fix: log worker failures (#1437)

* Small fixes on error.

* Adds comments.

---------

Co-authored-by: Alliballibaba <alliballibaba@gmail.com>

Author: AlliBalliBaba

frankenphp.go

@@ -405,6 +405,7 @@ func go_ub_write(threadIndex C.uintptr_t, cBuf *C.char, length C.int) (C.size_t,
 	}
 
 	if fc.responseWriter == nil {
+		// probably starting a worker script, log the output
 		fc.logger.Info(writer.(*bytes.Buffer).String())
 	}
 
@@ -466,10 +467,15 @@ func addHeader(fc *frankenPHPContext, cString *C.char, length C.int) {
 func go_write_headers(threadIndex C.uintptr_t, status C.int, headers *C.zend_llist) C.bool {
 	fc := phpThreads[threadIndex].getRequestContext()
 
-	if fc.isDone || fc.responseWriter == nil {
+	if fc.isDone {
 		return C.bool(false)
 	}
 
+	if fc.responseWriter == nil {
+		// probably starting a worker script, pretend we wrote headers so PHP still calls ub_write
+		return C.bool(true)
+	}
+
 	current := headers.head
 	for current != nil {
 		h := (*C.sapi_header_struct)(unsafe.Pointer(&(current.data)))

threadworker.go

@@ -112,7 +112,7 @@ func tearDownWorkerScript(handler *workerThread, exitStatus int) {
 	}
 
 	// on exit status 0 we just run the worker script again
-	if exitStatus == 0 {
+	if exitStatus == 0 && !handler.isBootingScript {
 		// TODO: make the max restart configurable
 		metrics.StopWorker(worker.fileName, StopReasonRestart)
 		handler.backoff.recordSuccess()
@@ -122,10 +122,19 @@ func tearDownWorkerScript(handler *workerThread, exitStatus int) {
 		return
 	}
 
-	// on exit status 1 we apply an exponential backoff when restarting
+	// worker has thrown a fatal error or has not reached frankenphp_handle_request
 	metrics.StopWorker(worker.fileName, StopReasonCrash)
-	if handler.isBootingScript && handler.backoff.recordFailure() {
-		if !watcherIsEnabled {
+
+	if !handler.isBootingScript {
+		// fatal error (could be due to timeouts, etc.)
+		return
+	}
+
+	logger.Error("worker script has not reached frankenphp_handle_request", zap.String("worker", worker.fileName))
+
+	// panic after exponential backoff if the worker has never reached frankenphp_handle_request
+	if handler.backoff.recordFailure() {
+		if !watcherIsEnabled && !handler.state.is(stateReady) {
 			logger.Panic("too many consecutive worker failures", zap.String("worker", worker.fileName), zap.Int("failures", handler.backoff.failureCount))
 		}
 		logger.Warn("many consecutive worker failures", zap.String("worker", worker.fileName), zap.Int("failures", handler.backoff.failureCount))