Garbage collection stops after exception in SoapClient

Description

The following code:

<?php

class A
{
	public $b;
}

class B
{
	public $a;
}

function buildCycle()
{
	$a = new A();
	$b = new B();
	$a->b = $b;
	$b->a = $a;
}

function failySoapCall()
{

	try {
		new SoapClient('https://nowhere.inexistent.space/?WSDL');
	}
	catch (Exception) {
		echo "Soap call failed\n";
	}
}

function gc()
{
	gc_collect_cycles();
	echo "GC Runs: " . gc_status()['runs'] . "\n";
}


buildCycle();
gc();
buildCycle();
gc();
buildCycle();
gc();

failySoapCall();

buildCycle();
gc();
buildCycle();
gc();
buildCycle();
gc();

Resulted in this output:

GC Runs: 1
GC Runs: 2
GC Runs: 3
Soap call failed
GC Runs: 3
GC Runs: 3
GC Runs: 3

But I expected this output instead:

GC Runs: 1
GC Runs: 2
GC Runs: 3
Soap call failed
GC Runs: 4
GC Runs: 5
GC Runs: 6

The SOAP exception apparently stops the garbage collector. I experienced this problem with a large, long running process. Its memory usage is intensive but stable. Until it encounters a SOAP exception: its memory usage skyrockets, and gc_status() reports that no more gc run is done.

PHP Version

PHP 8.1.13

Operating System

Alpine 3.16

PHP 8.1.13 および Alpine 3.16 で、提供されている PHP の再現コードを SoapClient、gc_collect_cycles()、gc_status() とともに実行します。まず、例外の経路と、循環ガベージコレクションとの相互作用を追跡します。失敗した SOAP 呼び出しの後もガベージコレクションの実行が継続し、報告されたサイクル数が期待される出力と一致すれば完了です。