chromium/third_party/blink/renderer/controller/memory_usage_monitor_posix.cc

// Copyright 2019 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/351564777): Remove this and convert code to safer constructs.
#pragma allow_unsafe_buffers
#endif

#include "third_party/blink/renderer/controller/memory_usage_monitor_posix.h"

#include <fcntl.h>
#include <inttypes.h>
#include <unistd.h>

#include <utility>

#include "build/build_config.h"
#include "third_party/blink/public/platform/platform.h"

namespace blink {

namespace {

bool ReadFileContents(int fd, base::span<char> contents) { … }

static MemoryUsageMonitor* g_instance_for_testing = …;

MemoryUsageMonitorPosix& GetMemoryUsageMonitor() { … }

}  // namespace

// static
MemoryUsageMonitor& MemoryUsageMonitor::Instance() { … }

// static
void MemoryUsageMonitor::SetInstanceForTesting(MemoryUsageMonitor* instance) { … }

// Since the measurement is done every second in background, optimizations are
// in place to get just the metrics we need from the proc files. So, this
// calculation exists here instead of using the cross-process memory-infra code.
bool MemoryUsageMonitorPosix::CalculateProcessMemoryFootprint(
    int statm_fd,
    int status_fd,
    uint64_t* private_footprint,
    uint64_t* swap_footprint,
    uint64_t* vm_size,
    uint64_t* vm_hwm_size) { … }

void MemoryUsageMonitorPosix::GetProcessMemoryUsage(MemoryUsage& usage) { … }

#if BUILDFLAG(IS_ANDROID)
void MemoryUsageMonitorPosix::ResetFileDescriptors() {
  if (file_descriptors_reset_)
    return;
  file_descriptors_reset_ = true;
  // See https://goo.gl/KjWnZP For details about why we read these files from
  // sandboxed renderer. Keep these files open when detection is enabled.
  if (!statm_fd_.is_valid())
    statm_fd_.reset(open("/proc/self/statm", O_RDONLY));
  if (!status_fd_.is_valid())
    status_fd_.reset(open("/proc/self/status", O_RDONLY));
}
#endif

void MemoryUsageMonitorPosix::SetProcFiles(base::File statm_file,
                                           base::File status_file) { … }

#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)
// static
void MemoryUsageMonitorPosix::Bind(
    mojo::PendingReceiver<mojom::blink::MemoryUsageMonitorLinux> receiver) { … }
#endif

}  // namespace blink