snapshot of https://github.com/grpc/grpc-go.git (master, 2026-09-15; blobs > 131072B omitted)

internal/transport/controlbuf_test.go

@@ -0,0 +1,85 @@
+/*
+ *
+ * Copyright 2026 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package transport
+
+import (
+	"testing"
+	"time"
+)
+
+func (s) TestControlBuffer_Throttle(t *testing.T) {
+	done := make(chan struct{})
+	defer close(done)
+	cb := newControlBuffer(done)
+
+	// Fill the control buffer up to the limit with throttled items.
+	for i := 0; i < maxQueuedControlBufferItems; i++ {
+		cb.put(&ping{})
+	}
+
+	// The next call to throttle should block.
+	throttleDone := make(chan struct{})
+	go func() {
+		cb.throttle()
+		close(throttleDone)
+	}()
+
+	select {
+	case <-throttleDone:
+		t.Fatal("throttle() did not block when the buffer was full")
+	case <-time.After(defaultTestShortTimeout):
+	}
+
+	// Consume one item from the control buffer.
+	if _, err := cb.get(true); err != nil {
+		t.Fatalf("cb.get(true) failed: %v", err)
+	}
+
+	// Now throttle() should unblock.
+	select {
+	case <-throttleDone:
+	case <-time.After(time.Second):
+		t.Fatal("throttle() did not unblock after an item was consumed")
+	}
+}
+
+func (s) TestControlBuffer_NoThrottleForNonThrottledItems(t *testing.T) {
+	done := make(chan struct{})
+	defer close(done)
+	cb := newControlBuffer(done)
+
+	// Fill the control buffer with many more than limit number of non-throttled
+	// items.
+	for i := 0; i < maxQueuedControlBufferItems+10; i++ {
+		cb.put(&dataFrame{})
+	}
+
+	// throttle() should not block.
+	throttled := make(chan struct{})
+	go func() {
+		cb.throttle()
+		close(throttled)
+	}()
+
+	select {
+	case <-throttled:
+	case <-time.After(defaultTestShortTimeout):
+		t.Fatal("throttle() blocked for non-throttled items")
+	}
+}