1 files changed, 88 insertions, 0 deletions
diff --git a/ipc/ipdl/test/gtest/TestMostNested.cpp b/ipc/ipdl/test/gtest/TestMostNested.cpp
new file mode 100644
index 0000000000..d3fb3582c6
--- /dev/null
+++ b/ipc/ipdl/test/gtest/TestMostNested.cpp
@@ -0,0 +1,88 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: sw=2 ts=4 et :
+ */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * Test nested sync message priorities.
+ */
+
+#include "gtest/gtest.h"
+
+#include "mozilla/_ipdltest/IPDLUnitTest.h"
+#include "mozilla/_ipdltest/PTestMostNestedChild.h"
+#include "mozilla/_ipdltest/PTestMostNestedParent.h"
+
+#if defined(XP_UNIX)
+#  include <unistd.h>
+#else
+#  include <windows.h>
+#endif
+
+using namespace mozilla::ipc;
+
+namespace mozilla::_ipdltest {
+
+class TestMostNestedChild : public PTestMostNestedChild {
+  NS_INLINE_DECL_REFCOUNTING(TestMostNestedChild, override)
+ private:
+  IPCResult RecvStart() final override {
+    EXPECT_TRUE(SendMsg1());
+    EXPECT_TRUE(SendMsg2());
+
+    Close();
+    return IPC_OK();
+  }
+
+  IPCResult RecvStartInner() final override {
+    EXPECT_TRUE(SendMsg3());
+    EXPECT_TRUE(SendMsg4());
+
+    return IPC_OK();
+  }
+
+  ~TestMostNestedChild() = default;
+};
+
+class TestMostNestedParent : public PTestMostNestedParent {
+  NS_INLINE_DECL_REFCOUNTING(TestMostNestedParent, override)
+ private:
+  IPCResult RecvMsg1() final override {
+    EXPECT_EQ(msg_num, 0);
+    msg_num = 1;
+    return IPC_OK();
+  }
+
+  IPCResult RecvMsg2() final override {
+    EXPECT_EQ(msg_num, 1);
+    msg_num = 2;
+
+    EXPECT_TRUE(SendStartInner());
+
+    return IPC_OK();
+  }
+
+  IPCResult RecvMsg3() final override {
+    EXPECT_EQ(msg_num, 2);
+    msg_num = 3;
+    return IPC_OK();
+  }
+
+  IPCResult RecvMsg4() final override {
+    EXPECT_EQ(msg_num, 3);
+    msg_num = 4;
+    return IPC_OK();
+  }
+
+  ~TestMostNestedParent() = default;
+
+  int msg_num = 0;
+};
+
+// Can only run cross-process because nested sync messages have to come from the
+// main thread.
+IPDL_TEST_ON(CROSSPROCESS, TestMostNested) { EXPECT_TRUE(mActor->SendStart()); }
+
+}  // namespace mozilla::_ipdltest