platform_bionic/linker/linker_utils.h
Jiyong Park 341b61e694 Don't resolve already resolved paths when parsing ld.config.txt
When parsing ld.config.txt, paths in *.search.paths properties are
resolved using resolved_paths(). This is causing a number of newfstatat
system calls during a process start-up and is contributing about 3.6%
of the entire linker initialization time.

Optimize the overhead by not resolving already resolved paths; resolved
paths are cached.

Bug: 132348336
Test: strace -C -e newfstatat ls shows the number of the syscalls is
reduced from 131 to 99
Test: simpleperf record --call-graph fp -f 10000000 -o /data/perf.data ls
simpleperf report -g -i /data/perf.data
shows percentage of get_paths() from 2.9% to 2.5%

Change-Id: I79823255a89f6e2a63b80c74e6768850276ab536
2019-05-17 10:09:13 +09:00

61 lines
2.7 KiB
C++

/*
* Copyright (C) 2015 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * 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 THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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 THE
* COPYRIGHT OWNER 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.
*/
#pragma once
#include <string>
#include <vector>
extern const char* const kZipFileSeparator;
void format_string(std::string* str, const std::vector<std::pair<std::string, std::string>>& params);
bool file_is_in_dir(const std::string& file, const std::string& dir);
bool file_is_under_dir(const std::string& file, const std::string& dir);
bool normalize_path(const char* path, std::string* normalized_path);
bool parse_zip_path(const char* input_path, std::string* zip_path, std::string* entry_path);
// For every path element this function checks of it exists, and is a directory,
// and normalizes it:
// 1. For regular path it converts it to realpath()
// 2. For path in a zip file it uses realpath on the zipfile
// normalizes entry name by calling normalize_path function.
void resolve_paths(std::vector<std::string>& paths,
std::vector<std::string>* resolved_paths);
// Resolve a single path. Return empty string when the path is invalid or can't
// be resolved.
std::string resolve_path(const std::string& path);
void split_path(const char* path, const char* delimiters, std::vector<std::string>* paths);
std::string dirname(const char* path);
off64_t page_start(off64_t offset);
size_t page_offset(off64_t offset);
bool safe_add(off64_t* out, off64_t a, size_t b);
bool is_first_stage_init();