This feature is obsolete.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.
#include <prthread.h> typedef struct PRThreadStack PRThreadStack;
PRThreadStack structure is only used in the third argument "
PRThreadStack *stack" to the PR_AttachThread function. The '
stack' argument is now obsolete and ignored by PR_AttachThread. You should pass
NULL as the 'stack' argument to PR_AttachThread.