From 1cd41cc1596f2bb0d399a0c52ff92e8c3c5f4cca Mon Sep 17 00:00:00 2001
From: Daniil Gentili <daniil@daniil.it>
Date: Sun, 27 Sep 2020 21:51:55 +0200
Subject: [PATCH] Dark magic to allow serializing session to database on
 shutdown

---
 src/danog/MadelineProto/API.php               |  2 +-
 src/danog/MadelineProto/MTProto.php           | 37 ++++++++++++++++++-
 src/danog/MadelineProto/Magic.php             |  5 ++-
 .../MadelineProto/Settings/Connection.php     | 12 ++++++
 src/danog/MadelineProto/SettingsAbstract.php  |  2 +-
 src/danog/MadelineProto/Shutdown.php          |  1 +
 6 files changed, 53 insertions(+), 6 deletions(-)

diff --git a/src/danog/MadelineProto/API.php b/src/danog/MadelineProto/API.php
index 43dbd8b70..6503d4b00 100644
--- a/src/danog/MadelineProto/API.php
+++ b/src/danog/MadelineProto/API.php
@@ -255,7 +255,7 @@ class API extends InternalDoc
                 $this->API->destructing = true;
                 $this->API->unreference();
             }
-            if (isset($this->wrapper)) {
+            if (isset($this->wrapper) && !Magic::$signaled) {
                 $this->logger->logger('Prompting final serialization...');
                 Tools::wait($this->wrapper->serialize());
                 $this->logger->logger('Done final serialization!');
diff --git a/src/danog/MadelineProto/MTProto.php b/src/danog/MadelineProto/MTProto.php
index a12509ca1..8b7f7dd38 100644
--- a/src/danog/MadelineProto/MTProto.php
+++ b/src/danog/MadelineProto/MTProto.php
@@ -204,6 +204,20 @@ class MTProto extends AsyncConstruct implements TLCallback
         'msg_resend_ans_req',
     ];
     const DEFAULT_GETUPDATES_PARAMS = ['offset' => 0, 'limit' => null, 'timeout' => 100];
+    /**
+     * Array of references to all instances of MTProto.
+     *
+     * This seems like a recipe for memory leaks, but this is actually required to allow saving the session on shutdown.
+     * When using a network I/O-based database+the EvDriver of AMPHP, calling die(); causes premature garbage collection of the event loop.
+     * This garbage collection happens always, even if a reference to the event handler is already present elsewhere (probably ev dark magic).
+     *
+     * Finally, this causes the process to hang on shutdown, since the database driver cannot receive a reply from the server, because the event loop is down.
+     *
+     * To avoid this, we store each MTProto instance in here (unreferencing on shutdown in unreference()), and call serialize() on all instances before calling die; in Magic.
+     *
+     * @var self[]
+     */
+    public static array $references = [];
     /**
      * Instance of wrapper API.
      *
@@ -505,9 +519,23 @@ class MTProto extends AsyncConstruct implements TLCallback
             return $data;
         }
         yield $this->session->offsetSet('data', $data);
-        var_dump("Saved!");
         return $this->session;
     }
+    /**
+     * Serialize all instances.
+     *
+     * CALLED ONLY ON SHUTDOWN.
+     *
+     * @return void
+     */
+    public static function serializeAll(): void
+    {
+        Logger::log('Prompting final serialization (SHUTDOWN)...');
+        foreach (self::$references as $instance) {
+            Tools::wait($instance->wrapper->serialize());
+        }
+        Logger::log('Done final serialization (SHUTDOWN)!');
+    }
 
     /**
      * Constructor function.
@@ -519,6 +547,7 @@ class MTProto extends AsyncConstruct implements TLCallback
      */
     public function __magic_construct(SettingsAbstract $settings, APIWrapper $wrapper)
     {
+        self::$references[\spl_object_hash($this)] = $this;
         $this->wrapper = $wrapper;
         $this->setInitPromise($this->__construct_async($settings));
     }
@@ -1023,6 +1052,8 @@ class MTProto extends AsyncConstruct implements TLCallback
      */
     public function wakeup(SettingsAbstract $settings, APIWrapper $wrapper): \Generator
     {
+        // Set reference to itself
+        self::$references[\spl_object_hash($this)] = $this;
         // Set API wrapper
         $this->wrapper = $wrapper;
         // BC stuff
@@ -1132,6 +1163,9 @@ class MTProto extends AsyncConstruct implements TLCallback
     public function unreference(): void
     {
         $this->logger->logger("Will unreference instance");
+        if (isset(self::$references[\spl_object_hash($this)])) {
+            unset(self::$references[\spl_object_hash($this)]);
+        }
         $this->stopLoops();
         if (isset($this->seqUpdater)) {
             $this->seqUpdater->signal(true);
@@ -1153,7 +1187,6 @@ class MTProto extends AsyncConstruct implements TLCallback
             $datacenter->disconnect();
         }
         $this->logger->logger("Unreferenced instance");
-
     }
     /**
      * Destructor.
diff --git a/src/danog/MadelineProto/Magic.php b/src/danog/MadelineProto/Magic.php
index 051a6a58f..f28940f4c 100644
--- a/src/danog/MadelineProto/Magic.php
+++ b/src/danog/MadelineProto/Magic.php
@@ -59,7 +59,7 @@ class Magic
      */
     public static $isFork = false;
     /**
-     * Whether this is an IPC worker
+     * Whether this is an IPC worker.
      */
     public static bool $isIpcWorker = false;
     /**
@@ -234,7 +234,7 @@ class Magic
             // Setup error reporting
             \set_error_handler(['\\danog\\MadelineProto\\Exception', 'ExceptionErrorHandler']);
             \set_exception_handler(['\\danog\\MadelineProto\\Exception', 'ExceptionHandler']);
-            self::$isIpcWorker = defined(\MADELINE_WORKER_TYPE::class) ? \MADELINE_WORKER_TYPE === 'madeline-ipc' : false;
+            self::$isIpcWorker = \defined(\MADELINE_WORKER_TYPE::class) ? \MADELINE_WORKER_TYPE === 'madeline-ipc' : false;
             if (PHP_SAPI !== 'cli' && PHP_SAPI !== 'phpdbg') {
                 try {
                     \error_reporting(E_ALL);
@@ -412,6 +412,7 @@ class Magic
                 $driver->unreference($key);
             }
         }
+        MTProto::serializeAll();
         Loop::stop();
         die($code);
     }
diff --git a/src/danog/MadelineProto/Settings/Connection.php b/src/danog/MadelineProto/Settings/Connection.php
index 545131f41..5fa87b986 100644
--- a/src/danog/MadelineProto/Settings/Connection.php
+++ b/src/danog/MadelineProto/Settings/Connection.php
@@ -425,6 +425,18 @@ class Connection extends SettingsAbstract
         return $this;
     }
 
+    /**
+     * Set proxies.
+     *
+     * @param array $proxies Proxies
+     *
+     * @return self
+     */
+    public function setProxy(array $proxies): self
+    {
+        $this->proxy = $proxies;
+        return $this;
+    }
     /**
      * Clear proxies.
      *
diff --git a/src/danog/MadelineProto/SettingsAbstract.php b/src/danog/MadelineProto/SettingsAbstract.php
index 27c472db5..e01305841 100644
--- a/src/danog/MadelineProto/SettingsAbstract.php
+++ b/src/danog/MadelineProto/SettingsAbstract.php
@@ -46,7 +46,7 @@ abstract class SettingsAbstract
                     !isset($defaults[$name])
                     || $other->{$name} !== $defaults[$name] // Isn't equal to the default value
                 )
-                && $other->{$name} !== $this->{"get$uc"}
+                && $other->{$name} !== $this->{$name}
             ) {
                 $this->{"set$uc"}($other->{$name});
                 $this->changed = true;
diff --git a/src/danog/MadelineProto/Shutdown.php b/src/danog/MadelineProto/Shutdown.php
index 16923aebb..ab5b56e0d 100644
--- a/src/danog/MadelineProto/Shutdown.php
+++ b/src/danog/MadelineProto/Shutdown.php
@@ -52,6 +52,7 @@ class Shutdown
         foreach (self::$callbacks as $callback) {
             $callback();
         }
+        Magic::shutdown(0);
     }
     /**
      * Add a callback for script shutdown.