1 | /* |
2 | * Copyright (c) Facebook, Inc. and its affiliates. |
3 | * |
4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
5 | * you may not use this file except in compliance with the License. |
6 | * You may obtain a copy of the License at |
7 | * |
8 | * http://www.apache.org/licenses/LICENSE-2.0 |
9 | * |
10 | * Unless required by applicable law or agreed to in writing, software |
11 | * distributed under the License is distributed on an "AS IS" BASIS, |
12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
13 | * See the License for the specific language governing permissions and |
14 | * limitations under the License. |
15 | */ |
16 | |
17 | #pragma once |
18 | #include <folly/experimental/TimerFD.h> |
19 | #include <folly/io/async/DelayedDestruction.h> |
20 | #include <map> |
21 | |
22 | namespace folly { |
23 | // generic TimerFD based timeout manager |
24 | class TimerFDTimeoutManager : public TimerFD { |
25 | public: |
26 | using UniquePtr = |
27 | std::unique_ptr<TimerFDTimeoutManager, DelayedDestruction::Destructor>; |
28 | using SharedPtr = std::shared_ptr<TimerFDTimeoutManager>; |
29 | |
30 | public: |
31 | class Callback |
32 | : public boost::intrusive::list_base_hook< |
33 | boost::intrusive::link_mode<boost::intrusive::auto_unlink>> { |
34 | public: |
35 | Callback() = default; |
36 | explicit Callback(TimerFDTimeoutManager* mgr) : mgr_(mgr) {} |
37 | virtual ~Callback() = default; |
38 | |
39 | virtual void timeoutExpired() noexcept = 0; |
40 | virtual void callbackCanceled() noexcept { |
41 | timeoutExpired(); |
42 | } |
43 | |
44 | const std::chrono::microseconds& getExpirationTime() const { |
45 | return expirationTime_; |
46 | } |
47 | |
48 | void setExpirationTime( |
49 | TimerFDTimeoutManager* mgr, |
50 | const std::chrono::microseconds& expirationTime) { |
51 | mgr_ = mgr; |
52 | expirationTime_ = expirationTime; |
53 | } |
54 | |
55 | std::chrono::microseconds getTimeRemaining() const { |
56 | return getTimeRemaining(std::chrono::steady_clock::now()); |
57 | } |
58 | |
59 | std::chrono::microseconds getTimeRemaining( |
60 | std::chrono::steady_clock::time_point now) const { |
61 | auto nowMs = std::chrono::duration_cast<std::chrono::microseconds>( |
62 | now.time_since_epoch()); |
63 | if (expirationTime_ > nowMs) { |
64 | return std::chrono::duration_cast<std::chrono::microseconds>( |
65 | expirationTime_ - nowMs); |
66 | } |
67 | |
68 | return std::chrono::microseconds(0); |
69 | } |
70 | |
71 | void scheduleTimeout(std::chrono::microseconds timeout) { |
72 | if (mgr_) { |
73 | mgr_->scheduleTimeout(this, timeout); |
74 | } |
75 | } |
76 | |
77 | bool cancelTimeout() { |
78 | return mgr_->cancelTimeout(this); |
79 | } |
80 | |
81 | private: |
82 | TimerFDTimeoutManager* mgr_{nullptr}; |
83 | std::chrono::microseconds expirationTime_{0}; |
84 | }; |
85 | |
86 | explicit TimerFDTimeoutManager(folly::EventBase* eventBase); |
87 | ~TimerFDTimeoutManager() override; |
88 | |
89 | // from TimerFD |
90 | void onTimeout() noexcept final; |
91 | |
92 | size_t cancelAll(); |
93 | void scheduleTimeout(Callback* callback, std::chrono::microseconds timeout); |
94 | bool cancelTimeout(Callback* callback); |
95 | |
96 | template <class F> |
97 | void scheduleTimeoutFn(F fn, std::chrono::microseconds timeout) { |
98 | struct Wrapper : Callback { |
99 | explicit Wrapper(F f) : fn_(std::move(f)) {} |
100 | void timeoutExpired() noexcept override { |
101 | try { |
102 | fn_(); |
103 | } catch (std::exception const& e) { |
104 | LOG(ERROR) << "HHWheelTimerBase timeout callback threw an exception: " |
105 | << e.what(); |
106 | } catch (...) { |
107 | LOG(ERROR) |
108 | << "HHWheelTimerBase timeout callback threw a non-exception." ; |
109 | } |
110 | delete this; |
111 | } |
112 | F fn_; |
113 | }; |
114 | Wrapper* w = new Wrapper(std::move(fn)); |
115 | scheduleTimeout(w, timeout); |
116 | } |
117 | |
118 | size_t count() const; |
119 | |
120 | private: |
121 | void processExpiredTimers(); |
122 | void scheduleNextTimer(); |
123 | |
124 | std::chrono::steady_clock::time_point getCurTime() { |
125 | return std::chrono::steady_clock::now(); |
126 | } |
127 | |
128 | // we can attempt to schedule new entries while in processExpiredTimers |
129 | // we want to reschedule the timers once we're done with the processing |
130 | bool processingExpired_{false}; |
131 | |
132 | typedef boost::intrusive:: |
133 | list<Callback, boost::intrusive::constant_time_size<false>> |
134 | CallbackList; |
135 | std::map<std::chrono::microseconds, CallbackList> callbacks_; |
136 | CallbackList inProgressList_; |
137 | }; |
138 | } // namespace folly |
139 | |