man/pthread_rwlock_init.3

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  27 .Dd August 4, 1998
  28 .Dt PTHREAD_RWLOCK_INIT 3
  29 .Os
  30 .Sh NAME
  31 .Nm pthread_rwlock_init
  32 .Nd initialize a read/write lock
  33 .Sh SYNOPSIS
  34 .In pthread.h
  35 .Ft int
  36 .Fn pthread_rwlock_init "pthread_rwlock_t *lock" "const pthread_rwlockattr_t *attr"
  37 .Sh DESCRIPTION
  38 The
  39 .Fn pthread_rwlock_init
  40 function is used to initialize a read/write lock, with attributes
  41 specified by
  42 .Fa attr .
  43 If
  44 .Fa attr
  45 is NULL, the default read/write lock attributes are used.
  46 .Pp
  47 The results of calling
  48 .Fn pthread_rwlock_init
  49 with an already initialized lock are undefined.
  50 .Sh RETURN VALUES
  51 If successful, the
  52 .Fn pthread_rwlock_init
  53 function will return zero.
  54 Otherwise an error number will be returned
  55 to indicate the error.
  56 .Sh ERRORS
  57 The
  58 .Fn pthread_rwlock_init
  59 function will fail if:
  60 .Bl -tag -width Er
  61 .It Bq Er EAGAIN
  62 The system lacked the necessary resources (other than memory) to
  63 initialize the lock.
  64 .It Bq Er ENOMEM
  65 Insufficient memory exists to initialize the lock.
  66 .It Bq Er EPERM
  67 The caller does not have sufficient privilege to perform the
  68 operation.
  69 .El
  70 .Pp
  71 The
  72 .Fn pthread_rwlock_init
  73 function may fail if:
  74 .Bl -tag -width Er
  75 .It Bq Er EBUSY
  76 The system has detected an attempt to re-initialize the object
  77 referenced by
  78 .Fa lock ,
  79 a previously initialized but not yet destroyed read/write lock.
  80 .It Bq Er EINVAL
  81 The value specified by
  82 .Fa attr
  83 is invalid.
  84 .El
  85 .Sh SEE ALSO
  86 .Xr pthread_rwlock_destroy 3 ,
  87 .Xr pthread_rwlockattr_init 3 ,
  88 .Xr pthread_rwlockattr_setpshared 3
  89 .Sh STANDARDS
  90 The
  91 .Fn pthread_rwlock_init
  92 function is expected to conform to
  93 .St -susv2 .
  94 .Sh HISTORY
  95 The
  96 .Fn pthread_rwlock_init
  97 function first appeared in
  98 .Fx 3.0 .
  99 .Sh BUGS
 100 The PTHREAD_PROCESS_SHARED attribute is not supported.