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.
This prohibits binding closures returned by
ReflectionMethod::getClosure() to a $this, which is not an
instance of the method scope. This restriction was already in
place for internal methods, now it is extended to user methods.
ML discussion: http://markmail.org/message/zepnhdyr3kij6di6
This opcodes inserts a local CV into the closure static variable
table. This replaces the previous mechanism of having static
variables marked as LEXICAL, which perform a symtable lookup
during copying.
This means a) functions which contain closures no longer have to
rebuild their symtable (better performance) and b) we can now track
used variables in SSA.
Move all rebinding checks into one function to make sure they stay
in sync. Normalize return value to be NULL for all rebinding
failures, instead of returning an improperly bound closure in some
cases.
As it turns out, there is actually no reason to prevent this, it even was a bigger BC break than expected...
Also fixes a memory leak (the Closure leaks) when calling internal functions via Closure by moving it out of leave helper onto caller side for TOP_CODE:
$z = new SplStack; $z->push(20);
$x = (new ReflectionMethod("SplStack", "pop"))->getClosure($z);
var_dump($x());
Now it is completely impossible to rebind a scoped method Closure (only the kind you get from ReflectionMethod::getClosure()) to a foreign scope
Adding a lot of tests to ensure this...
Also, properly return NULL in case the Closure could not be created instead of some crippled unbound Closure
This additionally removes support for binding to an unknown (not in parent hierarchy) scope.
Removing support for cross-scope is necessary for certain compile-time assumptions (like class constants) to prevent unexpected results
