diff --git a/.github/jit_check.php b/.github/jit_check.php
new file mode 100644
index 000000000000..50f3ac9ec383
--- /dev/null
+++ b/.github/jit_check.php
@@ -0,0 +1,30 @@
+<?php
+
+register_shutdown_function(function () {
+    $status = opcache_get_status(false);
+    var_dump($status);
+
+    if ($status["memory_usage"]["free_memory"] < 10*1024*1024) {
+        fwrite(STDERR, "Not enough free opcache memory!".PHP_EOL);
+    }
+    if ($status["interned_strings_usage"]["free_memory"] < 1*1024*1024) {
+        fwrite(STDERR, "Not enough free interned strings memory!".PHP_EOL);
+    }
+    if ($status["jit"]["buffer_free"] < 10*1024*1024) {
+        fwrite(STDERR, "Not enough free JIT memory!".PHP_EOL);
+    }
+    if (!$status["jit"]["on"]) {
+        fwrite(STDERR, "JIT is not enabled!".PHP_EOL);
+    }
+
+    unset($status);
+    while (gc_collect_cycles());
+});
+
+$argc--;
+array_shift($argv);
+
+$_SERVER['argc']--;
+array_shift($_SERVER['argv']);
+
+require $argv[0];
diff --git a/.github/nightly.php b/.github/nightly.php
new file mode 100644
index 000000000000..d289c9c5e6d4
--- /dev/null
+++ b/.github/nightly.php
@@ -0,0 +1,297 @@
+<?php
+
+putenv("ASAN_OPTIONS=exitcode=139");
+putenv("SYMFONY_DEPRECATIONS_HELPER=max[total]=999");
+putenv("PHPSECLIB_ALLOW_JIT=1");
+
+function printMutex(string $result): void {
+    flock(STDOUT, LOCK_EX);
+    fwrite(STDOUT, $result.PHP_EOL);
+    flock(STDOUT, LOCK_UN);
+}
+
+function e(string $cmd, string $extra = ''): string {
+    exec("bash -c ".escapeshellarg("$cmd 2>&1"), $result, $code);
+    $result = implode("\n", $result);
+    if ($code) {
+        printMutex("An error occurred while executing $cmd (status $code, extra info $extra): $result");
+        die(1);
+    }
+    return $result;
+}
+
+$parallel = (int) ($argv[1] ?? 0);
+$parallel = $parallel ?: ((int)`nproc`);
+$parallel = $parallel ?: 8;
+
+$repos = [];
+
+$repos["psalm"] = [
+    "https://github.com/vimeo/psalm",
+    "master",
+    null,
+    function (): iterable {
+        $it = new RecursiveDirectoryIterator("tests");
+        /** @var SplFileInfo $file */
+        foreach(new RecursiveIteratorIterator($it) as $file) {
+            if ($file->getExtension() == 'php' && ctype_upper($file->getBasename()[0])) {
+                yield [
+                    getcwd()."/vendor/bin/phpunit",
+                    $file->getRealPath(),
+                ];
+            }
+        }
+    },
+    2
+];
+
+$repos["phpseclib"] = [
+    "https://github.com/phpseclib/phpseclib",
+    "master",
+    null,
+    function (): iterable {
+        $it = new RecursiveDirectoryIterator("tests");
+        /** @var SplFileInfo $file */
+        foreach(new RecursiveIteratorIterator($it) as $file) {
+            if ($file->getExtension() == 'php' && ctype_upper($file->getBasename()[0])) {
+                yield [
+                    getcwd()."/vendor/bin/phpunit",
+                    '-c',
+                    getcwd()."/tests/phpunit.xml",
+                    $file->getRealPath(),
+                ];
+            }
+        }
+    },
+    2
+];
+
+$repos["phpunit"] = [
+    "https://github.com/sebastianbergmann/phpunit.git",
+    "main",
+    null,
+    ["./phpunit"],
+    2
+];
+
+$repos["infection"] = [
+    "https://github.com/infection/infection",
+    "master",
+    null,
+    ["vendor/bin/phpunit"],
+    2
+];
+
+$repos["wordpress"] = [
+    "https://github.com/WordPress/wordpress-develop.git",
+    "",
+    function (): void {
+        $f = file_get_contents('wp-tests-config-sample.php');
+        $f = str_replace('youremptytestdbnamehere', 'test', $f);
+        $f = str_replace('yourusernamehere', 'root', $f);
+        $f = str_replace('yourpasswordhere', 'root', $f);
+        file_put_contents('wp-tests-config.php', $f);
+    },
+    ["vendor/bin/phpunit"],
+    2
+];
+
+foreach (['amp', 'cache', 'dns', 'file', 'http', 'parallel', 'parser', 'pipeline', 'process', 'serialization', 'socket', 'sync', 'websocket-client', 'websocket-server'] as $repo) {
+    $repos["amphp-$repo"] = ["https://github.com/amphp/$repo.git", "", null, ["vendor/bin/phpunit"], 2];
+}
+
+$repos["laravel"] = [
+    "https://github.com/laravel/framework.git",
+    "master",
+    function (): void {
+        $c = file_get_contents("tests/Filesystem/FilesystemTest.php"); 
+        $c = str_replace("public function testSharedGet()", "#[\\PHPUnit\\Framework\\Attributes\\Group('skip')]\n    public function testSharedGet()", $c);
+        file_put_contents("tests/Filesystem/FilesystemTest.php", $c);
+    },
+    ["vendor/bin/phpunit", "--exclude-group", "skip"],
+    2
+];
+
+foreach (['async', 'cache', 'child-process', 'datagram', 'dns', 'event-loop', 'promise', 'promise-stream', 'promise-timer', 'stream'] as $repo) {
+    $repos["reactphp-$repo"] = ["https://github.com/reactphp/$repo.git", "", null, ["vendor/bin/phpunit"], 2];
+}
+
+$repos["revolt"] = ["https://github.com/revoltphp/event-loop.git", "", null, ["vendor/bin/phpunit"], 2];
+
+$repos["symfony"] = [
+    "https://github.com/symfony/symfony.git",
+    "",
+    function (): void {
+        e("php ./phpunit install");
+    },
+    function (): iterable {
+        $it = new RecursiveDirectoryIterator("src/Symfony");
+        /** @var SplFileInfo $file */
+        foreach(new RecursiveIteratorIterator($it) as $file) {
+            if ($file->getBasename() == 'phpunit.xml.dist') {
+                yield [
+                    getcwd()."/phpunit",
+                    dirname($file->getRealPath()), 
+                    "--exclude-group",
+                    "tty,benchmark,intl-data,transient",
+                    "--exclude-group",
+                    "skip"
+                ];
+            }
+        }
+    },
+    2
+];
+
+$finalStatus = 0;
+$parentPids = [];
+
+$waitOne = function () use (&$finalStatus, &$parentPids): void {
+    $res = pcntl_wait($status);
+    if ($res === -1) {
+        printMutex("An error occurred while waiting with waitpid!");
+        $finalStatus = $finalStatus ?: 1;
+        return;
+    }
+    if (!isset($parentPids[$res])) {
+        printMutex("Unknown PID $res returned!");
+        $finalStatus = $finalStatus ?: 1;
+        return;
+    }
+    $desc = $parentPids[$res];
+    unset($parentPids[$res]);
+    if (pcntl_wifexited($status)) {
+        $status = pcntl_wexitstatus($status);
+        printMutex("Child task $desc exited with status $status");
+        if ($status !== 0) {
+            $finalStatus = $status;
+        }
+    } elseif (pcntl_wifstopped($status)) {
+        $status = pcntl_wstopsig($status);
+        printMutex("Child task $desc stopped by signal $status");
+        $finalStatus = 1;
+    } elseif (pcntl_wifsignaled($status)) {
+        $status = pcntl_wtermsig($status);
+        printMutex("Child task $desc terminated by signal $status");
+        $finalStatus = 1;
+    }
+};
+
+$waitAll = function () use ($waitOne, &$parentPids): void {
+    while ($parentPids) {
+        $waitOne();
+    }
+};
+
+printMutex("Cloning repos...");
+
+foreach ($repos as $dir => [$repo, $branch, $prepare, $command, $repeat]) {
+    $pid = pcntl_fork();
+    if ($pid) {
+        $parentPids[$pid] = "clone $dir";
+        continue;
+    }
+
+    chdir(sys_get_temp_dir());
+    if ($branch) {
+        $branch = "--branch $branch";
+    }
+    e("git clone $repo $branch --depth 1 $dir");
+    
+    exit(0);
+}
+
+$waitAll();
+
+printMutex("Done cloning repos!");
+
+printMutex("Preparing repos (max $parallel processes)...");
+foreach ($repos as $dir => [$repo, $branch, $prepare, $command, $repeat]) {
+    chdir(sys_get_temp_dir()."/$dir");
+    $rev = e("git rev-parse HEAD", $dir);
+
+    $pid = pcntl_fork();
+    if ($pid) {
+        $parentPids[$pid] = "prepare $dir ($rev)";
+        if (count($parentPids) >= $parallel) {
+            $waitOne();
+        }
+        continue;
+    }
+
+    e("composer i --ignore-platform-reqs", $dir);
+    if ($prepare) {
+        $prepare();
+    }
+
+    exit(0);
+}
+$waitAll();
+
+printMutex("Done preparing repos!");
+
+printMutex("Running tests (max $parallel processes)...");
+foreach ($repos as $dir => [$repo, $branch, $prepare, $command, $repeat]) {
+    chdir(sys_get_temp_dir()."/$dir");
+    $rev = e("git rev-parse HEAD", $dir);
+
+    if ($command instanceof Closure) {
+        $commands = iterator_to_array($command());
+    } else {
+        $commands = [$command];
+    }
+
+    foreach ($commands as $idx => $cmd) {
+        $cmd = array_merge([
+            PHP_BINARY,
+            '--repeat',
+            $repeat,
+            '-f',
+            __DIR__.'/jit_check.php',
+        ], $cmd);
+
+        $cmdStr = implode(" ", $cmd);
+
+        $pid = pcntl_fork();
+        if ($pid) {
+            $parentPids[$pid] = "test $dir ($rev): $cmdStr";
+            if (count($parentPids) >= $parallel) {
+                $waitOne();
+            }
+            continue;
+        }
+
+        $output = sys_get_temp_dir()."/out_{$dir}_$idx.txt";
+        
+        $p = proc_open($cmd, [
+            ["pipe", "r"], 
+            ["file", $output, "a"],
+            ["file", $output, "a"]
+        ], $pipes, sys_get_temp_dir()."/$dir");
+
+        if ($p === false) {
+            printMutex("Failure starting $cmdStr");
+            exit(1);
+        }
+        
+        $final = 0;
+        $status = proc_close($p);
+        if ($status !== 0) {
+            if ($status > 128) {
+                $final = $status;
+            }
+            printMutex(
+                "$dir ($rev): $cmdStr terminated with status $status:".PHP_EOL
+                .file_get_contents($output).PHP_EOL
+            );
+        }
+
+        exit($final);
+    }
+}
+
+$waitAll();
+
+printMutex("All done!");
+
+die($finalStatus);
diff --git a/.github/workflows/nightly.yml b/.github/workflows/nightly.yml
index 1b1532af7f79..58e48ff19136 100644
--- a/.github/workflows/nightly.yml
+++ b/.github/workflows/nightly.yml
@@ -174,8 +174,8 @@ jobs:
             configuration_parameters: >-
               CFLAGS="-fsanitize=undefined,address -DZEND_TRACK_ARENA_ALLOC"
               LDFLAGS="-fsanitize=undefined,address"
-            run_tests_parameters: '--asan'
-            test_function_jit: false
+            run_tests_parameters: '--asan --repeat 2'
+            test_function_jit: true
             asan: true
           - name: _REPEAT
             debug: true
@@ -535,106 +535,34 @@ jobs:
         run: |
           echo opcache.jit=tracing >> /etc/php.d/opcache.ini
           echo opcache.jit_buffer_size=1G >> /etc/php.d/opcache.ini
+          echo opcache.jit_prof_threshold=0.000000001 >> /etc/php.d/opcache.ini
           echo opcache.jit_max_root_traces=100000 >> /etc/php.d/opcache.ini
           echo opcache.jit_max_side_traces=100000 >> /etc/php.d/opcache.ini
           echo opcache.jit_max_exit_counters=100000 >> /etc/php.d/opcache.ini
+          echo opcache.jit_blacklist_root_trace=255 >> /etc/php.d/opcache.ini
+          echo opcache.jit_blacklist_side_trace=255 >> /etc/php.d/opcache.ini
           echo opcache.jit_hot_loop=1 >> /etc/php.d/opcache.ini
           echo opcache.jit_hot_func=1 >> /etc/php.d/opcache.ini
           echo opcache.jit_hot_return=1 >> /etc/php.d/opcache.ini
           echo opcache.jit_hot_side_exit=1 >> /etc/php.d/opcache.ini
           php -v
-      - name: Test AMPHP
-        if: ${{ !cancelled() }}
-        run: |
-          repositories="amp cache dns file http parallel parser pipeline process serialization socket sync websocket-client websocket-server"
-          X=0
-          for repository in $repositories; do
-            printf "Testing amp/%s\n" "$repository"
-            git clone "https://github.com/amphp/$repository.git" "amphp-$repository" --depth 1
-            cd "amphp-$repository"
-            git rev-parse HEAD
-            php /usr/bin/composer install --no-progress --ignore-platform-req=php+
-            vendor/bin/phpunit || EXIT_CODE=$?
-            if [ ${EXIT_CODE:-0} -gt 128 ]; then
-              X=1;
-            fi
-            cd ..
-          done
-          exit $X
-      - name: Test Laravel
-        if: ${{ !cancelled() && !inputs.skip_laravel }}
-        run: |
-          git clone https://github.com/laravel/framework.git --depth=1
-          cd framework
-          git rev-parse HEAD
-          php /usr/bin/composer install --no-progress --ignore-platform-req=php+
-          # Hack to disable a test that hangs
-          php -r '$c = file_get_contents("tests/Filesystem/FilesystemTest.php"); $c = str_replace("public function testSharedGet()", "#[\\PHPUnit\\Framework\\Attributes\\Group('"'"'skip'"'"')]\n    public function testSharedGet()", $c); file_put_contents("tests/Filesystem/FilesystemTest.php", $c);'
-          php vendor/bin/phpunit --exclude-group skip || EXIT_CODE=$?
-          if [ ${EXIT_CODE:-0} -gt 128 ]; then
-            exit 1
-          fi
-      - name: Test ReactPHP
-        if: ${{ !cancelled() }}
-        run: |
-          repositories="async cache child-process datagram dns event-loop promise promise-stream promise-timer stream"
-          X=0
-          for repository in $repositories; do
-            printf "Testing reactphp/%s\n" "$repository"
-            git clone "https://github.com/reactphp/$repository.git" "reactphp-$repository" --depth 1
-            cd "reactphp-$repository"
-            git rev-parse HEAD
-            php /usr/bin/composer install --no-progress --ignore-platform-req=php+
-            vendor/bin/phpunit || EXIT_CODE=$?
-            if [ $[EXIT_CODE:-0} -gt 128 ]; then
-              X=1;
-            fi
-            cd ..
-          done
-          exit $X
-      - name: Test Revolt PHP
-        if: ${{ !cancelled() }}
-        run: |
-          git clone https://github.com/revoltphp/event-loop.git --depth=1
-          cd event-loop
-          git rev-parse HEAD
-          php /usr/bin/composer install --no-progress --ignore-platform-req=php+
-          vendor/bin/phpunit || EXIT_CODE=$?
-          if [ ${EXIT_CODE:-0} -gt 128 ]; then
-            exit 1
-          fi
-      - name: Test Symfony
-        if: ${{ !cancelled() && !inputs.skip_symfony }}
+
+      - name: Test multiple libraries and frameworks in parallel
         run: |
-          git clone https://github.com/symfony/symfony.git --depth=1
-          cd symfony
-          git rev-parse HEAD
-          php /usr/bin/composer install --no-progress --ignore-platform-req=php+
-          php ./phpunit install
-          # Test causes a heap-buffer-overflow but I cannot reproduce it locally...
-          php -r '$c = file_get_contents("src/Symfony/Component/HtmlSanitizer/Tests/HtmlSanitizerCustomTest.php"); $c = str_replace("public function testSanitizeDeepNestedString()", "/** @group skip */\n    public function testSanitizeDeepNestedString()", $c); file_put_contents("src/Symfony/Component/HtmlSanitizer/Tests/HtmlSanitizerCustomTest.php", $c);'
-          # Buggy FFI test in Symfony, see https://github.com/symfony/symfony/issues/47668
-          php -r '$c = file_get_contents("src/Symfony/Component/VarDumper/Tests/Caster/FFICasterTest.php"); $c = str_replace("public function testCastNonTrailingCharPointer()", "/** @group skip */\n    public function testCastNonTrailingCharPointer()", $c); file_put_contents("src/Symfony/Component/VarDumper/Tests/Caster/FFICasterTest.php", $c);'
-          export SYMFONY_DEPRECATIONS_HELPER=max[total]=999
-          X=0
-          for component in $(find src/Symfony -mindepth 2 -type f -name phpunit.xml.dist -printf '%h\n'); do
-            php ./phpunit $component --exclude-group tty,benchmark,intl-data,transient --exclude-group skip || EXIT_CODE=$?
-            if [ ${EXIT_CODE:-0} -gt 128 ]; then
-              X=1;
-            fi
-          done
-          exit $X
-      - name: Test PHPUnit
-        if: ${{ !cancelled() }}
+          sudo prlimit --pid $$ --nofile=1048576:1048576
+          
+          php $GITHUB_WORKSPACE/.github/nightly.php || exit $?
+
+      - name: Test PHPSeclib
+        if: always()
         run: |
-          git clone https://github.com/sebastianbergmann/phpunit.git --branch=main --depth=1
-          cd phpunit
-          git rev-parse HEAD
-          php /usr/bin/composer install --no-progress --ignore-platform-req=php+
-          php ./phpunit || EXIT_CODE=$?
-          if [ ${EXIT_CODE:-0} -gt 128 ]; then
-            exit 1
-          fi
+          git clone https://github.com/phpseclib/phpseclib --branch=master
+          cd phpseclib
+          export ASAN_OPTIONS=exitcode=139
+          export PHPSECLIB_ALLOW_JIT=1
+          php /usr/bin/composer install --no-progress --ignore-platform-reqs
+          php $GITHUB_WORKSPACE/.github/jit_check.php vendor/bin/paratest --verbose --configuration=tests/phpunit.xml --runner=WrapperRunner || exit $?
+
       - name: 'Symfony Preloading'
         if: ${{ !cancelled() && !inputs.skip_symfony }}
         run: |
@@ -643,21 +571,6 @@ jobs:
           git rev-parse HEAD
           sed -i 's/PHP_SAPI/"cli-server"/g' var/cache/dev/App_KernelDevDebugContainer.preload.php
           php -d opcache.preload=var/cache/dev/App_KernelDevDebugContainer.preload.php public/index.php
-      - name: Test Wordpress
-        if: ${{ !cancelled() && !inputs.skip_wordpress }}
-        run: |
-          git clone https://github.com/WordPress/wordpress-develop.git wordpress --depth=1
-          cd wordpress
-          git rev-parse HEAD
-          php /usr/bin/composer install --no-progress --ignore-platform-req=php+
-          cp wp-tests-config-sample.php wp-tests-config.php
-          sed -i 's/youremptytestdbnamehere/test/g' wp-tests-config.php
-          sed -i 's/yourusernamehere/root/g' wp-tests-config.php
-          sed -i 's/yourpasswordhere/root/g' wp-tests-config.php
-          php vendor/bin/phpunit || EXIT_CODE=$?
-          if [ $EXIT_CODE -gt 128 ]; then
-            exit 1
-          fi
       - name: Notify Slack
         if: failure()
         uses: ./.github/actions/notify-slack