You might run into a situation in which you need write access to a
parameter that's retrieved with zend_get_parameters_ex() but not passed by reference. For this case, you can use the macro
SEPARATE_ZVAL, which does a zval separation on the provided
container. The newly generated zval is detached from internal
data and has only a local scope, meaning that it can be changed or destroyed
without implying global changes in the script context:
zval **parameter;
/* retrieve parameter */
zend_get_parameters_ex(1, ¶meter);
/* at this stage, <parameter> still is connected */
/* to Zend's internal data buffers */
/* make <parameter> write-safe */
SEPARATE_ZVAL(parameter);
/* now we can safely modify <parameter> */
/* without implying global changes */ |
SEPARATE_ZVAL uses
emalloc()
to allocate the new
zval container, which means that even if you
don't deallocate this memory yourself, it will be destroyed automatically upon
script termination. However, doing a lot of calls to this macro
without freeing the resulting containers will clutter up your RAM.
Note: As you can easily work around the lack of write access in the "traditional" API
(with zend_get_parameters() and so on), this API seems to be obsolete, and is not discussed further in this chapter.
