зеркало из https://github.com/mozilla/gecko-dev.git
67 строки
1.7 KiB
C++
67 строки
1.7 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
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* vim: set ts=8 sts=4 et sw=4 tw=99:
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#ifndef js_SliceBudget_h
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#define js_SliceBudget_h
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#include <stdint.h>
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namespace js {
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/*
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* This class records how much work has been done in a given collection slice, so that
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* we can return before pausing for too long. Some slices are allowed to run for
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* unlimited time, and others are bounded. To reduce the number of gettimeofday
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* calls, we only check the time every 1000 operations.
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*/
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struct JS_PUBLIC_API(SliceBudget)
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{
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int64_t deadline; /* in microseconds */
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intptr_t counter;
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static const intptr_t CounterReset = 1000;
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static const int64_t Unlimited = 0;
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static int64_t TimeBudget(int64_t millis);
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static int64_t WorkBudget(int64_t work);
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/* Equivalent to SliceBudget(UnlimitedBudget). */
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SliceBudget();
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/* Instantiate as SliceBudget(Time/WorkBudget(n)). */
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SliceBudget(int64_t budget);
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void reset() {
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deadline = unlimitedDeadline;
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counter = unlimitedStartCounter;
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}
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void step(intptr_t amt = 1) {
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counter -= amt;
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}
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bool checkOverBudget();
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bool isOverBudget() {
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if (counter >= 0)
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return false;
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return checkOverBudget();
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}
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bool isUnlimited() {
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return deadline == unlimitedDeadline;
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}
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private:
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static const int64_t unlimitedDeadline = INT64_MAX;
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static const intptr_t unlimitedStartCounter = INTPTR_MAX;
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};
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} // namespace js
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#endif /* js_SliceBudget_h */
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