1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/public/SliceBudget.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,57 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.5 + * vim: set ts=8 sts=4 et sw=4 tw=99:
1.6 + * This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef js_SliceBudget_h
1.11 +#define js_SliceBudget_h
1.12 +
1.13 +#include <stdint.h>
1.14 +
1.15 +namespace js {
1.16 +
1.17 +/*
1.18 + * This class records how much work has been done in a given collection slice, so that
1.19 + * we can return before pausing for too long. Some slices are allowed to run for
1.20 + * unlimited time, and others are bounded. To reduce the number of gettimeofday
1.21 + * calls, we only check the time every 1000 operations.
1.22 + */
1.23 +struct JS_PUBLIC_API(SliceBudget)
1.24 +{
1.25 + int64_t deadline; /* in microseconds */
1.26 + intptr_t counter;
1.27 +
1.28 + static const intptr_t CounterReset = 1000;
1.29 +
1.30 + static const int64_t Unlimited = 0;
1.31 + static int64_t TimeBudget(int64_t millis);
1.32 + static int64_t WorkBudget(int64_t work);
1.33 +
1.34 + /* Equivalent to SliceBudget(UnlimitedBudget). */
1.35 + SliceBudget();
1.36 +
1.37 + /* Instantiate as SliceBudget(Time/WorkBudget(n)). */
1.38 + SliceBudget(int64_t budget);
1.39 +
1.40 + void reset() {
1.41 + deadline = INT64_MAX;
1.42 + counter = INTPTR_MAX;
1.43 + }
1.44 +
1.45 + void step(intptr_t amt = 1) {
1.46 + counter -= amt;
1.47 + }
1.48 +
1.49 + bool checkOverBudget();
1.50 +
1.51 + bool isOverBudget() {
1.52 + if (counter >= 0)
1.53 + return false;
1.54 + return checkOverBudget();
1.55 + }
1.56 +};
1.57 +
1.58 +} // namespace js
1.59 +
1.60 +#endif /* js_SliceBudget_h */
