Kea  2.1.7-git
interval_timer.cc
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1 // Copyright (C) 2011-2020 Internet Systems Consortium, Inc. ("ISC")
2 //
3 // This Source Code Form is subject to the terms of the Mozilla Public
4 // License, v. 2.0. If a copy of the MPL was not distributed with this
5 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
6 
7 #include <config.h>
10 #include <asiolink/io_service.h>
11 
12 #include <boost/enable_shared_from_this.hpp>
13 #include <boost/noncopyable.hpp>
14 #include <boost/shared_ptr.hpp>
15 
16 #include <exceptions/exceptions.h>
17 
18 #include <atomic>
19 #include <functional>
20 #include <mutex>
21 
22 using namespace std;
23 namespace ph = std::placeholders;
24 
25 namespace isc {
26 namespace asiolink {
27 
36  public boost::enable_shared_from_this<IntervalTimerImpl>,
37  public boost::noncopyable {
38 public:
39 
43  IntervalTimerImpl(IOService& io_service);
44 
47 
53  void setup(const IntervalTimer::Callback& cbfunc, const long interval,
54  const IntervalTimer::Mode& interval_mode
55  = IntervalTimer::REPEATING);
56 
60  void callback(const boost::system::error_code& error);
61 
63  void cancel() {
64  lock_guard<mutex> lk (mutex_);
65  timer_.cancel();
66  interval_ = 0;
67  }
68 
72  long getInterval() const { return (interval_); }
73 
74 private:
75 
79  void update();
80 
83 
85  std::atomic<long> interval_;
86 
88  boost::asio::deadline_timer timer_;
89 
92 
94  std::mutex mutex_;
95 
100  static const long INVALIDATED_INTERVAL = -1;
101 };
102 
103 IntervalTimerImpl::IntervalTimerImpl(IOService& io_service) :
104  interval_(0), timer_(io_service.get_io_service()),
105  mode_(IntervalTimer::REPEATING) {
106 }
107 
109  interval_ = INVALIDATED_INTERVAL;
110 }
111 
112 void
114  const long interval,
115  const IntervalTimer::Mode& mode) {
116  // Interval should not be less than 0.
117  if (interval < 0) {
118  isc_throw(isc::BadValue, "Interval should not be less than or "
119  "equal to 0");
120  }
121  // Call back function should not be empty.
122  if (!cbfunc) {
123  isc_throw(isc::InvalidParameter, "Callback function is empty");
124  }
125 
126  lock_guard<mutex> lk(mutex_);
127  cbfunc_ = cbfunc;
128  interval_ = interval;
129  mode_ = mode;
130 
131  // Set initial expire time.
132  // At this point the timer is not running yet and will not expire.
133  // After calling IOService::run(), the timer will expire.
134  update();
135 }
136 
137 void
138 IntervalTimerImpl::update() {
139  try {
140  // Update expire time to (current time + interval_).
141  timer_.expires_from_now(boost::posix_time::millisec(long(interval_)));
142  // Reset timer.
143  // Pass a function bound with a shared_ptr to this.
144  timer_.async_wait(std::bind(&IntervalTimerImpl::callback,
145  shared_from_this(),
146  ph::_1)); //error
147  } catch (const boost::system::system_error& e) {
148  isc_throw(isc::Unexpected, "Failed to update timer: " << e.what());
149  } catch (const boost::bad_weak_ptr&) {
150  // Can't happen. It means a severe internal bug.
151  }
152 }
153 
154 void
155 IntervalTimerImpl::callback(const boost::system::error_code& ec) {
156  if (interval_ == INVALIDATED_INTERVAL) {
157  isc_throw(isc::BadValue, "Interval internal state");
158  }
159  if (interval_ == 0 || ec) {
160  // timer has been canceled. Do nothing.
161  } else {
162  {
163  lock_guard<mutex> lk(mutex_);
164  // If we should repeat, set next expire time.
165  if (mode_ == IntervalTimer::REPEATING) {
166  update();
167  }
168  }
169 
170  // Invoke the call back function.
171  cbfunc_();
172  }
173 }
174 
175 IntervalTimer::IntervalTimer(IOService& io_service) :
176  impl_(new IntervalTimerImpl(io_service)) {
177 }
178 
180  // Cancel the timer to make sure cbfunc_() will not be called any more.
181  cancel();
182 }
183 
184 void
185 IntervalTimer::setup(const Callback& cbfunc, const long interval,
186  const IntervalTimer::Mode& mode) {
187  return (impl_->setup(cbfunc, interval, mode));
188 }
189 
190 void
192  impl_->cancel();
193 }
194 
195 long
197  return (impl_->getInterval());
198 }
199 
200 } // namespace asiolink
201 } // namespace isc
CompressMode mode_
Definition: rdatafields.cc:97
A generic exception that is thrown if a parameter given to a method or function is considered invalid...
STL namespace.
virtual const char * what() const
Returns a C-style character string of the cause of the exception.
#define isc_throw(type, stream)
A shortcut macro to insert known values into exception arguments.
A generic exception that is thrown if a parameter given to a method is considered invalid in that con...
A generic exception that is thrown when an unexpected error condition occurs.
Defines the logger used by the top-level component of kea-lfc.