In situations when there is single item receiving lots of values over short period and javascript preprocessing there is high memory usage in preprocessing manager because queue grows much faster than it can be processed due to javascript being executed in serial fashion.

Expected:
There is no reason to preprocess javascript serially, caching of compiled javascript in parallel can be implemented using locks (for simplicity it can be one common lock to access javascript cache because it is only used to store pointer, or lock per each preprocessing for best performance). When executing many javascripts in parallel then queue does not grow because it is processed faster then filled, thus memory usage stays low and data is preprocessed faster.

Steps:
Same as in ZBXNEXT-9622

Here is simple patch that disables caching of compiled javascript ZBX-25642-7.0.diff that can be tested to see if it resolves high memory usage