Hereby, interned strings are supported in thread safe PHP. The patch
implements two types of interned strings
- interning per process, strings are not freed till process end
- interning per request, strings are freed at request end
There is no runtime interning.
With Opcache, all the permanent iterned strings are copied into SHM on
startup, additional copying into SHM might happen on demand.
Historicaly, these macros were introduced as a protection from execution timeout handling, but we don't need them anymore after "safe execution timeout" implementation.
These macros are still useful to protect from termination during inner process data modification, because of OS signals (e.g. SIGTERM during OPcache SHM update).
Squashed commit of the following:
commit d96eab8d79
Author: Francois Laupretre <francois@tekwire.net>
Date: Fri Jun 26 01:23:31 2015 +0200
Use the new 'ZSTR' macros in the rest of the code.
Does not change anything to the generated code (thanks to compat macros) but cleaner.
commit b352643910
Author: Francois Laupretre <francois@tekwire.net>
Date: Thu Jun 25 13:45:06 2015 +0200
Improve zend_string API
Add missing methods
Removed HashTable->arHash (reduced memory consumption). Now hash slots may be accessed using HT_HASH() macro.
Hash slotas are allocated together with Buckets (before them) and lay in reverse order from HashTable->arData base address (see comments in Zend/zend_types.h)
Indexes in hash table and conflict resolution chains (Z_NEXT) may be stored as indeces or offsets in bytes, depending on system (32 or 64-bit).
HashTable data filelds are reordered to keep the most useful for zend_hash_find() data in the same CPU cache line.
still the NTS variant is somewhat different as it needs
zend_new_interned_string_int because the normal callbacks might
be not initialized, but at least no leaks anymore and some more
structure
