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-rw-r--r--xpcom/tests/gtest/TestRWLock.cpp214
1 files changed, 214 insertions, 0 deletions
diff --git a/xpcom/tests/gtest/TestRWLock.cpp b/xpcom/tests/gtest/TestRWLock.cpp
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+++ b/xpcom/tests/gtest/TestRWLock.cpp
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+/* -*- 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/. */
+
+#include "nsThreadUtils.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/gtest/MozAssertions.h"
+#include "mozilla/RWLock.h"
+#include "mozilla/SyncRunnable.h"
+#include "nsIThread.h"
+#include "gtest/gtest.h"
+
+using mozilla::AutoReadLock;
+using mozilla::AutoTryReadLock;
+using mozilla::AutoTryWriteLock;
+using mozilla::AutoWriteLock;
+using mozilla::RWLock;
+
+static const size_t sNumThreads = 4;
+static const size_t sOuterIterations = 100;
+static const size_t sInnerIterations = 100;
+static const size_t sWriteLockIteration = 10;
+
+// Based on example code from _Programming with POSIX Threads_. Not an actual
+// test of correctness, but more of a "does this work at all" sort of test.
+
+class RWLockRunnable : public mozilla::Runnable {
+ public:
+ RWLockRunnable(RWLock* aRWLock, mozilla::Atomic<size_t>* aSharedData)
+ : mozilla::Runnable("RWLockRunnable"),
+ mRWLock(aRWLock),
+ mSharedData(aSharedData) {}
+
+ NS_DECL_NSIRUNNABLE
+
+ private:
+ ~RWLockRunnable() = default;
+
+ RWLock* mRWLock;
+ mozilla::Atomic<size_t>* mSharedData;
+};
+
+NS_IMETHODIMP
+RWLockRunnable::Run() {
+ for (size_t i = 0; i < sOuterIterations; ++i) {
+ if (i % sWriteLockIteration == 0) {
+ mozilla::AutoWriteLock lock(*mRWLock);
+
+ ++(*mSharedData);
+ } else {
+ mozilla::AutoReadLock lock(*mRWLock);
+
+ // Loop and try to force other threads to run, but check that our
+ // shared data isn't being modified by them.
+ size_t initialValue = *mSharedData;
+ for (size_t j = 0; j < sInnerIterations; ++j) {
+ EXPECT_EQ(initialValue, *mSharedData);
+
+ // This is a magic yield call.
+ PR_Sleep(PR_INTERVAL_NO_WAIT);
+ }
+ }
+ }
+
+ return NS_OK;
+}
+
+TEST(RWLock, SmokeTest)
+{
+ nsCOMPtr<nsIThread> threads[sNumThreads];
+ RWLock rwlock MOZ_UNANNOTATED("test lock");
+ mozilla::Atomic<size_t> data(0);
+
+ for (size_t i = 0; i < sNumThreads; ++i) {
+ nsCOMPtr<nsIRunnable> event = new RWLockRunnable(&rwlock, &data);
+ NS_NewNamedThread("RWLockTester", getter_AddRefs(threads[i]), event);
+ }
+
+ // Wait for all the threads to finish.
+ for (size_t i = 0; i < sNumThreads; ++i) {
+ nsresult rv = threads[i]->Shutdown();
+ EXPECT_NS_SUCCEEDED(rv);
+ }
+
+ EXPECT_EQ(data, (sOuterIterations / sWriteLockIteration) * sNumThreads);
+}
+
+template <typename Function>
+static std::invoke_result_t<Function> RunOnBackgroundThread(
+ Function&& aFunction) {
+ using Result = std::invoke_result_t<Function>;
+ nsCOMPtr<nsISerialEventTarget> thread;
+ MOZ_ALWAYS_SUCCEEDS(NS_CreateBackgroundTaskQueue(
+ "TestRWLock Background Thread", getter_AddRefs(thread)));
+ mozilla::Maybe<Result> tryResult;
+ RefPtr<nsIRunnable> runnable =
+ NS_NewRunnableFunction(__func__, [&] { tryResult.emplace(aFunction()); });
+ MOZ_ALWAYS_SUCCEEDS(
+ mozilla::SyncRunnable::DispatchToThread(thread.get(), runnable));
+ return *tryResult;
+}
+
+TEST(RWLock, AutoTryReadLock)
+{
+ RWLock l1 MOZ_UNANNOTATED("autotryreadlock");
+ {
+ AutoTryReadLock autol1(l1);
+
+ EXPECT_TRUE(autol1);
+
+ AutoTryReadLock autol2(l1);
+ EXPECT_TRUE(autol2);
+
+ EXPECT_TRUE(RunOnBackgroundThread([&] {
+ AutoTryReadLock lock(l1);
+ return !!lock;
+ }));
+
+ EXPECT_TRUE(autol1);
+ EXPECT_TRUE(autol2);
+
+ {
+ RWLock l2 MOZ_UNANNOTATED("autotryreadlock2");
+ AutoTryReadLock autol3(l2);
+
+ EXPECT_TRUE(autol3);
+ }
+
+ EXPECT_TRUE(autol1);
+ EXPECT_TRUE(autol2);
+ }
+
+ {
+ AutoWriteLock autol4(l1);
+ MOZ_ASSERT(l1.LockedForWritingByCurrentThread());
+
+ AutoTryReadLock autol5(l1);
+ EXPECT_FALSE(autol5);
+
+ EXPECT_FALSE(RunOnBackgroundThread([&] {
+ AutoTryReadLock lock(l1);
+ return !!lock;
+ }));
+ }
+
+ AutoTryReadLock autol6(l1);
+ EXPECT_TRUE(autol6);
+
+ EXPECT_TRUE(RunOnBackgroundThread([&] {
+ AutoTryReadLock lock(l1);
+ return !!lock;
+ }));
+}
+
+TEST(RWLock, AutoTryWriteLock)
+{
+ RWLock l1 MOZ_UNANNOTATED("autotrywritelock");
+ {
+ AutoTryWriteLock autol1(l1);
+
+ EXPECT_TRUE(autol1);
+
+ AutoTryReadLock autol2(l1);
+ EXPECT_FALSE(autol2);
+
+ EXPECT_FALSE(RunOnBackgroundThread([&] {
+ AutoTryWriteLock lock(l1);
+ return !!lock;
+ }));
+
+ EXPECT_TRUE(autol1);
+ EXPECT_FALSE(autol2);
+
+ {
+ RWLock l2 MOZ_UNANNOTATED("autotrywritelock2");
+ AutoTryWriteLock autol3(l2);
+
+ EXPECT_TRUE(autol3);
+ }
+
+ EXPECT_TRUE(autol1);
+ EXPECT_FALSE(autol2);
+ }
+
+ {
+ AutoReadLock autol4(l1);
+
+ AutoTryWriteLock autol5(l1);
+ EXPECT_FALSE(autol5);
+
+ EXPECT_FALSE(RunOnBackgroundThread([&] {
+ AutoTryWriteLock lock(l1);
+ return !!lock;
+ }));
+ }
+
+ {
+ AutoWriteLock autol6(l1);
+ MOZ_ASSERT(l1.LockedForWritingByCurrentThread());
+
+ AutoTryWriteLock autol7(l1);
+ EXPECT_FALSE(autol7);
+
+ EXPECT_FALSE(RunOnBackgroundThread([&] {
+ AutoTryWriteLock lock(l1);
+ return !!lock;
+ }));
+ }
+
+ AutoTryWriteLock autol8(l1);
+ EXPECT_TRUE(autol8);
+}