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diff --git a/src/mongo/util/cancellation_test.cpp b/src/mongo/util/cancellation_test.cpp
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+++ b/src/mongo/util/cancellation_test.cpp
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+/**
+ *    Copyright (C) 2020-present MongoDB, Inc.
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the Server Side Public License, version 1,
+ *    as published by MongoDB, Inc.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    Server Side Public License for more details.
+ *
+ *    You should have received a copy of the Server Side Public License
+ *    along with this program. If not, see
+ *    <http://www.mongodb.com/licensing/server-side-public-license>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the Server Side Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
+
+#include "mongo/platform/basic.h"
+
+#include "mongo/unittest/death_test.h"
+#include "mongo/unittest/unittest.h"
+#include "mongo/util/cancellation.h"
+
+namespace mongo {
+namespace {
+
+TEST(CancelTest, CancelSourceDestructorDoesNotCauseCancellation) {
+    bool ran{false};
+    {
+        CancellationSource source;
+        source.token().onCancel().unsafeToInlineFuture().getAsync([&ran](Status s) mutable {
+            ASSERT_EQ(s, detail::getCancelNeverCalledOnSourceError());
+            ran = true;
+        });
+    }
+
+    ASSERT_TRUE(ran);
+}
+
+TEST(CancelTest, CancelTokenIsCanceledIsFalseBeforeCancellation) {
+    CancellationSource source;
+    ASSERT_FALSE(source.token().isCanceled());
+}
+
+TEST(CancelTest, CancelTokenOnCancelFutureIsNotReadyBeforeCancellation) {
+    CancellationSource source;
+    ASSERT_FALSE(source.token().onCancel().isReady());
+}
+
+TEST(CancelTest, CancelingSourceMakesExistingCancelTokenIsCanceledTrue) {
+    CancellationSource source;
+    auto token = source.token();
+    source.cancel();
+    ASSERT_TRUE(token.isCanceled());
+}
+
+TEST(CancelTest, CancelingSourceMakesCancelTokenIsCanceledTrueForTokensCreatedAfterCancellation) {
+    CancellationSource source;
+    source.cancel();
+    ASSERT_TRUE(source.token().isCanceled());
+}
+
+TEST(CancelTest, CallingCancelOnCancellationSourceTwiceIsSafe) {
+    CancellationSource source;
+    source.cancel();
+    source.cancel();
+    ASSERT_TRUE(source.token().isCanceled());
+}
+
+TEST(CancelTest,
+     CallingCancelOnACopyOfACancellationSourceTriggersCancellationInTokensObtainedFromOriginal) {
+    CancellationSource source;
+    auto token = source.token();
+    auto copy = source;
+    copy.cancel();
+    ASSERT_TRUE(token.isCanceled());
+}
+
+TEST(CancelTest,
+     DestroyingACopyOfACancellationSourceDoesNotSetErrorOnCancellationFutureFromOriginalSource) {
+    CancellationSource source;
+    auto token = source.token();
+    { auto copy = source; }
+    ASSERT_FALSE(token.onCancel().isReady());
+}
+
+TEST(CancelTest,
+     DestroyingACancellationSourceWithAnExistingCopyDoesNotSetErrorOnCancellationFuture) {
+    boost::optional<CancellationSource> source;
+    source.emplace();
+    auto copy = *source;
+    source.reset();
+    ASSERT_FALSE(copy.token().onCancel().isReady());
+}
+
+TEST(CancelTest, CancelingSourceTriggersOnCancelCallbacksOnSingleCancelToken) {
+    CancellationSource source;
+    auto token = source.token();
+    bool cancelCallbackRan{false};
+    auto result = token.onCancel().unsafeToInlineFuture().then([&] { cancelCallbackRan = true; });
+    source.cancel();
+    result.wait();
+    ASSERT_TRUE(cancelCallbackRan);
+}
+
+TEST(CancelTest, CancelingSourceTriggersOnCancelCallbacksOnMultipleCancelTokens) {
+    CancellationSource source;
+    auto token1 = source.token();
+    auto token2 = source.token();
+    bool cancelCallback1Ran{false};
+    bool cancelCallback2Ran{false};
+    auto result1 =
+        token1.onCancel().unsafeToInlineFuture().then([&] { cancelCallback1Ran = true; });
+    auto result2 =
+        token2.onCancel().unsafeToInlineFuture().then([&] { cancelCallback2Ran = true; });
+    source.cancel();
+    result1.wait();
+    result2.wait();
+    ASSERT_TRUE(cancelCallback1Ran);
+    ASSERT_TRUE(cancelCallback2Ran);
+}
+
+TEST(CancelTest, CancelTokenOnCancelFutureIsReadyAndRunsCallbacksOnTokensCreatedAfterCancellation) {
+    CancellationSource source;
+    source.cancel();
+    bool cancelCallbackRan{false};
+    auto token = source.token();
+    ASSERT_TRUE(token.onCancel().isReady());
+    token.onCancel().unsafeToInlineFuture().then([&] { cancelCallbackRan = true; }).wait();
+    ASSERT_TRUE(cancelCallbackRan);
+}
+
+TEST(CancelTest, CancelingSourceConstructedFromATokenDoesNotCancelThatToken) {
+    CancellationSource parent;
+    auto parentToken = parent.token();
+
+    CancellationSource child(parentToken);
+    child.cancel();
+
+    ASSERT_FALSE(parentToken.isCanceled());
+    ASSERT_TRUE(child.token().isCanceled());
+}
+
+TEST(CancelTest, CancelingTokenUsedToConstructASourceCallsCancelOnThatSource) {
+    CancellationSource parent;
+    CancellationSource child(parent.token());
+    parent.cancel();
+
+    ASSERT_TRUE(parent.token().isCanceled());
+    ASSERT_TRUE(child.token().isCanceled());
+}
+
+TEST(CancelTest, CancelTokenRemembersIsCanceledForCanceledSourceEvenAfterSourceIsDestroyed) {
+    auto token = [] {
+        CancellationSource source;
+        auto token = source.token();
+        source.cancel();
+        return token;
+    }();
+    ASSERT_TRUE(token.isCanceled());
+    ASSERT_TRUE(token.onCancel().isReady());
+    ASSERT_EQ(token.onCancel().getNoThrow(), Status::OK());
+}
+
+TEST(CancelTest, CancelTokenRemembersNotCanceledForNotCanceledSourceEvenAfterSourceIsDestroyed) {
+    auto token = [] {
+        CancellationSource source;
+        auto token = source.token();
+        return token;
+    }();
+    ASSERT_FALSE(token.isCanceled());
+    ASSERT_TRUE(token.onCancel().isReady());
+    ASSERT_EQ(token.onCancel().getNoThrow(), detail::getCancelNeverCalledOnSourceError());
+}
+
+TEST(CancelTest, UncancelableTokenReturnsFalseForIsCanceled) {
+    auto token = CancellationToken::uncancelable();
+    ASSERT_FALSE(token.isCanceled());
+}
+
+TEST(CancelTest, UncancelableTokenNeverRunsCallbacks) {
+    auto token = CancellationToken::uncancelable();
+    auto cancelFuture = token.onCancel();
+    ASSERT_TRUE(cancelFuture.isReady());
+    ASSERT_EQ(cancelFuture.getNoThrow(), detail::getCancelNeverCalledOnSourceError());
+}
+
+TEST(CancelTest, UncancelableTokenReturnsFalseForIsCancelable) {
+    auto token = CancellationToken::uncancelable();
+    ASSERT_FALSE(token.isCancelable());
+}
+
+TEST(CancelTest, TokenIsCancelableReturnsTrueIfSourceIsAlreadyCanceled) {
+    CancellationSource source;
+    auto token = source.token();
+    ASSERT_TRUE(token.isCancelable());
+}
+
+TEST(CancelTest, TokenIsCancelableReturnsFalseIfSourceHasBeenDestroyedWithoutCancelBeingCalled) {
+    auto token = [] {
+        CancellationSource source;
+        auto token = source.token();
+        return token;
+    }();
+    ASSERT_FALSE(token.isCancelable());
+}
+
+TEST(CancelTest, TokenIsCancelableReturnsTrueIfSourceExistsAndIsNotYetCanceled) {
+    CancellationSource source;
+    auto token = source.token();
+    ASSERT_TRUE(token.isCancelable());
+}
+
+}  // namespace
+}  // namespace mongo