The zend_object.properties HashTable needs to be built just in time by calling
rebuild_object_properties() on the object before accessing it. Normally this is
done automatically in zend_std_get_properties(), but we do it manually in a few
places.
In this change I introduce an inline variant of zend_std_build_properties(), and
refactor these places to use it instead of calling rebuild_object_properties()
manually.
rebuild_object_properties() renamed as rebuild_object_properties_internal(), to
enforce usage of zend_std_get_properties() or zend_std_build_properties_ex().
Closes GH-14996
The php_random.h header already defines them as `PHPAPI` and they actually are
part of the public API.
Co-authored-by: Arnaud Le Blanc <arnaud.lb@gmail.com>
* random: Make Mt19937's `mode` field an enum
* random: Reorder the `php_random_status_state_mt19937` struct
Empirical testing did not show any differences in performance, but it makes
sense to me to put the `count` field (which is accessed for every invocation of
Mt19937) at the beginning of the struct, keeping it near the values from the
state array that are returned first, resulting in only a single cache line load
if only a small amount of numbers are requested.
It naturally follows to also put the `mode` field there and move the
humongous state array to the end.
* random: Remove the `MT_N` constant
`MT_N` is an awfully generic name that bleeds into every file including
`php_random.h`. As it's an implementation detail, remove it entirely to keep
`php_random.h` clean.
To prevent the state struct from diverging from the implementation, the size of
the state vector is statically verified. Furthermore there are phpt tests
verifying the Mt19937 output across a reload, revealing when the state vector
is reloaded too early or too late.
* random: Expose xoshiro256**'s seeding functions
* random: Expose pcgoneseq128xslrr64's seeding functions
* random: Expose Mt19937's seeding functions
* random: Expose CombinedLCG's seeding functions
* random: Call php_random_mt19937_seed32 to seed the global Mt19937
This avoids the function pointer indirection and improves type safety.
* random: NULL the generic seeding function
Different engines work quite differently, it is not useful to attempt to seed
them in a generic way using a 64 bit integer. As an example Mt19937 completely
ignores the upper 32 bits.
* random: Remove the `seed` member from `php_random_algo`
See the explanation in the previous commit for the reasoning. This member is
unused since the previous commit and was not consistently available even before
that (specifically for the Secure engine).
* UPGRADING.INTERNALS
* random: Remove useless cast in `php_mt_srand()`
* random: Remove `php_random_status`
Since 162e1dce98, the `php_random_status` struct
contains just a single `void*`, resulting in needless indirection when
accessing the engine state and thus decreasing readability because of the
additional non-meaningful `->state` references / the local helper variables.
There is also a small, but measurable performance benefit:
<?php
$e = new Random\Engine\Xoshiro256StarStar(0);
$r = new Random\Randomizer($e);
for ($i = 0; $i < 15; $i++)
var_dump(strlen($r->getBytes(100000000)));
goes from roughly 3.85s down to 3.60s.
The names of the `status` variables have not yet been touched to keep the diff
small. They will be renamed to the more appropriate `state` in a follow-up
cleanup commit.
* Introduce `php_random_algo_with_state`
This allows consumers of just the CSPRNG to include a much smaller header. It
also allows to verify at a glance whether a source file might use non-secure
randomness.
This commit includes the new header wherever the CSPRNG is used, possibly
replacing the inclusion of php_random.h if nothing else is used, but also
includes it in the main php_random.h header for compatibility.
Somewhat related to 45f8cfaf10,
2b30f18708, and
b14dd85dca.
As the `__construct()` implementation is engine-specific anyway, we know what
engine were dealing with and can just call the seeding function directly
instead of going through a function pointer.
This likely improves construction performance a little, but I did not measure.
Instead of returning the generated `uint64_t` and providing the size (i.e. the
number of bytes of the generated value) out-of-band via the
`last_generated_size` member of the `php_random_status` struct, the `generate`
function is now expected to return a new `php_random_result` struct containing
both the `size` and the `result`.
This has two benefits, one for the developer:
It's no longer possible to forget setting `last_generated_size` to the correct
value, because it now happens at the time of returning from the function.
and the other benefit is for performance:
The `php_random_result` struct will be returned as a register pair, thus the
`size` will be directly available without reloading it from main memory.
Checking a simplified version of `php_random_range64()` on Compiler Explorer
(“Godbolt”) with clang 17 shows a single change in the resulting assembly
showcasing the improvement (https://godbolt.org/z/G4WjdYxqx):
- add rbp, qword ptr [r14]
+ add rbp, rdx
Empirical testing confirms a measurable performance increase for the
`Randomizer::getBytes()` method:
<?php
$e = new Random\Engine\Xoshiro256StarStar(0);
$r = new Random\Randomizer($e);
var_dump(strlen($r->getBytes(100000000)));
goes from 250ms (before the change) to 220ms (after the change). While
generating 100 MB of random data certainly is not the most common use case, it
confirms the theoretical improvement in practice.
* Fix pre-PHP 8.2 compatibility for php_mt_rand_range() with MT_RAND_PHP
As some left-over comments indicated:
> Legacy mode deliberately not inside php_mt_rand_range()
> to prevent other functions being affected
The broken scaler was only used for `php_mt_rand_common()`, not
`php_mt_rand_range()`. The former is only used for `mt_rand()`, whereas the
latter is used for `array_rand()` and others.
With the refactoring for the introduction of ext/random `php_mt_rand_common()`
and `php_mt_rand_range()` were accidentally unified, thus introducing a
behavioral change that was reported in FakerPHP/Faker#528.
This commit moves the checks for `MT_RAND_PHP` from the general-purpose
`range()` function back into `php_mt_rand_common()` and also into
`Randomizer::getInt()` for drop-in compatibility with `mt_rand()`.
* [ci skip] NEWS for `MT_RAND_PHP` compatibility
* Apply `var_dump()` in 02_engine/all_serialize_error.phpt
This ensures that an undetected serialization error is clear identifiable in the output.
* random: Validate that the arrays do not contain extra elements when unserializing
* Emit deprecation warnings when adding dynamic properties to classes during unserialization - this will become an Error in php 9.0.
(Adding dynamic properties in other contexts was already a deprecation warning - the use case of unserialization was overlooked)
* Throw an error when attempting to add a dynamic property to a `readonly` class when unserializing
* Add new serialization methods `__serialize`/`__unserialize` for SplFixedArray to avoid creating deprecated dynamic
properties that would then be added to the backing fixed-size array
* Don't add named dynamic/declared properties (e.g. $obj->foo) of SplFixedArray to the backing array when unserializing
* Update tests to declare properties or to expect the deprecation warning
* Add news entry
Co-authored-by: Tyson Andre <tysonandre775@hotmail.com>
RAND_RANGE_BADSCALING() invokes undefined behavior when (max - min) >
ZEND_LONG_MAX, because the intermediate `double` might not fit into
`zend_long`.
Fix this by inlining a fixed version of the macro into Mt19937's range()
function. Fixing the macro itself cannot be done in the general case, because
the types of the inputs are not known. Instead of replacing one possibly broken
version with another possibly broken version, the macro is simply left as is
and should be removed in a future version.
The fix itself is simple: Instead of storing the "offset" in a `zend_long`, we
use a `zend_ulong` which is capable of storing the resulting double by
construction. With this fix the implementation of this broken scaling is
effectively identical to the implementation of php_random_range from a data
type perspective, making it easy to verify the correctness.
It was further empirically verified that the broken macro and the fix return
the same results for all possible values of `r` for several distinct pairs of
(min, max).
Fixes GH-9190
Fixes GH-9191
* Add Random\Random{Error,Exception} and Random\BrokenRandomEngineError
* Throw BrokenRandomEngineError
* Throw RandomException on seeding failure
* Throw RandomException when CSPRNG fails
* Remove unused include from ext/random/engine_combinedlcg.c
* Remove unused include from ext/random/engine_secure.c
* Remove unused include from ext/random/random.c
* [ci skip] Add ext/random Exception hierarchy to NEWS
* [ci skip] Add the change of Exception for random_(int|bytes) to UPGRADING
* Remove exception in Randomizer::shuffleBytes()
The only way that `php_binary_string_shuffle` fails is when the engine itself
fails. With the currently available list of engines we have:
- Mt19937 : Infallible.
- PcgOneseq128XslRr64: Infallible.
- Xoshiro256StarStar : Infallible.
- Secure : Practically infallible on modern systems.
Exception messages were cleaned up in GH-9169.
- User : Error when returning an empty string.
Error when seriously biased (range() fails).
And whatever Throwable the userland developer decides to use.
So the existing engines are either infallible or throw an Exception/Error with
a high quality message themselves, making this exception not a value-add and
possibly confusing.
* Remove exception in Randomizer::shuffleArray()
Same reasoning as in the previous commit applies.
* Remove exception in Randomizer::getInt()
Same reasoning as in the previous commit applies.
* Remove exception in Randomizer::nextInt()
Same reasoning as in the previous commit applies, except that it won't throw on
a seriously biased user engine, as `range()` is not used.
* Remove exception in Randomizer::getBytes()
Same reasoning as in the previous commit applies.
* Remove exception in Mt19937::generate()
This implementation is shared across all native engines. Thus the same
reasoning as the previous commits applies, except that the User engine does not
use this method. Thus is only applicable to the Secure engine, which is the
only fallible native engine.
* [ci skip] Add cleanup of Randomizer exceptions to NEWS
* Unify ext/random unserialize errors with ext/date
- Use `Error` instead of `Exception`.
- Adjust wording.
* Make `zend_read_property` silent in `Randomizer::__unserialize()`
Having:
> Error: Typed property Random\Randomizer::$engine must not be accessed before
> initialization
is not a value-add in this case.
* Insert the actual class name in the unserialization error of Engines
* Revert unserialization failure back to Exception from Error
see https://news-web.php.net/php.internals/118311
Whenever ->last_unsafe is set to `true` an exception has been thrown. Thus we
can replace the check for `->last_unsafe` with a check for `EG(exception)`
which is a much more natural way to ommunicate an error up the chain.
