diff osx/include/kj/time.h @ 62:0994c39f1e94

Cap'n Proto v0.6 + build for OSX

--- a/osx/include/kj/time.h	Mon Mar 06 13:29:58 2017 +0000
+++ b/osx/include/kj/time.h	Mon May 22 10:01:37 2017 +0100
@@ -1,119 +1,174 @@
-// Copyright (c) 2014 Google Inc. (contributed by Remy Blank <[e-mail]>)
-// Copyright (c) 2013-2014 Sandstorm Development Group, Inc. and contributors
-// Licensed under the MIT License:
-//
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-#ifndef KJ_TIME_H_
-#define KJ_TIME_H_
-
-#if defined(__GNUC__) && !KJ_HEADER_WARNINGS
-#pragma GCC system_header
-#endif
-
-#include "async.h"
-#include "units.h"
-#include <inttypes.h>
-
-namespace kj {
-namespace _ {  // private
-
-class NanosecondLabel;
-class TimeLabel;
-class DateLabel;
-
-}  // namespace _ (private)
-
-using Duration = Quantity<int64_t, _::NanosecondLabel>;
-// A time value, in microseconds.
-
-constexpr Duration NANOSECONDS = unit<Duration>();
-constexpr Duration MICROSECONDS = 1000 * NANOSECONDS;
-constexpr Duration MILLISECONDS = 1000 * MICROSECONDS;
-constexpr Duration SECONDS = 1000 * MILLISECONDS;
-constexpr Duration MINUTES = 60 * SECONDS;
-constexpr Duration HOURS = 60 * MINUTES;
-constexpr Duration DAYS = 24 * HOURS;
-
-using TimePoint = Absolute<Duration, _::TimeLabel>;
-// An absolute time measured by some particular instance of `Timer`.  `Time`s from two different
-// `Timer`s may be measured from different origins and so are not necessarily compatible.
-
-using Date = Absolute<Duration, _::DateLabel>;
-// A point in real-world time, measured relative to the Unix epoch (Jan 1, 1970 00:00:00 UTC).
-
-constexpr Date UNIX_EPOCH = origin<Date>();
-// The `Date` representing Jan 1, 1970 00:00:00 UTC.
-
-class Timer {
-  // Interface to time and timer functionality.
-  //
-  // Each `Timer` may have a different origin, and some `Timer`s may in fact tick at a different
-  // rate than real time (e.g. a `Timer` could represent CPU time consumed by a thread).  However,
-  // all `Timer`s are monotonic: time will never appear to move backwards, even if the calendar
-  // date as tracked by the system is manually modified.
-
-public:
-  virtual TimePoint now() = 0;
-  // Returns the current value of a clock that moves steadily forward, independent of any
-  // changes in the wall clock. The value is updated every time the event loop waits,
-  // and is constant in-between waits.
-
-  virtual Promise<void> atTime(TimePoint time) = 0;
-  // Returns a promise that returns as soon as now() >= time.
-
-  virtual Promise<void> afterDelay(Duration delay) = 0;
-  // Equivalent to atTime(now() + delay).
-
-  template <typename T>
-  Promise<T> timeoutAt(TimePoint time, Promise<T>&& promise) KJ_WARN_UNUSED_RESULT;
-  // Return a promise equivalent to `promise` but which throws an exception (and cancels the
-  // original promise) if it hasn't completed by `time`. The thrown exception is of type
-  // "OVERLOADED".
-
-  template <typename T>
-  Promise<T> timeoutAfter(Duration delay, Promise<T>&& promise) KJ_WARN_UNUSED_RESULT;
-  // Return a promise equivalent to `promise` but which throws an exception (and cancels the
-  // original promise) if it hasn't completed after `delay` from now. The thrown exception is of
-  // type "OVERLOADED".
-
-private:
-  static kj::Exception makeTimeoutException();
-};
-
-// =======================================================================================
-// inline implementation details
-
-template <typename T>
-Promise<T> Timer::timeoutAt(TimePoint time, Promise<T>&& promise) {
-  return promise.exclusiveJoin(atTime(time).then([]() -> kj::Promise<T> {
-    return makeTimeoutException();
-  }));
-}
-
-template <typename T>
-Promise<T> Timer::timeoutAfter(Duration delay, Promise<T>&& promise) {
-  return promise.exclusiveJoin(afterDelay(delay).then([]() -> kj::Promise<T> {
-    return makeTimeoutException();
-  }));
-}
-
-}  // namespace kj
-
-#endif  // KJ_TIME_H_
+// Copyright (c) 2014 Google Inc. (contributed by Remy Blank <[e-mail]>)
+// Copyright (c) 2013-2014 Sandstorm Development Group, Inc. and contributors
+// Licensed under the MIT License:
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+#ifndef KJ_TIME_H_
+#define KJ_TIME_H_
+
+#if defined(__GNUC__) && !KJ_HEADER_WARNINGS
+#pragma GCC system_header
+#endif
+
+#include "async.h"
+#include "units.h"
+#include <inttypes.h>
+
+namespace kj {
+namespace _ {  // private
+
+class NanosecondLabel;
+class TimeLabel;
+class DateLabel;
+
+}  // namespace _ (private)
+
+using Duration = Quantity<int64_t, _::NanosecondLabel>;
+// A time value, in nanoseconds.
+
+constexpr Duration NANOSECONDS = unit<Duration>();
+constexpr Duration MICROSECONDS = 1000 * NANOSECONDS;
+constexpr Duration MILLISECONDS = 1000 * MICROSECONDS;
+constexpr Duration SECONDS = 1000 * MILLISECONDS;
+constexpr Duration MINUTES = 60 * SECONDS;
+constexpr Duration HOURS = 60 * MINUTES;
+constexpr Duration DAYS = 24 * HOURS;
+
+using TimePoint = Absolute<Duration, _::TimeLabel>;
+// An absolute time measured by some particular instance of `Timer`.  `Time`s from two different
+// `Timer`s may be measured from different origins and so are not necessarily compatible.
+
+using Date = Absolute<Duration, _::DateLabel>;
+// A point in real-world time, measured relative to the Unix epoch (Jan 1, 1970 00:00:00 UTC).
+
+constexpr Date UNIX_EPOCH = origin<Date>();
+// The `Date` representing Jan 1, 1970 00:00:00 UTC.
+
+class Clock {
+  // Interface to read the current date and time.
+public:
+  virtual Date now() = 0;
+};
+
+Clock& nullClock();
+// A clock which always returns UNIX_EPOCH as the current time. Useful when you don't care about
+// time.
+
+class Timer {
+  // Interface to time and timer functionality.
+  //
+  // Each `Timer` may have a different origin, and some `Timer`s may in fact tick at a different
+  // rate than real time (e.g. a `Timer` could represent CPU time consumed by a thread).  However,
+  // all `Timer`s are monotonic: time will never appear to move backwards, even if the calendar
+  // date as tracked by the system is manually modified.
+
+public:
+  virtual TimePoint now() = 0;
+  // Returns the current value of a clock that moves steadily forward, independent of any
+  // changes in the wall clock. The value is updated every time the event loop waits,
+  // and is constant in-between waits.
+
+  virtual Promise<void> atTime(TimePoint time) = 0;
+  // Returns a promise that returns as soon as now() >= time.
+
+  virtual Promise<void> afterDelay(Duration delay) = 0;
+  // Equivalent to atTime(now() + delay).
+
+  template <typename T>
+  Promise<T> timeoutAt(TimePoint time, Promise<T>&& promise) KJ_WARN_UNUSED_RESULT;
+  // Return a promise equivalent to `promise` but which throws an exception (and cancels the
+  // original promise) if it hasn't completed by `time`. The thrown exception is of type
+  // "OVERLOADED".
+
+  template <typename T>
+  Promise<T> timeoutAfter(Duration delay, Promise<T>&& promise) KJ_WARN_UNUSED_RESULT;
+  // Return a promise equivalent to `promise` but which throws an exception (and cancels the
+  // original promise) if it hasn't completed after `delay` from now. The thrown exception is of
+  // type "OVERLOADED".
+
+private:
+  static kj::Exception makeTimeoutException();
+};
+
+class TimerImpl final: public Timer {
+  // Implementation of Timer that expects an external caller -- usually, the EventPort
+  // implementation -- to tell it when time has advanced.
+
+public:
+  TimerImpl(TimePoint startTime);
+  ~TimerImpl() noexcept(false);
+
+  Maybe<TimePoint> nextEvent();
+  // Returns the time at which the next scheduled timer event will occur, or null if no timer
+  // events are scheduled.
+
+  Maybe<uint64_t> timeoutToNextEvent(TimePoint start, Duration unit, uint64_t max);
+  // Convenience method which computes a timeout value to pass to an event-waiting system call to
+  // cause it to time out when the next timer event occurs.
+  //
+  // `start` is the time at which the timeout starts counting. This is typically not the same as
+  // now() since some time may have passed since the last time advanceTo() was called.
+  //
+  // `unit` is the time unit in which the timeout is measured. This is often MILLISECONDS. Note
+  // that this method will fractional values *up*, to guarantee that the returned timeout waits
+  // until just *after* the time the event is scheduled.
+  //
+  // The timeout will be clamped to `max`. Use this to avoid an overflow if e.g. the OS wants a
+  // 32-bit value or a signed value.
+  //
+  // Returns nullptr if there are no future events.
+
+  void advanceTo(TimePoint newTime);
+  // Set the time to `time` and fire any at() events that have been passed.
+
+  // implements Timer ----------------------------------------------------------
+  TimePoint now() override;
+  Promise<void> atTime(TimePoint time) override;
+  Promise<void> afterDelay(Duration delay) override;
+
+private:
+  struct Impl;
+  class TimerPromiseAdapter;
+  TimePoint time;
+  Own<Impl> impl;
+};
+
+// =======================================================================================
+// inline implementation details
+
+template <typename T>
+Promise<T> Timer::timeoutAt(TimePoint time, Promise<T>&& promise) {
+  return promise.exclusiveJoin(atTime(time).then([]() -> kj::Promise<T> {
+    return makeTimeoutException();
+  }));
+}
+
+template <typename T>
+Promise<T> Timer::timeoutAfter(Duration delay, Promise<T>&& promise) {
+  return promise.exclusiveJoin(afterDelay(delay).then([]() -> kj::Promise<T> {
+    return makeTimeoutException();
+  }));
+}
+
+inline TimePoint TimerImpl::now() { return time; }
+
+}  // namespace kj
+
+#endif  // KJ_TIME_H_