From:
Operating system: All
PHP version: 5.4.0
Package: *General Issues
Bug Type: Feature/Change Request
Bug description:Feature request: Shared Keyword
Description:
------------
Feature request: Shared Keyword
Declaring class properties as shared makes them accessible for all
instances of a PHP script containing the same class name and the same
property name.
This functionality allows a shared memory access similar to apc_store() and
apc_fetch().
The shared property implies the static property.
Shared propertes can be accessed without needing an instantiation of the
class.
If shared is not set for a property, it will be non-shared by default.
Shared properties are accessed through the class name or a class name
variable or "self", and the Scope Resolution Operator "::".
Like any other PHP static variable, shared properties may only be
initialized using a literal or constant; expressions are not allowed.
So while you may initialize a shared property to an integer or array (for
instance), you may not initialize it to another variable, to a function
return value, or to an object.
Shared memory limit in php.ini:
shared_memory_limit = 16M
This sets the maximum amount of shared memory in bytes that ALL scripts are
allowed to allocate.
To have no shared memory limit, set this directive to -1.
To have an unlimited shared memory limit, set this directive to 0.
When an integer is used, the value is measured in bytes. Shorthand notation
may also be used.
Shared variables and properties are initialized only in first call of a
function/class and every time the shared memory is empty.
Scenarios: Caching, performance optimization, counters, progress
indicators, parallel queues, etc.
Test script:
---------------
Foo.php: static class property
<?
class Foo
{
shared $cache_shared = "hello"; // public static shared
private shared $_cache_shared = "hello"; // private static shared
protected shared $_cache_shared = "hello"; // protected static shared
shared static $cache_static_shared = "hello"; // invalid, shared
implies static
$var1 = "hello"; // public non-static non-shared
}
Foo2.php: static variable
<?
function some_big_calc()
{
shared $a = array();
}
Scenarios:
some_class::$shared_cache = array(...);
some_class::$shared_counter++;
some_class::$shared_progress = 0.3;
--
Edit bug report at https://bugs.php.net/bug.php?id=61277&edit=1
--
Try a snapshot (PHP 5.4):
https://bugs.php.net/fix.php?id=61277&r=trysnapshot54
Try a snapshot (PHP 5.3):
https://bugs.php.net/fix.php?id=61277&r=trysnapshot53
Try a snapshot (trunk):
https://bugs.php.net/fix.php?id=61277&r=trysnapshottrunk
Fixed in SVN:
https://bugs.php.net/fix.php?id=61277&r=fixed
Fixed in SVN and need be documented:
https://bugs.php.net/fix.php?id=61277&r=needdocs
Fixed in release:
https://bugs.php.net/fix.php?id=61277&r=alreadyfixed
Need backtrace:
https://bugs.php.net/fix.php?id=61277&r=needtrace
Need Reproduce Script:
https://bugs.php.net/fix.php?id=61277&r=needscript
Try newer version:
https://bugs.php.net/fix.php?id=61277&r=oldversion
Not developer issue:
https://bugs.php.net/fix.php?id=61277&r=support
Expected behavior:
https://bugs.php.net/fix.php?id=61277&r=notwrong
Not enough info:
https://bugs.php.net/fix.php?id=61277&r=notenoughinfo
Submitted twice:
https://bugs.php.net/fix.php?id=61277&r=submittedtwice
register_globals:
https://bugs.php.net/fix.php?id=61277&r=globals
PHP 4 support discontinued:
https://bugs.php.net/fix.php?id=61277&r=php4
Daylight Savings: https://bugs.php.net/fix.php?id=61277&r=dst
IIS Stability:
https://bugs.php.net/fix.php?id=61277&r=isapi
Install GNU Sed:
https://bugs.php.net/fix.php?id=61277&r=gnused
Floating point limitations:
https://bugs.php.net/fix.php?id=61277&r=float
No Zend Extensions:
https://bugs.php.net/fix.php?id=61277&r=nozend
MySQL Configuration Error:
https://bugs.php.net/fix.php?id=61277&r=mysqlcfg
