php / php/php-src

PHP 8.4.0RC4: Zend Observer does not work for PDO query() method when the new PDO connect() is used

Aperta
#16,857 7 commenti 0 reazioni 0 assegnatari Vedi su GitHub

Nessuno ha ancora preso questa issue.

Bug Category: Documentation Extension: pdo (core) Status: Needs Triage
Lingua principale
C
Stelle
40.4k
Fork
8.1k
Merge medio
2g 13h
PR unite (30g)
96

Descrizione

Description

Problem Description
We have a custom PHP extension that registers as an observer for PDO extension's methods like __construct(), query(), etc., and our extension's handler functions get invoked when any of these PDO methods are being executed. This code is pretty generic from our side and is the same for all PDO methods we observe. But starting from PHP 8.4.0, our observer functions/function handlers are not being invoked when PDO query() method is being executed (when connect() is used) - the execution directly goes to PDO query() method instead of our registered function handlers. There is some crucial, unexplained behavioral difference I want to highlight here considering PHP introduced connect() method to create PDO objects. We adapted our code to also register observer & function handler for the new connect() method and our function handler is being invoked correctly for connect() method but not for query() method that is executed after the connect().

So:
If PDO::__construct() is used by PHP app, our extension's function handlers for __construct() AND query() are both correctly invoked by the Zend engine.
If PDO::connect() is used by PHP app, only connect() function handler in our extension is invoked but not the function handler for query().

This is inconsistent behaviour from the Zend engine.

Just to clarify how we use Zend observer API:
During MINIT:

  1. We use zend_observer_fcall_register() to register begin and end function handlers.
  2. We use the CG() macro to get class entry object for "PDO" class and overwrite the zend_function->internal_function_handler with our own function for __construct(), connect(), query()

We verified some aspects during runtime using a debugger :

  1. Looking into the CG hashtable after we register our functions - we can confirm that zend_function->internal_function_handler for both connect() and query() hold the pointers to our extension's overwritten function handler, not the original PDO methods. 2. Inside ZEND_DO_FCALL_SPEC_OBSERVER_HANDLER() in zend_vm_execute.h from where these two functions/PDO methods are eventually invoked, we can see that the fbc->internal_function.handler for during query() execution holds some unresolved address - that is neither pointing to zim_PDO_query() or our extension's overwritten function handler.

Strange thing is, for the PDO connect() execution, fbc->internal_function.handler does point to our extension's function handler. As I said, registering observer and overwriting function handlers for these functions in the CG hashtable is generic and has been working on PHP 8.3.

PHP Version

PHP 8.4.0RC4

Operating System

No response

Guida per i contributori

Apri la guida per i contributori

Come iniziare

  1. Leggi tutta la issue e poi la guida ai contributi del progetto.
  2. Commenta sulla issue per dire che te ne occupi tu — evita che due persone facciano lo stesso lavoro.
  3. Fai un fork del repository e lavora su un branch.
  4. Apri una pull request che faccia riferimento al numero della issue.

Direzione di ricerca

Riproducete la differenza tra PDO::__construct() e PDO::connect() seguito da query() utilizzando la registrazione dell’observer Zend e le sovrascritture dell’handler descritte nell’issue. Iniziate da ZEND_DO_FCALL_SPEC_OBSERVER_HANDLER() in zend_vm_execute.h e ispezionate le voci PDO nella CG hashtable; il lavoro è completato quando query() invoca costantemente l’handler dell’observer registrato dopo connect().

Scritto dal modello di indicizzazione a partire dal testo della issue.

Valutazione

Stack tecnologico
c, php
Ambito
backend, compilers
Tipo di issue
Bug
Difficoltà
4/5
Tempo stimato
3-5 giorni
Stato di attività
Ferma
Chiarezza
Abbastanza chiara
Idoneità per principianti
35/100

Ricevi le nuove issue nella tua casella

Un breve riepilogo di issue GitHub adatte ai principianti.