man/pthread_setspecific.3

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  33 .Dd April 4, 1996
  34 .Dt PTHREAD_SETSPECIFIC 3
  35 .Os
  36 .Sh NAME
  37 .Nm pthread_setspecific
  38 .Nd set a thread-specific data value
  39 .Sh SYNOPSIS
  40 .In pthread.h
  41 .Ft int
  42 .Fn pthread_setspecific "pthread_key_t key" "const void *value"
  43 .Sh DESCRIPTION
  44 The
  45 .Fn pthread_setspecific
  46 function associates a thread-specific value with a
  47 .Fa key
  48 obtained via a previous call to
  49 .Fn pthread_key_create .
  50 Different threads can bind different values to the same key.
  51 These values are
  52 typically pointers to blocks of dynamically allocated memory that have been
  53 reserved for use by the calling thread.
  54 .Pp
  55 The effect of calling
  56 .Fn pthread_setspecific
  57 with a key value not obtained from
  58 .Fn pthread_key_create
  59 or after
  60 .Fa key
  61 has been deleted with
  62 .Fn pthread_key_delete
  63 is undefined.
  64 .Pp
  65 The
  66 .Fn pthread_setspecific
  67 function may be called from a thread-specific data destructor function,
  68 however this may result in lost storage or infinite loops.
  69 .Sh RETURN VALUES
  70 If successful, the
  71 .Fn pthread_setspecific
  72 function will return zero.
  73 Otherwise an error number will be returned to
  74 indicate the error.
  75 .Sh ERRORS
  76 The
  77 .Fn pthread_setspecific
  78 function will fail if:
  79 .Bl -tag -width Er
  80 .It Bq Er ENOMEM
  81 Insufficient memory exists to associate the value with the
  82 .Fa key .
  83 .It Bq Er EINVAL
  84 The
  85 .Fa key
  86 value is invalid.
  87 .El
  88 .Sh SEE ALSO
  89 .Xr pthread_getspecific 3 ,
  90 .Xr pthread_key_create 3 ,
  91 .Xr pthread_key_delete 3
  92 .Sh STANDARDS
  93 The
  94 .Fn pthread_setspecific
  95 function conforms to
  96 .St -p1003.1-96 .