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/*
* Copyright (C) 2018 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include <sys/types.h>
#include <string>
#include <vector>
#include "meminfo.h"
namespace android {
namespace meminfo {
using VmaCallback = std::function<void(const Vma&)>;
class ProcMemInfo final {
// Per-process memory accounting
public:
// Reset the working set accounting of the process via /proc/<pid>/clear_refs
static bool ResetWorkingSet(pid_t pid);
ProcMemInfo(pid_t pid, bool get_wss = false, uint64_t pgflags = 0, uint64_t pgflags_mask = 0);
const std::vector<Vma>& Maps();
const MemUsage& Usage();
const MemUsage& Wss();
// Same as Maps() except, only valid for reading working set using CONFIG_IDLE_PAGE_TRACKING
// support in kernel. If the kernel support doesn't exist, the function will return an empty
// vector.
const std::vector<Vma>& MapsWithPageIdle();
// Same as Maps() except, do not read the usage stats for each map.
const std::vector<Vma>& MapsWithoutUsageStats();
// Collect all 'vma' or 'maps' from /proc/<pid>/smaps and store them in 'maps_'. Returns a
// constant reference to the vma vector after the collection is done.
//
// Each 'struct Vma' is *fully* populated by this method (unlike SmapsOrRollup).
const std::vector<Vma>& Smaps(const std::string& path = "");
// This method reads /proc/<pid>/smaps and calls the callback() for each
// vma or map that it finds. The map is converted to 'struct Vma' object which is then
// passed to the callback.
// Returns 'false' if the file is malformed.
bool ForEachVma(const VmaCallback& callback);
// Used to parse either of /proc/<pid>/{smaps, smaps_rollup} and record the process's
// Pss and Private memory usage in 'stats'. In particular, the method only populates the fields
// of the MemUsage structure that are intended to be used by Android's periodic Pss collection.
//
// The method populates the following statistics in order to be fast an efficient.
// Pss
// Rss
// Uss
// private_clean
// private_dirty
// SwapPss
// All other fields of MemUsage are zeroed.
bool SmapsOrRollup(MemUsage* stats) const;
// Used to parse either of /proc/<pid>/{smaps, smaps_rollup} and record the process's
// Pss.
// Returns 'true' on success and the value of Pss in the out parameter.
bool SmapsOrRollupPss(uint64_t* pss) const;
const std::vector<uint16_t>& SwapOffsets();
// Reads /proc/<pid>/pagemap for this process for each page within
// the 'vma' and stores that in 'pagemap'. It is assumed that the 'vma'
// is obtained by calling Maps() or 'ForEachVma' for the same object. No special checks
// are made to see if 'vma' is *valid*.
// Returns false if anything goes wrong, 'true' otherwise.
bool PageMap(const Vma& vma, std::vector<uint64_t>* pagemap);
~ProcMemInfo() = default;
private:
bool ReadMaps(bool get_wss, bool use_pageidle = false, bool get_usage_stats = true);
bool ReadVmaStats(int pagemap_fd, Vma& vma, bool get_wss, bool use_pageidle);
pid_t pid_;
bool get_wss_;
uint64_t pgflags_;
uint64_t pgflags_mask_;
std::vector<Vma> maps_;
MemUsage usage_;
std::vector<uint16_t> swap_offsets_;
};
// Makes callback for each 'vma' or 'map' found in file provided. The file is expected to be in the
// same format as /proc/<pid>/smaps. Returns 'false' if the file is malformed.
bool ForEachVmaFromFile(const std::string& path, const VmaCallback& callback);
// Returns if the kernel supports /proc/<pid>/smaps_rollup. Assumes that the
// calling process has access to the /proc/<pid>/smaps_rollup.
// Returns 'false' if the calling process has no permission to read the file if it exists
// of if the file doesn't exist.
bool IsSmapsRollupSupported(pid_t pid);
// Same as ProcMemInfo::SmapsOrRollup but reads the statistics directly
// from a file. The file MUST be in the same format as /proc/<pid>/smaps
// or /proc/<pid>/smaps_rollup
bool SmapsOrRollupFromFile(const std::string& path, MemUsage* stats);
// Same as ProcMemInfo::SmapsOrRollupPss but reads the statistics directly
// from a file and returns total Pss in kB. The file MUST be in the same format
// as /proc/<pid>/smaps or /proc/<pid>/smaps_rollup
bool SmapsOrRollupPssFromFile(const std::string& path, uint64_t* pss);
} // namespace meminfo
} // namespace android