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-rw-r--r-- | src/seastar/include/seastar/util/alloc_failure_injector.hh | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/src/seastar/include/seastar/util/alloc_failure_injector.hh b/src/seastar/include/seastar/util/alloc_failure_injector.hh new file mode 100644 index 000000000..fc43b4dc3 --- /dev/null +++ b/src/seastar/include/seastar/util/alloc_failure_injector.hh @@ -0,0 +1,132 @@ +/* + * This file is open source software, licensed to you under the terms + * of the Apache License, Version 2.0 (the "License"). See the NOTICE file + * distributed with this work for additional information regarding copyright + * ownership. You may not use this file except in compliance with the License. + * + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ +/* + * Copyright 2017 ScyllaDB + */ + +#pragma once + +#include <limits> +#include <cstdint> +#include <functional> +#include <seastar/util/noncopyable_function.hh> +#include <seastar/util/critical_alloc_section.hh> + +namespace seastar { +namespace memory { + +/// +/// Allocation failure injection framework. Allows testing for exception safety. +/// +/// To exhaustively inject failure at every allocation point: +/// +/// uint64_t i = 0; +/// while (true) { +/// try { +/// local_failure_injector().fail_after(i++); +/// code_under_test(); +/// local_failure_injector().cancel(); +/// break; +/// } catch (const std::bad_alloc&) { +/// // expected +/// } +/// } +class alloc_failure_injector { + uint64_t _alloc_count; + uint64_t _fail_at = std::numeric_limits<uint64_t>::max(); + noncopyable_function<void()> _on_alloc_failure = [] { throw std::bad_alloc(); }; + bool _failed; +private: + void fail(); +public: + /// \brief Marks a point in code which should be considered for failure injection. + void on_alloc_point() { + if (is_critical_alloc_section()) { + return; + } + if (_alloc_count >= _fail_at) { + fail(); + } + ++_alloc_count; + } + + /// Counts encountered allocation points which didn't fail and didn't have failure suppressed. + uint64_t alloc_count() const { + return _alloc_count; + } + + /// Will cause count-th allocation point from now to fail, counting from 0. + void fail_after(uint64_t count) { + _fail_at = _alloc_count + count; + _failed = false; + } + + /// Cancels the failure scheduled by fail_after(). + void cancel() { + _fail_at = std::numeric_limits<uint64_t>::max(); + } + + /// Returns true iff allocation was failed since last fail_after(). + bool failed() const { + return _failed; + } + + /// Runs given function with a custom failure action instead of the default std::bad_alloc throw. + void run_with_callback(noncopyable_function<void()> callback, noncopyable_function<void()> to_run); +}; + +/// \cond internal +extern thread_local alloc_failure_injector the_alloc_failure_injector; +/// \endcond + +/// \brief Return the shard-local \ref alloc_failure_injector instance. +inline +alloc_failure_injector& local_failure_injector() { + return the_alloc_failure_injector; +} + +#ifdef SEASTAR_ENABLE_ALLOC_FAILURE_INJECTION + +#ifdef SEASTAR_DEFAULT_ALLOCATOR +#error SEASTAR_ENABLE_ALLOC_FAILURE_INJECTION is not supported when using SEASTAR_DEFAULT_ALLOCATOR +#endif + +#endif + + +struct [[deprecated("Use scoped_critical_section instead")]] disable_failure_guard { + scoped_critical_alloc_section cs; +}; + +/// \brief Marks a point in code which should be considered for failure injection. +inline +void on_alloc_point() { +#ifdef SEASTAR_ENABLE_ALLOC_FAILURE_INJECTION + local_failure_injector().on_alloc_point(); +#endif +} + +/// Repeatedly run func with allocation failures +/// +/// Initially, allocations start to fail immediately. In each +/// subsequent run the failures start one allocation later. This +/// returns when func is run and no allocation failures are detected. +void with_allocation_failures(noncopyable_function<void()> func); + +} +} |