bug #45073 [HttpClient] Fix Failed to open stream: Too many open file…

…s (adrienfr)

This PR was merged into the 4.4 branch.

Discussion
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[HttpClient] Fix Failed to open stream: Too many open files

| Q             | A
| ------------- | ---
| Branch?       | 4.4
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Tickets       | Fix #44900
| License       | MIT

With a large PHPUnit tests suite, I receive this error "Failed to open stream: Too many open files".
I found the original code from `@nicolas`-grekas [here](https://github.com/symfony/symfony/pull/30413/files#diff-bbfff9335ca4f0716566920d7f427036c2d6f9ac2a9cb33e2c83514423ab4b14R77) and with small adjustments, it resolves my issue.

Warning: tests for HttpClient are OK but would someone try with a real HTTP/2 client push? I was not able to test it.

Commits
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40d22b8 [HttpClient] Fix Failed to open stream: Too many open files

src/Symfony/Component/HttpClient/Internal/CurlClientState.php

@@ -23,9 +23,9 @@
  */
 final class CurlClientState extends ClientState
 {
-    /** @var \CurlMultiHandle|resource */
+    /** @var \CurlMultiHandle|resource|null */
     public $handle;
-    /** @var \CurlShareHandle|resource */
+    /** @var \CurlShareHandle|resource|null */
     public $share;
     /** @var PushedResponse[] */
     public $pushedResponses = [];
@@ -65,8 +65,17 @@ public function __construct(int $maxHostConnections, int $maxPendingPushes)
             return;
         }
 
-        curl_multi_setopt($this->handle, \CURLMOPT_PUSHFUNCTION, function ($parent, $pushed, array $requestHeaders) use ($maxPendingPushes) {
-            return $this->handlePush($parent, $pushed, $requestHeaders, $maxPendingPushes);
+        // Clone to prevent a circular reference
+        $multi = clone $this;
+        $multi->handle = null;
+        $multi->share = null;
+        $multi->pushedResponses = &$this->pushedResponses;
+        $multi->logger = &$this->logger;
+        $multi->handlesActivity = &$this->handlesActivity;
+        $multi->openHandles = &$this->openHandles;
+
+        curl_multi_setopt($this->handle, \CURLMOPT_PUSHFUNCTION, static function ($parent, $pushed, array $requestHeaders) use ($multi, $maxPendingPushes) {
+            return $multi->handlePush($parent, $pushed, $requestHeaders, $maxPendingPushes);
         });
     }