Historicaly, these macros were introduced as a protection from execution timeout handling, but we don't need them anymore after "safe execution timeout" implementation.
These macros are still useful to protect from termination during inner process data modification, because of OS signals (e.g. SIGTERM during OPcache SHM update).
Instead of slow down hash_merge, we may also check the array(whether it
contains INDIRECT) outside of the loop, however, consisdering hash_merge
is not widly used, I prefer fix this in the current way to keep the
codes simple
Squashed commit of the following:
commit d96eab8d79
Author: Francois Laupretre <francois@tekwire.net>
Date: Fri Jun 26 01:23:31 2015 +0200
Use the new 'ZSTR' macros in the rest of the code.
Does not change anything to the generated code (thanks to compat macros) but cleaner.
commit b352643910
Author: Francois Laupretre <francois@tekwire.net>
Date: Thu Jun 25 13:45:06 2015 +0200
Improve zend_string API
Add missing methods
Split off zend_hash_compare_impl into separate function that does
not bother with recursion protection. We had two cases where
UNPROTECT_RECURSION was missing.
New implementation of hashtables introduced a compaction step which is
triggered when a hashtable is full but it contains at least one deleted
bucket. Therefore there is a possibility that a cleverly crafted code can
trigger this compaction step (which takes time proportional to the size of
hashtabe) by executing constatnt number of operations. When the hashtable
is full, deletion and subsequent addition or single element triggers a
table compaction and these two steps can be repeated ad infinitum. This
might be avenue for a DOS attack.
This patch allows compaction to be performed only if the hashtable contains
at least 1/32 deleted elements, otherwise the hashtable is doubled in size.
Linear amount of work caused by compaction is amortized over multiple
malicious additions and deletions.
Removed HashTable->arHash (reduced memory consumption). Now hash slots may be accessed using HT_HASH() macro.
Hash slotas are allocated together with Buckets (before them) and lay in reverse order from HashTable->arData base address (see comments in Zend/zend_types.h)
Indexes in hash table and conflict resolution chains (Z_NEXT) may be stored as indeces or offsets in bytes, depending on system (32 or 64-bit).
HashTable data filelds are reordered to keep the most useful for zend_hash_find() data in the same CPU cache line.
Now each HashTable is also zend_array, so it's refcounted and may be a subject for Copy on Write
zend_array_dup() was changed to allocate and return HashTable, instead of taking preallocated HashTable as argument.
Squashed commit of the following:
commit 1e41295097
Author: Dmitry Stogov <dmitry@zend.com>
Date: Sat Jan 31 07:28:58 2015 +0300
Generalize HashTableIterator API to allows its usage without involvement of HashTable.nInternalPonter
commit 5406f21b11
Author: Dmitry Stogov <dmitry@zend.com>
Date: Fri Jan 30 18:08:43 2015 +0300
Reduced alghorithms complexity
commit b37f1d58d2
Author: Dmitry Stogov <dmitry@zend.com>
Date: Fri Jan 30 18:08:30 2015 +0300
Fixed test name
commit fb2d079645
Author: Dmitry Stogov <dmitry@zend.com>
Date: Fri Jan 30 18:08:05 2015 +0300
API cleanup
commit 08302c0d6d
Author: Dmitry Stogov <dmitry@zend.com>
Date: Fri Jan 30 14:20:46 2015 +0300
Make array_splice() to preserve foreach hash position
commit cc4b7be41e
Author: Dmitry Stogov <dmitry@zend.com>
Date: Fri Jan 30 12:24:31 2015 +0300
Make internal function, operation on array passed by reference, to preserve foreach hash position
commit 5aa9712b0a
Author: Dmitry Stogov <dmitry@zend.com>
Date: Fri Jan 30 09:49:35 2015 +0300
Implement consistent behavior for foreach by value over plain object
commit 4c5b385ff5
Author: Dmitry Stogov <dmitry@zend.com>
Date: Fri Jan 30 07:56:37 2015 +0300
More careful iterators update.
commit 721fc9e80d
Author: Dmitry Stogov <dmitry@zend.com>
Date: Thu Jan 29 21:43:28 2015 +0300
Added new test
commit 15a23b1218
Author: Dmitry Stogov <dmitry@zend.com>
Date: Thu Jan 29 21:05:02 2015 +0300
Reimplement iteration magic with HashTableIterators (see https://wiki.php.net/rfc/php7_foreach#implementation_details)
commit 10a3260b1f
Author: Dmitry Stogov <dmitry@zend.com>
Date: Thu Jan 29 21:04:44 2015 +0300
New test
commit eef80c5837
Author: Dmitry Stogov <dmitry@zend.com>
Date: Wed Jan 28 16:52:21 2015 +0300
Fixed foreach by reference iteration over constant array
commit 61e7391873
Author: Dmitry Stogov <dmitry@zend.com>
Date: Wed Jan 28 14:59:54 2015 +0300
Fixed temporary variable re-allocation pass
commit 92e90c09f0
Author: Dmitry Stogov <dmitry@zend.com>
Date: Wed Jan 28 12:44:57 2015 +0300
Fixed operand destruction in case of exceptions in iterator
commit dd2a36a207
Author: Dmitry Stogov <dmitry@zend.com>
Date: Wed Jan 28 10:02:34 2015 +0300
Use GET_OP1_ZVAL_PTR_DEREF() (IS_TMP_VAR and IS_CONST can't be IS_REFERENCE)
commit 4638f7b914
Author: Dmitry Stogov <dmitry@zend.com>
Date: Wed Jan 28 07:43:28 2015 +0300
Change "foreach" statement behavior (this is just a PoC yet)
- "foreach by value" don't relay on internal array/object pointer and doesnt perform array duplication. It just locks it incrementing reference counter. If the original array is modified by some code, the copy on write is performed and "foreach" still work with the old copy.
- it makes no difference if array given to "foreach by value" is reference itself
- "foreach by reference" still use internal array/object pointer and should work similar to PHP-5. (This id not completely implemented)
Make nTableMask to be 0 for packed arrays.
Remove checks fo HASH_FLAG_PACKED in zend_hash_find/zend_hash_del and family (string keys are resolved through uninitialized_bucket).
Change HashTable layout for better locality.
