fix: refuse to start on a ZTS build with Zend signals

frankenphp.go

@@ -46,6 +46,7 @@ var (
 	ErrInvalidRequest     = errors.New("not a FrankenPHP request")
 	ErrAlreadyStarted     = errors.New("FrankenPHP is already started")
 	ErrInvalidPHPVersion  = errors.New("FrankenPHP is only compatible with PHP 8.2+")
+	ErrZendSignals        = errors.New(`FrankenPHP is not compatible with Zend Signals, recompile PHP with the "--disable-zend-signals" configuration option`)
 	ErrMainThreadCreation = errors.New("error creating the main thread")
 	ErrScriptExecution    = errors.New("error during PHP script execution")
 	ErrNotRunning         = errors.New("server is not registered, you must first call frankenphp.Init() with the WithServer() option")
@@ -156,6 +157,21 @@ func Config() PHPConfig {
 	}
 }
 
+// checkPHPConfig rejects the PHP builds FrankenPHP cannot run on
+func checkPHPConfig(config PHPConfig) error {
+	if config.Version.MajorVersion < 8 || (config.Version.MajorVersion == 8 && config.Version.MinorVersion < 2) {
+		return ErrInvalidPHPVersion
+	}
+
+	// FrankenPHP never calls zend_signal_startup(), so in ZTS the ini entries
+	// of the signal globals overwrite the TSRM entry of each thread
+	if config.ZTS && config.ZendSignals {
+		return ErrZendSignals
+	}
+
+	return nil
+}
+
 func calculateMaxThreads(opt *opt) (numWorkers int, _ error) {
 	maxProcs := runtime.GOMAXPROCS(0) * 2
 	maxThreadsFromWorkers := 0
@@ -294,9 +310,10 @@ func Init(options ...Option) error {
 
 	config := Config()
 
-	if config.Version.MajorVersion < 8 || (config.Version.MajorVersion == 8 && config.Version.MinorVersion < 2) {
+	if err := checkPHPConfig(config); err != nil {
 		shutdown()
-		return ErrInvalidPHPVersion
+
+		return err
 	}
 
 	if config.ZTS {

phpconfig_test.go

@@ -0,0 +1,36 @@
+package frankenphp
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCheckPHPConfig(t *testing.T) {
+	supported := PHPConfig{Version: PHPVersion{MajorVersion: 8, MinorVersion: 2}, ZTS: true}
+
+	t.Run("a supported build is accepted", func(t *testing.T) {
+		require.NoError(t, checkPHPConfig(supported))
+	})
+
+	t.Run("PHP older than 8.2 is rejected", func(t *testing.T) {
+		old := supported
+		old.Version.MinorVersion = 1
+		assert.ErrorIs(t, checkPHPConfig(old), ErrInvalidPHPVersion)
+	})
+
+	t.Run("Zend signals are rejected in ZTS", func(t *testing.T) {
+		signals := supported
+		signals.ZendSignals = true
+		assert.ErrorIs(t, checkPHPConfig(signals), ErrZendSignals)
+	})
+
+	t.Run("Zend signals are allowed without ZTS", func(t *testing.T) {
+		// without ZTS the ini entries address the globals directly
+		signals := supported
+		signals.ZTS = false
+		signals.ZendSignals = true
+		require.NoError(t, checkPHPConfig(signals))
+	})
+}