# PRThreadStack :::{container} blockIndicator obsolete obsoleteHeader **Obsolete** This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it. ::: The opaque {ref}`PRThreadStack` structure is only used in the third argument "`PRThreadStack *stack`" to the {ref}`PR_AttachThread` function. The '`stack`' argument is now obsolete and ignored by {ref}`PR_AttachThread`. You should pass `NULL` as the 'stack' argument to {ref}`PR_AttachThread`. (definition)= ## Syntax ```{code} #include typedef struct PRThreadStack PRThreadStack; ``` (definition-2)= -