Add tests for destructors behaviour with GC

Zend/tests/gc_048.phpt

@@ -0,0 +1,58 @@
+--TEST--
+GC 048: Objects with destructor are collected without delay
+--FILE--
+<?php
+
+class CycleWithoutDestructor
+{
+    private \stdClass $cycleRef;
+
+    public function __construct()
+    {
+        $this->cycleRef = new \stdClass();
+        $this->cycleRef->x = $this;
+    }
+}
+
+class CycleWithDestructor extends CycleWithoutDestructor
+{
+    public function __construct()
+    {
+        parent::__construct();
+    }
+
+    public function __destruct()
+    {
+        new CycleWithoutDestructor();
+    }
+}
+
+echo "---\n";
+
+$cycleWithoutDestructor = new CycleWithoutDestructor();
+$cycleWithoutDestructorWeak = \WeakReference::create($cycleWithoutDestructor);
+$cycleWithDestructor = new CycleWithDestructor();
+$cycleWithDestructorWeak = \WeakReference::create($cycleWithDestructor);
+gc_collect_cycles();
+
+echo "---\n";
+
+unset($cycleWithoutDestructor);
+var_dump($cycleWithoutDestructorWeak->get() !== null);
+gc_collect_cycles();
+var_dump($cycleWithoutDestructorWeak->get() !== null);
+
+echo "---\n";
+
+unset($cycleWithDestructor);
+var_dump($cycleWithDestructorWeak->get() !== null);
+gc_collect_cycles();
+var_dump($cycleWithDestructorWeak->get() !== null);
+--EXPECT--
+---
+---
+bool(true)
+bool(false)
+---
+bool(true)
+bool(false)

Zend/tests/gc_049.phpt

@@ -0,0 +1,68 @@
+--TEST--
+GC 049: Objects created during GC do not participate in the same collection
+--FILE--
+<?php
+
+class CycleWithDestructor
+{
+    private \Closure $destructorFx;
+
+    private \stdClass $cycleRef;
+
+    public function __construct(\Closure $destructorFx)
+    {
+        $this->destructorFx = $destructorFx;
+        $this->cycleRef = new \stdClass();
+        $this->cycleRef->x = $this;
+    }
+
+    public function __destruct()
+    {
+        ($this->destructorFx)();
+    }
+}
+
+$isSecondGcRerun = false; // https://github.com/php/php-src/commit/b58d74547f
+$createFx = static function () use (&$createFx, &$isSecondGcRerun): void {
+    $destructorFx = static function () use (&$createFx, &$isSecondGcRerun): void {
+        if (!gc_status()['running']) {
+            echo "gc shutdown\n";
+            return;
+        }
+
+        echo "gc" . ($isSecondGcRerun ? ' rerun' : '') . "\n";
+
+        $isSecondGcRerun = !$isSecondGcRerun;
+
+        $createFx();
+    };
+
+    new CycleWithDestructor($destructorFx);
+};
+
+$createFx();
+gc_collect_cycles();
+gc_collect_cycles();
+gc_collect_cycles();
+echo "---\n";
+gc_collect_cycles();
+gc_collect_cycles();
+gc_collect_cycles();
+echo "---\n";
+?>
+--EXPECT--
+gc
+gc rerun
+gc
+gc rerun
+gc
+gc rerun
+---
+gc
+gc rerun
+gc
+gc rerun
+gc
+gc rerun
+---
+gc shutdown

Zend/tests/gc_050.phpt

@@ -0,0 +1,37 @@
+--TEST--
+GC 050: Destructor are never called twice
+--FILE--
+<?php
+
+class G
+{
+    public static $v;
+}
+
+class WithDestructor
+{
+    public function __destruct()
+    {
+        echo "d\n";
+
+        G::$v = $this;
+    }
+}
+
+$o = new WithDestructor();
+$weakO = \WeakReference::create($o);
+echo "---\n";
+unset($o);
+echo "---\n";
+var_dump($weakO->get() !== null); // verify if kept allocated
+G::$v = null;
+echo "---\n";
+var_dump($weakO->get() !== null); // verify if released
+?>
+--EXPECT--
+---
+d
+---
+bool(true)
+---
+bool(false)