Use tracing JIT to prevent performance test crashes

.github/workflows/performance-tests.yml

@@ -9,8 +9,10 @@ permissions:
 jobs:
   run:
     runs-on: ${{ matrix.operating-system }}
+    timeout-minutes: 15
 
     strategy:
+      fail-fast: false
       matrix:
         operating-system: [ ubuntu-latest ]
         php-version: [ '8.1', '8.2', '8.3', '8.4', '8.5' ]
@@ -27,11 +29,24 @@ jobs:
         with:
           php-version: ${{ matrix.php-version }}
           coverage: none
-          ini-values: opcache.enable_cli=1
+          # Keep JIT enabled while avoiding the function-JIT crash in PHPUnit's exporter (#92).
+          ini-values: opcache.enable_cli=1, opcache.jit=tracing, opcache.jit_buffer_size=256M
 
       - name: Check PHP version
         run: php -v
 
+      - name: Verify OPcache and tracing JIT
+        run: |
+          php -r '
+            $status = opcache_get_status(false);
+            $jit = $status["jit"] ?? [];
+            echo json_encode(["opcache_enabled" => $status["opcache_enabled"] ?? false, "jit" => $jit], JSON_PRETTY_PRINT), PHP_EOL;
+            if (!($status["opcache_enabled"] ?? false) || !($jit["enabled"] ?? false) || !($jit["on"] ?? false) || ($jit["kind"] ?? null) !== 5) {
+                fwrite(STDERR, "Expected OPcache and tracing JIT to be enabled.\n");
+                exit(1);
+            }
+          '
+
       - name: Cache Composer packages
         id: composer-cache
         uses: actions/cache@v3

PERFORMANCE.md

@@ -0,0 +1,55 @@
+# Performance testing
+
+Run the benchmark suite with:
+
+```sh
+composer run-script test-performance
+```
+
+The manually dispatched **PHP Performance Tests** workflow tests PHP 8.1–8.5
+on Ubuntu. It enables OPcache and tracing JIT explicitly:
+
+```ini
+opcache.enable_cli=1
+opcache.jit=tracing
+opcache.jit_buffer_size=256M
+```
+
+For local benchmarks, put these settings in the CLI `php.ini` used by both
+PHPUnit and its child PHP processes. Disable Xdebug and other coverage drivers
+when benchmarking. The workflow uses `coverage: none` and verifies that OPcache
+and tracing JIT are active before running tests.
+
+Record the PHP version, operating system, JIT mode, and coverage configuration
+when comparing timings. Results using tracing JIT should not be treated as
+directly comparable to results collected with a different JIT mode.
+
+## Why tracing JIT is explicit
+
+[Issue #92](https://github.com/okapi-web/php-aop/issues/92) tracks a PHP JIT
+compiler crash encountered during PHPUnit test discovery. `setup-php` supplies
+`opcache.jit=1235` by default; enabling CLI OPcache with coverage disabled
+activates that mode, which compiles hot functions. Tracing JIT (`1254`) uses
+a different compilation mode.
+
+The crash was reproduced with PHP 8.5.10 on Linux and Windows. In a PHP 8.5.10
+debug build under WSL, the debugger identified
+`SebastianBergmann\Exporter\Exporter::recursiveExport()` as the function being
+compiled. The engine failed the `count == 1` assertion in `ir_fix_bb_order()`
+at `ext/opcache/jit/ir/ir_gcm.c:944`. PHPUnit calls this exporter while formatting
+data-provider arguments, before executing the benchmarks.
+
+An exporter-only reproduction also fails without loading PHPUnit or AOP.
+`sebastian/exporter` is a development dependency here, not a runtime dependency
+of the library. This identifies the observed crash; it does not establish that
+all application code is unaffected by the underlying PHP engine bug.
+
+Tracing JIT avoids the observed crash while retaining JIT and OPcache for the
+library and benchmarks. This is a test-workflow workaround, not a PHP engine
+fix or a requirement for consumers to disable JIT. No application configuration
+is changed by the library.
+
+References:
+
+- [PHP JIT configuration](https://www.php.net/manual/en/opcache.configuration.php#ini.opcache.jit)
+- [setup-php JIT defaults](https://github.com/shivammathur/setup-php#jit-configuration)

README.md

@@ -760,6 +760,9 @@ $firstLog = $logs[0];
   or
 - Run `composer run-script test-coverage`
 
+For performance tests and the JIT configuration used by CI, see
+[Performance testing](PERFORMANCE.md).
+
 
 ## Contributing