--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/CSP2/CSP2_env/env-d9b9114564458d9d-741b3de822f2aaca6c6caa4325c4afce/include/kj/timer.h	Tue Mar 18 17:55:14 2025 -0400
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+// Copyright (c) 2014 Google Inc. (contributed by Remy Blank <rblank@google.com>)
+// 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.
+
+#pragma once
+
+#include <kj/time.h>
+#include "async.h"
+
+KJ_BEGIN_HEADER
+
+namespace kj {
+
+class Timer: public MonotonicClock {
+  // 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.
+  //
+  // That said, the `Timer` returned by `kj::setupAsyncIo().provider->getTimer()` in particular is
+  // guaranteed to be synchronized with the `MonotonicClock` returned by
+  // `systemPreciseMonotonicClock()` (or, more precisely, is updated to match that clock whenever
+  // the loop waits).
+  //
+  // Note that the value returned by `Timer::now()` only changes each time the
+  // event loop waits for I/O from the system. While the event loop is actively
+  // running, the time stays constant. This is intended to make behavior more
+  // deterministic and reproducible. However, if you need up-to-the-cycle
+  // accurate time, then `Timer::now()` is not appropriate. Instead, use
+  // `systemPreciseMonotonicClock()` directly in this case.
+
+public:
+  virtual TimePoint now() const = 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() const 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() const { return time; }
+
+}  // namespace kj
+
+KJ_END_HEADER