Without these zend_trys we may
a) leak the object (fine)
b) don't add it to the free list (also fine, we just lose an
object store bucket)
c) don't remove it from the GC root buffer (also fine, because GC
explicitly checks for both FREE_CALLED and invalid buckets)
Corrupted class entries on shutdown when a destructor spawns another object
(C) 2017 CommerceByte Consulting
When zend_objects_store_call_destructors() is called from the shutdown sequence -
it's calling the dtor's for remaining objects one by one in sequence of object handles.
If the dtor spawns one or more objects, and the new objects happen to reuse the old handles -
their dtor's are not called in this cycle.
The dtor's are called later on, when zend_deactivete() kicks in, and the static property lists in the class entries are freed.
This causes "Undefined static property" errors, and/or SIGSEGV.
Solution:
zend_object_store.no_reuse field is added
Set to 0 on initialization, set to 1 on the shutdown sequence.
zend_objects_store_put(zend_object *) checks the no_reuse flag, and never reuses the old handle slots if set.
This way, the dtor's for newly spawned objects are guaranteed to be called in the zend_objects_store_call_destructors() loop.
Cycle leaks are currently not reported, because this needs further
work.
The last GC run has been moved to run earlier (before the object
store free), so that array cycles that hold references to objects
don't show up as leaks. Fingers crossed that this doesn't adversely
affect anything else.
It should be accessed using Z_CACHE_SLOT() macro.
zend_literal structure is removed.
API functions that accepted pointer to zend_literal now accept pointer to zval or cache_slot directly.
Calls of such functiond that now accept cache_slot need to be changed to pass -1 instead of NULL.
Nikita Popov