1 files changed, 115 insertions, 0 deletions
diff --git a/ipc/ipdl/test/gtest/TestUrgency.cpp b/ipc/ipdl/test/gtest/TestUrgency.cpp
new file mode 100644
index 0000000000..a4f7d0ea3e
--- /dev/null
+++ b/ipc/ipdl/test/gtest/TestUrgency.cpp
@@ -0,0 +1,115 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 that sync messages preempt other messages in the expected way.
+ */
+
+#include "gtest/gtest.h"
+
+#include "mozilla/_ipdltest/IPDLUnitTest.h"
+#include "mozilla/_ipdltest/PTestUrgencyChild.h"
+#include "mozilla/_ipdltest/PTestUrgencyParent.h"
+
+using namespace mozilla::ipc;
+
+namespace mozilla::_ipdltest {
+
+enum {
+  kFirstTestBegin = 1,
+  kFirstTestGotReply,
+  kSecondTestBegin,
+  kSecondTestGotReply,
+};
+
+class TestUrgencyParent : public PTestUrgencyParent {
+  NS_INLINE_DECL_REFCOUNTING(TestUrgencyParent, override)
+ private:
+  IPCResult RecvTest1(uint32_t* value) final override {
+    EXPECT_TRUE(SendReply1(value));
+    EXPECT_EQ(*value, (uint32_t)99) << "unexpected value";
+    return IPC_OK();
+  }
+
+  IPCResult RecvTest2() final override {
+    uint32_t value;
+    inreply_ = true;
+    EXPECT_TRUE(SendReply2(&value));
+    inreply_ = false;
+    EXPECT_EQ(value, (uint32_t)500) << "unexpected value";
+    return IPC_OK();
+  }
+
+  IPCResult RecvTest3(uint32_t* value) final override {
+    EXPECT_FALSE(inreply_) << "nested non-urgent on top of urgent message";
+    *value = 1000;
+    return IPC_OK();
+  }
+
+  IPCResult RecvFinalTest_Begin() final override { return IPC_OK(); }
+
+  ~TestUrgencyParent() = default;
+
+  bool inreply_ = false;
+};
+
+class TestUrgencyChild : public PTestUrgencyChild {
+  NS_INLINE_DECL_REFCOUNTING(TestUrgencyChild, override)
+ private:
+  IPCResult RecvStart() final override {
+    uint32_t result;
+
+    // Send a synchronous message, expect to get an urgent message while
+    // blocked.
+    test_ = kFirstTestBegin;
+    EXPECT_TRUE(SendTest1(&result));
+    EXPECT_EQ(result, (uint32_t)99) << "wrong value from SendTest1";
+    EXPECT_EQ(test_, kFirstTestGotReply)
+        << "never received first urgent message";
+
+    // Initiate the next test by sending an asynchronous message, then becoming
+    // blocked. This tests that the urgent message is still delivered properly,
+    // and that the parent does not try to service the sync
+    test_ = kSecondTestBegin;
+    EXPECT_TRUE(SendTest2());
+    EXPECT_TRUE(SendTest3(&result));
+    EXPECT_EQ(test_, kSecondTestGotReply)
+        << "never received second urgent message";
+    EXPECT_EQ(result, (uint32_t)1000) << "wrong value from SendTest3";
+
+    EXPECT_TRUE(SendFinalTest_Begin());
+
+    Close();
+
+    return IPC_OK();
+  }
+
+  IPCResult RecvReply1(uint32_t* reply) final override {
+    EXPECT_EQ(test_, kFirstTestBegin) << "wrong test state in RecvReply1";
+
+    *reply = 99;
+    test_ = kFirstTestGotReply;
+    return IPC_OK();
+  }
+
+  IPCResult RecvReply2(uint32_t* reply) final override {
+    EXPECT_EQ(test_, kSecondTestBegin) << "wrong test state in RecvReply2";
+
+    *reply = 500;
+    test_ = kSecondTestGotReply;
+    return IPC_OK();
+  }
+
+  ~TestUrgencyChild() = default;
+
+  uint32_t test_ = 0;
+};
+
+// Only run cross-process because we need to send nested sync messages (this can
+// only be done from the main thread).
+IPDL_TEST_ON(CROSSPROCESS, TestUrgency) { EXPECT_TRUE(mActor->SendStart()); }
+
+}  // namespace mozilla::_ipdltest