com php-src: document globals accesor macro and tls specifiers: UPGRADING.INTERNALS

Commit: f6d196a38f484603452ca0ffaa241940c452ac99 Author: Anatol Belski <ab@php.net> Wed, 29 Jul 2015 17:26:05 +0200 Parents: 859507c9aff83a9bb1b8e968ad709841f4dc1bef Branches: master Link: http://git.php.net/?p=php-src.git;a=commitdiff;h=f6d196a38f484603452ca0ffaa241940c452ac99 Log: document globals accesor macro and tls specifiers Changed paths: M UPGRADING.INTERNALS Diff: diff --git a/UPGRADING.INTERNALS b/UPGRADING.INTERNALS index ce97cba..d0bcafb 100644 --- a/UPGRADING.INTERNALS +++ b/UPGRADING.INTERNALS @@ -194,6 +194,26 @@ changes. See: https://wiki.php.net/phpng-upgrading into the destructor. So the previous example could look like free(my_struct->vars); given the income was casted to (struct my_struct *). + A new macro was introduced to simplify the declaration to the extension + globals. A simplified declaration looks as follows + + #define MYEXT_G(v) ZEND_MODULE_GLOBALS_ACCESSOR(myext, v) + + Two new storage specifiers was introduced. + + ZEND_EXT_TLS - expand to an appropriate thread specific storage specifier in + the thread safe build, expands to empty in a non thread safe + build. + ZEND_TLS - expands to an appropriate thread specific storage specifier + with static visibility in the thread safe build, expands to + an empty string in a non thread safe build. + + Variables declared with these storage specifiers can not be shared across + threads. While ZEND_TLS enforces the local scope visibility, ZEND_EXT_TLS + pertains to the visiblity across several compilation units. In both cases, + there's no portable way to achieve the visibility across shared objects. + Thus, these specifiers are not compatible with ZEND_API and PHPAPI specifiers. + q. gc_collect_cycles() is now a function pointer, and can be replaced in the same manner as zend_execute_ex() if needed (for example, to include the time spent in the garbage collector in a profiler). The default