Merge "Add a global elf cache." (bb4d172f) · Commits · e / os / android_system_core

libunwindstack/Android.bp

+1 −0

Original line number	Diff line number	Diff line
		@@ -124,6 +124,7 @@ cc_test {
		"tests/DwarfOpTest.cpp",
		"tests/DwarfSectionTest.cpp",
		"tests/DwarfSectionImplTest.cpp",
		"tests/ElfCacheTest.cpp",
		"tests/ElfFake.cpp",
		"tests/ElfInterfaceArmTest.cpp",
		"tests/ElfInterfaceTest.cpp",

+42 −0

Original line number	Diff line number	Diff line
		@@ -35,6 +35,10 @@

		namespace unwindstack {

		bool Elf::cache_enabled_;
		std::unordered_map<std::string, std::shared_ptr<Elf>>* Elf::cache_;
		std::mutex* Elf::cache_lock_;

		bool Elf::Init(bool init_gnu_debugdata) {
		load_bias_ = 0;
		if (!memory_) {
		@@ -301,4 +305,42 @@ uint64_t Elf::GetLoadBias(Memory* memory) {
		return 0;
		}

		void Elf::SetCachingEnabled(bool enable) {
		if (!cache_enabled_ && enable) {
		cache_enabled_ = true;
		cache_ = new std::unordered_map<std::string, std::shared_ptr<Elf>>;
		cache_lock_ = new std::mutex;
		} else if (cache_enabled_ && !enable) {
		cache_enabled_ = false;
		delete cache_;
		delete cache_lock_;
		}
		}

		void Elf::CacheLock() {
		cache_lock_->lock();
		}

		void Elf::CacheUnlock() {
		cache_lock_->unlock();
		}

		void Elf::CacheAdd(MapInfo* info) {
		if (info->offset == 0) {
		(*cache_)[info->name] = info->elf;
		} else {
		std::string name(info->name + ':' + std::to_string(info->offset));
		(*cache_)[name] = info->elf;
		}
		}

		bool Elf::CacheGet(const std::string& name, std::shared_ptr<Elf>* elf) {
		auto entry = cache_->find(name);
		if (entry != cache_->end()) {
		*elf = entry->second;
		return true;
		}
		return false;
		}

		} // namespace unwindstack

+35 −5

Original line number	Diff line number	Diff line
		@@ -109,16 +109,46 @@ Elf* MapInfo::GetElf(const std::shared_ptr<Memory>& process_memory, bool init_gn
		// Make sure no other thread is trying to add the elf to this map.
		std::lock_guard<std::mutex> guard(mutex_);

		if (elf) {
		return elf;
		if (elf.get() != nullptr) {
		return elf.get();
		}

		elf = new Elf(CreateMemory(process_memory));
		elf->Init(init_gnu_debugdata);
		bool locked = false;
		if (Elf::CachingEnabled() && !name.empty()) {
		Elf::CacheLock();
		locked = true;
		if (offset != 0) {
		std::string hash(name + ':' + std::to_string(offset));
		if (Elf::CacheGet(hash, &elf)) {
		Elf::CacheUnlock();
		return elf.get();
		}
		} else if (Elf::CacheGet(name, &elf)) {
		Elf::CacheUnlock();
		return elf.get();
		}
		}

		Memory* memory = CreateMemory(process_memory);
		if (locked && offset != 0 && elf_offset != 0) {
		// In this case, the whole file is the elf, need to see if the elf
		// data was cached.
		if (Elf::CacheGet(name, &elf)) {
		delete memory;
		Elf::CacheUnlock();
		return elf.get();
		}
		}
		elf.reset(new Elf(memory));
		// If the init fails, keep the elf around as an invalid object so we
		// don't try to reinit the object.
		return elf;
		elf->Init(init_gnu_debugdata);

		if (locked) {
		Elf::CacheAdd(this);
		Elf::CacheUnlock();
		}
		return elf.get();
		}

		uint64_t MapInfo::GetLoadBias(const std::shared_ptr<Memory>& process_memory) {

+13 −0

Original line number	Diff line number	Diff line
		@@ -22,6 +22,7 @@
		#include <memory>
		#include <mutex>
		#include <string>
		#include <unordered_map>

		#include <unwindstack/ElfInterface.h>
		#include <unwindstack/Memory.h>
		@@ -96,6 +97,14 @@ class Elf {

		static uint64_t GetLoadBias(Memory* memory);

		static void SetCachingEnabled(bool enable);
		static bool CachingEnabled() { return cache_enabled_; }

		static void CacheLock();
		static void CacheUnlock();
		static void CacheAdd(MapInfo* info);
		static bool CacheGet(const std::string& name, std::shared_ptr<Elf>* elf);

		protected:
		bool valid_ = false;
		uint64_t load_bias_ = 0;
		@@ -109,6 +118,10 @@ class Elf {

		std::unique_ptr<Memory> gnu_debugdata_memory_;
		std::unique_ptr<ElfInterface> gnu_debugdata_interface_;

		static bool cache_enabled_;
		static std::unordered_map<std::string, std::shared_ptr<Elf>>* cache_;
		static std::mutex* cache_lock_;
		};

		} // namespace unwindstack

+3 −2

Original line number	Diff line number	Diff line
		@@ -20,6 +20,7 @@
		#include <stdint.h>

		#include <atomic>
		#include <memory>
		#include <mutex>
		#include <string>

		@@ -40,14 +41,14 @@ struct MapInfo {
		flags(flags),
		name(name),
		load_bias(static_cast<uint64_t>(-1)) {}
		~MapInfo() { delete elf; }
		~MapInfo() = default;

		uint64_t start = 0;
		uint64_t end = 0;
		uint64_t offset = 0;
		uint16_t flags = 0;
		std::string name;
		Elf* elf = nullptr;
		std::shared_ptr<Elf> elf;
		// This value is only non-zero if the offset is non-zero but there is
		// no elf signature found at that offset. This indicates that the
		// entire file is represented by the Memory object returned by CreateMemory,