TSRMLS_D/C persistence

How long are the TSRMLS_D/C parameters good for? Can the resultant tsrm_ls value be safely stored? I presume the answer is no, and these paramters should be passed in each time a function is called, but I would be curious to know differently, if for example it could be passed in once at (external object) creation time, and that object could use the trsm_ls directly, rather than the TSRMLS_D/C semantics. ... Otherwise it seems clear that an external object outside php cannot use php semantics, so cannot use the php_stream wrappers. ... That being the case, an external object (referenced from within eg: a php extension) must either: a. be able to ignore php-streams and use system streams directly (not obviously apparent, given errors experienced to date) or b. cannot use system streams when calls originate from php/extensions, (in which case no 3rd party objects which access streams are reliable in php/extensions) Clearly a. is more desirable than b. , despite the fact that an apparently reliable 3rd party object did generate errors when called from within a php-extension. --- This is my third attempt to ask for a clear answer as to whether a. or b. is correct, so hopefully someone will notice, has the answer, and can respond. Cheers, Andrew.