- memory allocated with spprintf, or likes, outside of mysqlnd's
allocator functions should not be freed by the mysqlnd's allocator
(a wrapper around emalloc/malloc).
- memory allocated by the mysqlnd's allocator should only be freed
by it.
- add a mode to track memory usage (malloc/free)
Streams API registers every stream as resource, which lands then
in EG(regular_list), however doesn't clean that when the stream is
closed. At the end this is a para-leak. At the end of the script
all memory is cleaned, however this is a problem for long runnig
scripts that open connections. For every opened and closed connection
about 150 Bytes on 32bit and 250 Bytes on 64bit will be "lost",
according to memory_get_usage().
If the protocol gets changed, ever, we can decide at runtime
easily which protocol to use by instantiating the right protocol
object. But this is restricted to the structure of the packets, not
the flow.
