pthreads/pthread_getspecific.3

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  33 .Dd April 4, 1996
  34 .Dt PTHREAD_GETSPECIFIC 3
  35 .Os
  36 .Sh NAME
  37 .Nm pthread_getspecific
  38 .Nd get a thread-specific data value
  39 .Sh SYNOPSIS
  40 .Fd #include <pthread.h>
  41 .Ft void *
  42 .Fo pthread_getspecific
  43 .Fa "pthread_key_t key"
  44 .Fc
  45 .Sh DESCRIPTION
  46 The
  47 .Fn pthread_getspecific
  48 function returns the value that is currently bound to the specified
  49 .Fa key ,
  50 on behalf of the calling thread.
  51 .Pp
  52 The effect of calling
  53 .Fn pthread_getspecific
  54 with a
  55 .Fa key
  56 value that was not obtained from
  57 .Fn pthread_key_create ,
  58 or after a
  59 .Fa key
  60 has been deleted with
  61 .Fn pthread_key_delete ,
  62 is undefined.
  63 .Pp
  64 .Fn pthread_getspecific
  65 may be called from a thread-specific data destructor function.
  66 .Sh RETURN VALUES
  67 The
  68 .Fn pthread_getspecific
  69 function will return the thread-specific data value associated with the given
  70 .Fa key .
  71 If no thread-specific data value is associated with
  72 .Fa key ,
  73 the value NULL is returned.
  74 .Sh ERRORS
  75 None.
  76 .Sh SEE ALSO
  77 .Xr pthread_key_create 3 ,
  78 .Xr pthread_key_delete 3 ,
  79 .Xr pthread_setspecific 3
  80 .Sh STANDARDS
  81 .Fn pthread_getspecific
  82 conforms to
  83 .St -p1003.1-96 .