1 /* 2 * Copyright (c) Meta Platforms, Inc. and affiliates. 3 * All rights reserved. 4 * 5 * This source code is licensed under both the BSD-style license (found in the 6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found 7 * in the COPYING file in the root directory of this source tree). 8 */ 9 #pragma once 10 11 #include <atomic> 12 #include <cassert> 13 #include <stdexcept> 14 #include <string> 15 16 namespace pzstd { 17 18 // Coordinates graceful shutdown of the pzstd pipeline 19 class ErrorHolder { 20 std::atomic<bool> error_; 21 std::string message_; 22 23 public: 24 ErrorHolder() : error_(false) {} 25 26 bool hasError() noexcept { 27 return error_.load(); 28 } 29 30 void setError(std::string message) noexcept { 31 // Given multiple possibly concurrent calls, exactly one will ever succeed. 32 bool expected = false; 33 if (error_.compare_exchange_strong(expected, true)) { 34 message_ = std::move(message); 35 } 36 } 37 38 bool check(bool predicate, std::string message) noexcept { 39 if (!predicate) { 40 setError(std::move(message)); 41 } 42 return !hasError(); 43 } 44 45 std::string getError() noexcept { 46 error_.store(false); 47 return std::move(message_); 48 } 49 50 ~ErrorHolder() { 51 assert(!hasError()); 52 } 53 }; 54 } 55