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/*
* Copyright (C) 2011-2017 Apple Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "MemoryPressureHandler.h"
#include "Logging.h"
#include <wtf/MemoryFootprint.h>
namespace WebCore {
WEBCORE_EXPORT bool MemoryPressureHandler::ReliefLogger::s_loggingEnabled = false;
MemoryPressureHandler& MemoryPressureHandler::singleton()
{
static NeverDestroyed<MemoryPressureHandler> memoryPressureHandler;
return memoryPressureHandler;
}
MemoryPressureHandler::MemoryPressureHandler()
#if OS(LINUX)
: m_holdOffTimer(RunLoop::main(), this, &MemoryPressureHandler::holdOffTimerFired)
#endif
{
}
void MemoryPressureHandler::setShouldUsePeriodicMemoryMonitor(bool use)
{
if (use) {
m_measurementTimer = std::make_unique<RunLoop::Timer<MemoryPressureHandler>>(RunLoop::main(), this, &MemoryPressureHandler::measurementTimerFired);
m_measurementTimer->startRepeating(30);
} else
m_measurementTimer = nullptr;
}
#if !RELEASE_LOG_DISABLED
static const char* toString(MemoryUsagePolicy policy)
{
switch (policy) {
case MemoryUsagePolicy::Unrestricted: return "Unrestricted";
case MemoryUsagePolicy::Conservative: return "Conservative";
case MemoryUsagePolicy::Strict: return "Strict";
case MemoryUsagePolicy::Panic: return "Panic";
}
}
#endif
static size_t thresholdForPolicy(MemoryUsagePolicy policy)
{
switch (policy) {
case MemoryUsagePolicy::Conservative:
return 1 * GB;
case MemoryUsagePolicy::Strict:
return 2 * GB;
case MemoryUsagePolicy::Panic:
#if CPU(X86_64) || CPU(ARM64)
return 4 * GB;
#else
return 3 * GB;
#endif
case MemoryUsagePolicy::Unrestricted:
default:
ASSERT_NOT_REACHED();
return 0;
}
}
static MemoryUsagePolicy policyForFootprint(size_t footprint)
{
if (footprint >= thresholdForPolicy(MemoryUsagePolicy::Panic))
return MemoryUsagePolicy::Panic;
if (footprint >= thresholdForPolicy(MemoryUsagePolicy::Strict))
return MemoryUsagePolicy::Strict;
if (footprint >= thresholdForPolicy(MemoryUsagePolicy::Conservative))
return MemoryUsagePolicy::Conservative;
return MemoryUsagePolicy::Unrestricted;
}
void MemoryPressureHandler::measurementTimerFired()
{
auto footprint = memoryFootprint();
if (!footprint)
return;
RELEASE_LOG(MemoryPressure, "Current memory footprint: %lu MB", footprint.value() / MB);
auto newPolicy = policyForFootprint(footprint.value());
if (newPolicy == m_memoryUsagePolicy) {
if (m_memoryUsagePolicy != MemoryUsagePolicy::Panic)
return;
RELEASE_LOG(MemoryPressure, "Memory usage still above panic threshold");
} else
RELEASE_LOG(MemoryPressure, "Memory usage policy changed: %s -> %s", toString(m_memoryUsagePolicy), toString(newPolicy));
m_memoryUsagePolicy = newPolicy;
if (newPolicy == MemoryUsagePolicy::Unrestricted)
return;
if (newPolicy == MemoryUsagePolicy::Conservative) {
// FIXME: Implement this policy by choosing which caches should respect it, and hooking them up.
return;
}
if (newPolicy == MemoryUsagePolicy::Strict) {
RELEASE_LOG(MemoryPressure, "Attempting to reduce memory footprint by freeing less important objects.");
releaseMemory(Critical::No, Synchronous::No);
return;
}
RELEASE_ASSERT(newPolicy == MemoryUsagePolicy::Panic);
RELEASE_LOG(MemoryPressure, "Attempting to reduce memory footprint by freeing more important objects.");
if (m_processIsEligibleForMemoryKillCallback) {
if (!m_processIsEligibleForMemoryKillCallback()) {
releaseMemory(Critical::Yes, Synchronous::No);
return;
}
}
releaseMemory(Critical::Yes, Synchronous::Yes);
// Remeasure footprint to see how well the pressure handler did.
footprint = memoryFootprint();
RELEASE_ASSERT(footprint);
RELEASE_LOG(MemoryPressure, "New memory footprint: %lu MB", footprint.value() / MB);
if (footprint.value() < thresholdForPolicy(MemoryUsagePolicy::Panic)) {
m_memoryUsagePolicy = policyForFootprint(footprint.value());
RELEASE_LOG(MemoryPressure, "Pressure reduced below panic threshold. New memory usage policy: %s", toString(m_memoryUsagePolicy));
return;
}
if (m_memoryKillCallback)
m_memoryKillCallback();
}
void MemoryPressureHandler::beginSimulatedMemoryPressure()
{
m_isSimulatingMemoryPressure = true;
respondToMemoryPressure(Critical::Yes, Synchronous::Yes);
}
void MemoryPressureHandler::endSimulatedMemoryPressure()
{
m_isSimulatingMemoryPressure = false;
}
void MemoryPressureHandler::releaseMemory(Critical critical, Synchronous synchronous)
{
if (!m_lowMemoryHandler)
return;
ReliefLogger log("Total");
m_lowMemoryHandler(critical, synchronous);
platformReleaseMemory(critical);
}
void MemoryPressureHandler::ReliefLogger::logMemoryUsageChange()
{
#if !RELEASE_LOG_DISABLED
#define STRING_SPECIFICATION "%{public}s"
#define MEMORYPRESSURE_LOG(...) RELEASE_LOG(MemoryPressure, __VA_ARGS__)
#else
#define STRING_SPECIFICATION "%s"
#define MEMORYPRESSURE_LOG(...) WTFLogAlways(__VA_ARGS__)
#endif
auto currentMemory = platformMemoryUsage();
if (!currentMemory || !m_initialMemory) {
MEMORYPRESSURE_LOG("Memory pressure relief: " STRING_SPECIFICATION ": (Unable to get dirty memory information for process)", m_logString);
return;
}
long residentDiff = currentMemory->resident - m_initialMemory->resident;
long physicalDiff = currentMemory->physical - m_initialMemory->physical;
MEMORYPRESSURE_LOG("Memory pressure relief: " STRING_SPECIFICATION ": res = %zu/%zu/%ld, res+swap = %zu/%zu/%ld",
m_logString,
m_initialMemory->resident, currentMemory->resident, residentDiff,
m_initialMemory->physical, currentMemory->physical, physicalDiff);
}
#if !PLATFORM(COCOA) && !OS(LINUX) && !PLATFORM(WIN)
void MemoryPressureHandler::install() { }
void MemoryPressureHandler::uninstall() { }
void MemoryPressureHandler::holdOff(unsigned) { }
void MemoryPressureHandler::respondToMemoryPressure(Critical, Synchronous) { }
void MemoryPressureHandler::platformReleaseMemory(Critical) { }
std::optional<MemoryPressureHandler::ReliefLogger::MemoryUsage> MemoryPressureHandler::ReliefLogger::platformMemoryUsage() { return std::nullopt; }
#endif
} // namespace WebCore
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