Ziele Untersuchung
mit Columbo Integrität von
Datenbanken Interaktion und
Portierbarkeit Ergonomie der
Schnittstellen

Angebot Produkte Projekt Beratung

Mittel Analytik Modellierung Sprachen Algebra Logik Hardware Denken Kreativität

Zusammenhänge Gesellschaft Wirtschaft Branche Firma


products/Sources/formale Sprachen/C/Firefox/xpcom/threads/ (Browser von der Mozilla Stiftung Version 136.0.1^©) Datei vom 10.2.2025 mit Größe 3 kB

Quelle nsMemoryPressure.cpp Sprache: C

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 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 "nsMemoryPressure.h"
#include "mozilla/Assertions.h"
#include "mozilla/Atomics.h"
#include "mozilla/Services.h"

#include "nsThreadUtils.h"
#include "nsIObserverService.h"

using namespace mozilla;

const char* const kTopicMemoryPressure = "memory-pressure";
const char* const kTopicMemoryPressureStop = "memory-pressure-stop";
const char16_t* const kSubTopicLowMemoryNew = u"low-memory";
const char16_t* const kSubTopicLowMemoryOngoing = u"low-memory-ongoing";

// This is accessed from any thread through NS_NotifyOfEventualMemoryPressure
static Atomic<MemoryPressureState, Relaxed> sMemoryPressurePending(
    MemoryPressureState::NoPressure);

void NS_NotifyOfEventualMemoryPressure(MemoryPressureState aState) {
  MOZ_ASSERT(aState != MemoryPressureState::None);

  /*
   * A new memory pressure event erases an ongoing (or stop of) memory pressure,
   * but an existing "new" memory pressure event takes precedence over a new
   * "ongoing" or "stop" memory pressure event.
   */
  switch (aState) {
    case MemoryPressureState::None:
    case MemoryPressureState::LowMemory:
      sMemoryPressurePending = aState;
      break;
    case MemoryPressureState::NoPressure:
      sMemoryPressurePending.compareExchange(MemoryPressureState::None, aState);
      break;
  }
}

nsresult NS_NotifyOfMemoryPressure(MemoryPressureState aState) {
  NS_NotifyOfEventualMemoryPressure(aState);
  nsCOMPtr<nsIRunnable> event =
      new Runnable("NS_DispatchEventualMemoryPressure");
  return NS_DispatchToMainThread(event);
}

void NS_DispatchMemoryPressure() {
  MOZ_ASSERT(NS_IsMainThread());
  static MemoryPressureState sMemoryPressureStatus =
      MemoryPressureState::NoPressure;

  MemoryPressureState mpPending =
      sMemoryPressurePending.exchange(MemoryPressureState::None);
  if (mpPending == MemoryPressureState::None) {
    return;
  }

  nsCOMPtr<nsIObserverService> os = services::GetObserverService();
  if (!os) {
    NS_WARNING("Can't get observer service!");
    return;
  }

  switch (mpPending) {
    case MemoryPressureState::None:
      MOZ_ASSERT_UNREACHABLE("Already handled this case above.");
      break;
    case MemoryPressureState::LowMemory:
      switch (sMemoryPressureStatus) {
        case MemoryPressureState::None:
          MOZ_ASSERT_UNREACHABLE("The internal status should never be None.");
          break;
        case MemoryPressureState::NoPressure:
          sMemoryPressureStatus = MemoryPressureState::LowMemory;
          os->NotifyObservers(nullptr, kTopicMemoryPressure,
                              kSubTopicLowMemoryNew);
          break;
        case MemoryPressureState::LowMemory:
          os->NotifyObservers(nullptr, kTopicMemoryPressure,
                              kSubTopicLowMemoryOngoing);
          break;
      }
      break;
    case MemoryPressureState::NoPressure:
      switch (sMemoryPressureStatus) {
        case MemoryPressureState::None:
          MOZ_ASSERT_UNREACHABLE("The internal status should never be None.");
          break;
        case MemoryPressureState::NoPressure:
          // Already no pressure.  Do nothing.
          break;
        case MemoryPressureState::LowMemory:
          sMemoryPressureStatus = MemoryPressureState::NoPressure;
          os->NotifyObservers(nullptr, kTopicMemoryPressureStop, nullptr);
          break;
      }
      break;
  }
}

quality99%

¤ Dauer der Verarbeitung: 0.13 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.