Re: com php-src: fix CG(empty_string) init in ZTS: Zend/zend.c

I know :) Interned strings in PHP5 were implemented as characters allocated in one single buffer. Adding new strings into this buffer from different threads would require synchronization (locks). In PHP7 this implementation was changed. So it's probably must be possible to use interned strings in ZTS now. If we use separate HashTables for interned strings in different threads we may share some common part of predefined interned strings and have new interned strings in each thread independently. I'm not sure if it'll work well with opcache, because it substitutes interned strings handling mechanism to use shared memory. May be it'll work out of the box. BTW: I'm not interested in implementing this myself. Also, if we really like ZTS, may be PHP7 is the time to switch to native TLS and remove all these TSRMLS macros. Even if it won't allow to run ZTS on some platforms, it won't be the end of the world, because ZTS is not really widely used now. I won't be able to work on it actively, but I may provide some help. Thanks. Dmitry. On Fri, Sep 19, 2014 at 12:34 AM, Nikita Popov <nikita.ppv@gmail.com> wrote: > On Thu, Sep 18, 2014 at 5:14 PM, Anatol Belski <ab@php.net> wrote: > > > Commit: e8b497ad8eb74273f7f44ae7e515e7a5e95b50f7 > > Author: Anatol Belski <ab@php.net> Thu, 18 Sep 2014 16:45:50 > > +0200 > > Parents: f162b3f736f07ad868abec6ea8b44a91e77d4069 > > Branches: master > > > > Link: > > > wC > @ˆ¢Â›L-ôîêÑ#http://git.php.net/?p=php-src.git;a=commitdiff;h=e8b497ad8eb74273f7f44ae7e515e7a5e95b50f7 > > > > Log: > > fix CG(empty_string) init in ZTS > > > > Changed paths: > > M Zend/zend.c > > > > > > Diff: > > diff --git a/Zend/zend.c b/Zend/zend.c > > index 46719b4..6a53179 100644 > > --- a/Zend/zend.c > > +++ b/Zend/zend.c > > @@ -120,6 +120,7 @@ static HashTable *global_class_table = NULL; > > static HashTable *global_constants_table = NULL; > > static HashTable *global_auto_globals_table = NULL; > > static HashTable *global_persistent_list = NULL; > > +static zend_string *default_empty_string = NULL; > > #endif > > > > ZEND_API zend_utility_values zend_uv; > > @@ -514,6 +515,15 @@ static void > > compiler_globals_ctor(zend_compiler_globals *compiler_globals TSRMLS > > compiler_globals->static_members_table = NULL; > > } > > compiler_globals->script_encoding_list = NULL; > > + > > +#ifdef ZTS > > + compiler_globals->empty_string = zend_string_alloc(sizeof("")-1, > > 1); > > + compiler_globals->empty_string->val[0] = '\000'; > > + zend_string_hash_val(compiler_globals->empty_string); > > + compiler_globals->empty_string->gc.u.v.flags |= IS_STR_INTERNED; > > + > > + memset(compiler_globals->one_char_string, 0, > > sizeof(compiler_globals->one_char_string)); > > +#endif > > } > > /* }}} */ > > > > @@ -538,6 +548,10 @@ static void > > compiler_globals_dtor(zend_compiler_globals *compiler_globals TSRMLS > > pefree((char*)compiler_globals->script_encoding_list, 1); > > } > > compiler_globals->last_static_member = 0; > > + > > +#ifdef ZTS > > + free(compiler_globals->empty_string); > > +#endif > > } > > /* }}} */ > > > > What does this fix and how does it relate to the initialization done in > zend_interned_strings_init? > > Btw, does anyone know why we don't use interned strings in ZTS? > > Nikita >