rocksdb/util/defer_test.cc
Cheng Chang dafb568052 Add utility class Defer (#6382)
Summary:
Add a utility class `Defer` to defer the execution of a function until the Defer object goes out of scope.
Used in VersionSet:: ProcessManifestWrites as an example.
The inline comments for class `Defer` have more details.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6382

Test Plan: `make defer_test version_set_test && ./defer_test && ./version_set_test`

Differential Revision: D19797538

Pulled By: cheng-chang

fbshipit-source-id: b1a9b7306e4fd4f48ec2ab55783caa561a315f0f
2020-02-10 17:59:47 -08:00

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849 B
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// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#include "port/port.h"
#include "port/stack_trace.h"
#include "test_util/testharness.h"
#include "util/defer.h"
namespace rocksdb {
class DeferTest {};
TEST(DeferTest, BlockScope) {
int v = 1;
{
Defer defer([&v]() { v *= 2; });
}
ASSERT_EQ(2, v);
}
TEST(DeferTest, FunctionScope) {
int v = 1;
auto f = [&v]() {
Defer defer([&v]() { v *= 2; });
v = 2;
};
f();
ASSERT_EQ(4, v);
}
} // namespace rocksdb
int main(int argc, char** argv) {
rocksdb::port::InstallStackTraceHandler();
::testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}