gecko-dev/js/ipc/CPOWTimer.cpp

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * vim: set ts=4 sw=4 et tw=80:
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "jsfriendapi.h"
#include "nsContentUtils.h"
#include "CPOWTimer.h"

#include "jsapi.h"

CPOWTimer::CPOWTimer(JSContext* cx MOZ_GUARD_OBJECT_NOTIFIER_PARAM_IN_IMPL)
    : cx_(nullptr)
    , startInterval_(0)
{
    MOZ_GUARD_OBJECT_NOTIFIER_INIT;
    if (!js::GetStopwatchIsMonitoringCPOW(cx))
        return;
    cx_ = cx;
    startInterval_ = JS_Now();
}
CPOWTimer::~CPOWTimer()
{
    if (!cx_) {
        // Monitoring was off when we started the timer.
        return;
    }

    if (!js::GetStopwatchIsMonitoringCPOW(cx_)) {
        // Monitoring has been deactivated while we were in the timer.
        return;
    }

    const int64_t endInterval = JS_Now();
    if (endInterval <= startInterval_) {
        // Do not assume monotonicity.
        return;
    }

    js::AddCPOWPerformanceDelta(cx_, endInterval - startInterval_);
}