex_init(3C)