Add a global elf cache.
Bug: 65682279
Test: Ran new unit tests.
Change-Id: I19c64614b2b11a27f58204d4cc34913c02e04c36
diff --git a/libunwindstack/Android.bp b/libunwindstack/Android.bp
index 8dae956..28d7e64 100644
--- a/libunwindstack/Android.bp
+++ b/libunwindstack/Android.bp
@@ -124,6 +124,7 @@
"tests/DwarfOpTest.cpp",
"tests/DwarfSectionTest.cpp",
"tests/DwarfSectionImplTest.cpp",
+ "tests/ElfCacheTest.cpp",
"tests/ElfFake.cpp",
"tests/ElfInterfaceArmTest.cpp",
"tests/ElfInterfaceTest.cpp",
diff --git a/libunwindstack/Elf.cpp b/libunwindstack/Elf.cpp
index f120da2..dbf772e 100644
--- a/libunwindstack/Elf.cpp
+++ b/libunwindstack/Elf.cpp
@@ -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 @@
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
diff --git a/libunwindstack/MapInfo.cpp b/libunwindstack/MapInfo.cpp
index 89fe038..0c15335 100644
--- a/libunwindstack/MapInfo.cpp
+++ b/libunwindstack/MapInfo.cpp
@@ -109,16 +109,46 @@
// 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) {
diff --git a/libunwindstack/include/unwindstack/Elf.h b/libunwindstack/include/unwindstack/Elf.h
index e562d6d..a874709 100644
--- a/libunwindstack/include/unwindstack/Elf.h
+++ b/libunwindstack/include/unwindstack/Elf.h
@@ -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 @@
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 @@
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
diff --git a/libunwindstack/include/unwindstack/MapInfo.h b/libunwindstack/include/unwindstack/MapInfo.h
index 22e48f7..a57fe68 100644
--- a/libunwindstack/include/unwindstack/MapInfo.h
+++ b/libunwindstack/include/unwindstack/MapInfo.h
@@ -20,6 +20,7 @@
#include <stdint.h>
#include <atomic>
+#include <memory>
#include <mutex>
#include <string>
@@ -40,14 +41,14 @@
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,
diff --git a/libunwindstack/tests/ElfCacheTest.cpp b/libunwindstack/tests/ElfCacheTest.cpp
new file mode 100644
index 0000000..0086c9e
--- /dev/null
+++ b/libunwindstack/tests/ElfCacheTest.cpp
@@ -0,0 +1,201 @@
+/*
+ * 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.
+ */
+
+#include <elf.h>
+#include <unistd.h>
+
+#include <android-base/file.h>
+#include <android-base/test_utils.h>
+
+#include <gtest/gtest.h>
+
+#include <unwindstack/Elf.h>
+#include <unwindstack/MapInfo.h>
+
+#include "ElfTestUtils.h"
+#include "MemoryFake.h"
+
+namespace unwindstack {
+
+class ElfCacheTest : public ::testing::Test {
+ protected:
+ static void SetUpTestCase() { memory_.reset(new MemoryFake); }
+
+ void SetUp() override { Elf::SetCachingEnabled(true); }
+
+ void TearDown() override { Elf::SetCachingEnabled(false); }
+
+ void WriteElfFile(uint64_t offset, TemporaryFile* tf, uint32_t type) {
+ ASSERT_TRUE(type == EM_ARM || type == EM_386 || type == EM_X86_64);
+ size_t ehdr_size;
+ Elf32_Ehdr ehdr32;
+ Elf64_Ehdr ehdr64;
+ void* ptr;
+ if (type == EM_ARM || type == EM_386) {
+ ehdr_size = sizeof(ehdr32);
+ ptr = &ehdr32;
+ TestInitEhdr(&ehdr32, ELFCLASS32, type);
+ } else {
+ ehdr_size = sizeof(ehdr64);
+ ptr = &ehdr64;
+ TestInitEhdr(&ehdr64, ELFCLASS64, type);
+ }
+
+ ASSERT_EQ(offset, static_cast<uint64_t>(lseek(tf->fd, offset, SEEK_SET)));
+ ASSERT_TRUE(android::base::WriteFully(tf->fd, ptr, ehdr_size));
+ }
+
+ void VerifyWithinSameMap(bool cache_enabled);
+ void VerifySameMap(bool cache_enabled);
+
+ static std::shared_ptr<Memory> memory_;
+};
+
+std::shared_ptr<Memory> ElfCacheTest::memory_;
+
+void ElfCacheTest::VerifySameMap(bool cache_enabled) {
+ if (!cache_enabled) {
+ Elf::SetCachingEnabled(false);
+ }
+
+ TemporaryFile tf;
+ ASSERT_TRUE(tf.fd != -1);
+ WriteElfFile(0, &tf, EM_ARM);
+ close(tf.fd);
+
+ uint64_t start = 0x1000;
+ uint64_t end = 0x20000;
+ MapInfo info1(start, end, 0, 0x5, tf.path);
+ MapInfo info2(start, end, 0, 0x5, tf.path);
+
+ Elf* elf1 = info1.GetElf(memory_, true);
+ ASSERT_TRUE(elf1->valid());
+ Elf* elf2 = info2.GetElf(memory_, true);
+ ASSERT_TRUE(elf2->valid());
+
+ if (cache_enabled) {
+ EXPECT_EQ(elf1, elf2);
+ } else {
+ EXPECT_NE(elf1, elf2);
+ }
+}
+
+TEST_F(ElfCacheTest, no_caching) {
+ VerifySameMap(false);
+}
+
+TEST_F(ElfCacheTest, caching_invalid_elf) {
+ VerifySameMap(true);
+}
+
+void ElfCacheTest::VerifyWithinSameMap(bool cache_enabled) {
+ if (!cache_enabled) {
+ Elf::SetCachingEnabled(false);
+ }
+
+ TemporaryFile tf;
+ ASSERT_TRUE(tf.fd != -1);
+ WriteElfFile(0, &tf, EM_ARM);
+ WriteElfFile(0x100, &tf, EM_386);
+ WriteElfFile(0x200, &tf, EM_X86_64);
+ lseek(tf.fd, 0x500, SEEK_SET);
+ uint8_t value = 0;
+ write(tf.fd, &value, 1);
+ close(tf.fd);
+
+ uint64_t start = 0x1000;
+ uint64_t end = 0x20000;
+ // Will have an elf at offset 0 in file.
+ MapInfo info0_1(start, end, 0, 0x5, tf.path);
+ MapInfo info0_2(start, end, 0, 0x5, tf.path);
+ // Will have an elf at offset 0x100 in file.
+ MapInfo info100_1(start, end, 0x100, 0x5, tf.path);
+ MapInfo info100_2(start, end, 0x100, 0x5, tf.path);
+ // Will have an elf at offset 0x200 in file.
+ MapInfo info200_1(start, end, 0x200, 0x5, tf.path);
+ MapInfo info200_2(start, end, 0x200, 0x5, tf.path);
+ // Will have an elf at offset 0 in file.
+ MapInfo info300_1(start, end, 0x300, 0x5, tf.path);
+ MapInfo info300_2(start, end, 0x300, 0x5, tf.path);
+
+ Elf* elf0_1 = info0_1.GetElf(memory_, true);
+ ASSERT_TRUE(elf0_1->valid());
+ EXPECT_EQ(ARCH_ARM, elf0_1->arch());
+ Elf* elf0_2 = info0_2.GetElf(memory_, true);
+ ASSERT_TRUE(elf0_2->valid());
+ EXPECT_EQ(ARCH_ARM, elf0_2->arch());
+ EXPECT_EQ(0U, info0_1.elf_offset);
+ EXPECT_EQ(0U, info0_2.elf_offset);
+ if (cache_enabled) {
+ EXPECT_EQ(elf0_1, elf0_2);
+ } else {
+ EXPECT_NE(elf0_1, elf0_2);
+ }
+
+ Elf* elf100_1 = info100_1.GetElf(memory_, true);
+ ASSERT_TRUE(elf100_1->valid());
+ EXPECT_EQ(ARCH_X86, elf100_1->arch());
+ Elf* elf100_2 = info100_2.GetElf(memory_, true);
+ ASSERT_TRUE(elf100_2->valid());
+ EXPECT_EQ(ARCH_X86, elf100_2->arch());
+ EXPECT_EQ(0U, info100_1.elf_offset);
+ EXPECT_EQ(0U, info100_2.elf_offset);
+ if (cache_enabled) {
+ EXPECT_EQ(elf100_1, elf100_2);
+ } else {
+ EXPECT_NE(elf100_1, elf100_2);
+ }
+
+ Elf* elf200_1 = info200_1.GetElf(memory_, true);
+ ASSERT_TRUE(elf200_1->valid());
+ EXPECT_EQ(ARCH_X86_64, elf200_1->arch());
+ Elf* elf200_2 = info200_2.GetElf(memory_, true);
+ ASSERT_TRUE(elf200_2->valid());
+ EXPECT_EQ(ARCH_X86_64, elf200_2->arch());
+ EXPECT_EQ(0U, info200_1.elf_offset);
+ EXPECT_EQ(0U, info200_2.elf_offset);
+ if (cache_enabled) {
+ EXPECT_EQ(elf200_1, elf200_2);
+ } else {
+ EXPECT_NE(elf200_1, elf200_2);
+ }
+
+ Elf* elf300_1 = info300_1.GetElf(memory_, true);
+ ASSERT_TRUE(elf300_1->valid());
+ EXPECT_EQ(ARCH_ARM, elf300_1->arch());
+ Elf* elf300_2 = info300_2.GetElf(memory_, true);
+ ASSERT_TRUE(elf300_2->valid());
+ EXPECT_EQ(ARCH_ARM, elf300_2->arch());
+ EXPECT_EQ(0x300U, info300_1.elf_offset);
+ EXPECT_EQ(0x300U, info300_2.elf_offset);
+ if (cache_enabled) {
+ EXPECT_EQ(elf300_1, elf300_2);
+ EXPECT_EQ(elf0_1, elf300_1);
+ } else {
+ EXPECT_NE(elf300_1, elf300_2);
+ EXPECT_NE(elf0_1, elf300_1);
+ }
+}
+
+TEST_F(ElfCacheTest, no_caching_valid_elf_offset_non_zero) {
+ VerifyWithinSameMap(false);
+}
+
+TEST_F(ElfCacheTest, caching_valid_elf_offset_non_zero) {
+ VerifyWithinSameMap(true);
+}
+
+} // namespace unwindstack
diff --git a/libunwindstack/tests/JitDebugTest.cpp b/libunwindstack/tests/JitDebugTest.cpp
index 1a50989..37628f8 100644
--- a/libunwindstack/tests/JitDebugTest.cpp
+++ b/libunwindstack/tests/JitDebugTest.cpp
@@ -62,7 +62,7 @@
ElfInterfaceFake* interface = new ElfInterfaceFake(elf_memories_.back());
elf->FakeSetInterface(interface);
interface->FakeSetGlobalVariable("__jit_debug_descriptor", 0x800);
- map_info->elf = elf;
+ map_info->elf.reset(elf);
map_info = maps_->Get(5);
ASSERT_TRUE(map_info != nullptr);
@@ -72,7 +72,7 @@
interface = new ElfInterfaceFake(elf_memories_.back());
elf->FakeSetInterface(interface);
interface->FakeSetGlobalVariable("__jit_debug_descriptor", 0x800);
- map_info->elf = elf;
+ map_info->elf.reset(elf);
map_info = maps_->Get(6);
ASSERT_TRUE(map_info != nullptr);
@@ -82,7 +82,7 @@
interface = new ElfInterfaceFake(elf_memories_.back());
elf->FakeSetInterface(interface);
interface->FakeSetGlobalVariable("__jit_debug_descriptor", 0x800);
- map_info->elf = elf;
+ map_info->elf.reset(elf);
}
template <typename EhdrType, typename ShdrType>
diff --git a/libunwindstack/tests/MapInfoGetElfTest.cpp b/libunwindstack/tests/MapInfoGetElfTest.cpp
index 948597b..f599503 100644
--- a/libunwindstack/tests/MapInfoGetElfTest.cpp
+++ b/libunwindstack/tests/MapInfoGetElfTest.cpp
@@ -180,16 +180,14 @@
ASSERT_TRUE(elf != nullptr);
ASSERT_FALSE(elf->valid());
- delete info.elf;
- info.elf = nullptr;
+ info.elf.reset();
info.end = 0xfff;
elf = info.GetElf(process_memory_, false);
ASSERT_TRUE(elf != nullptr);
ASSERT_FALSE(elf->valid());
// Make sure this test is valid.
- delete info.elf;
- info.elf = nullptr;
+ info.elf.reset();
info.end = 0x2000;
elf = info.GetElf(process_memory_, false);
ASSERT_TRUE(elf != nullptr);
@@ -328,8 +326,7 @@
ASSERT_TRUE(elf != nullptr);
ASSERT_FALSE(elf->valid());
- delete info.elf;
- info.elf = nullptr;
+ info.elf.reset();
info.flags = PROT_READ;
elf = info.GetElf(process_memory_, false);
ASSERT_TRUE(elf->valid());
@@ -352,15 +349,13 @@
ASSERT_FALSE(elf->valid());
// Set the name to nothing to verify that it still fails.
- delete info.elf;
- info.elf = nullptr;
+ info.elf.reset();
info.name = "";
elf = info.GetElf(process_memory_, false);
ASSERT_FALSE(elf->valid());
// Change the flags and verify the elf is valid now.
- delete info.elf;
- info.elf = nullptr;
+ info.elf.reset();
info.flags = PROT_READ;
elf = info.GetElf(process_memory_, false);
ASSERT_TRUE(elf->valid());
@@ -403,7 +398,7 @@
}
// Now verify that all of the elf files are exactly the same and valid.
- Elf* elf = info.elf;
+ Elf* elf = info.elf.get();
ASSERT_TRUE(elf != nullptr);
EXPECT_TRUE(elf->valid());
for (size_t i = 0; i < kNumConcurrentThreads; i++) {
diff --git a/libunwindstack/tests/MapInfoGetLoadBiasTest.cpp b/libunwindstack/tests/MapInfoGetLoadBiasTest.cpp
index 631036b..7e64a8a 100644
--- a/libunwindstack/tests/MapInfoGetLoadBiasTest.cpp
+++ b/libunwindstack/tests/MapInfoGetLoadBiasTest.cpp
@@ -69,7 +69,7 @@
}
TEST_F(MapInfoGetLoadBiasTest, load_bias_cached_from_elf) {
- map_info_->elf = elf_container_.release();
+ map_info_->elf.reset(elf_container_.release());
elf_->FakeSetLoadBias(0);
EXPECT_EQ(0U, map_info_->GetLoadBias(process_memory_));
@@ -79,7 +79,7 @@
}
TEST_F(MapInfoGetLoadBiasTest, elf_exists) {
- map_info_->elf = elf_container_.release();
+ map_info_->elf.reset(elf_container_.release());
elf_->FakeSetLoadBias(0);
EXPECT_EQ(0U, map_info_->GetLoadBias(process_memory_));
@@ -122,7 +122,7 @@
}
TEST_F(MapInfoGetLoadBiasTest, multiple_thread_elf_exists) {
- map_info_->elf = elf_container_.release();
+ map_info_->elf.reset(elf_container_.release());
elf_->FakeSetLoadBias(0x1000);
MultipleThreadTest(0x1000);
diff --git a/libunwindstack/tests/RegsTest.cpp b/libunwindstack/tests/RegsTest.cpp
index 15d5458..7c06373 100644
--- a/libunwindstack/tests/RegsTest.cpp
+++ b/libunwindstack/tests/RegsTest.cpp
@@ -184,7 +184,7 @@
RegsMips64 regs_mips64;
MapInfo map_info(0x1000, 0x2000);
Elf* invalid_elf = new Elf(new MemoryFake);
- map_info.elf = invalid_elf;
+ map_info.elf.reset(invalid_elf);
regs_arm.set_pc(0x1500);
EXPECT_EQ(0x500U, invalid_elf->GetRelPc(regs_arm.pc(), &map_info));
diff --git a/libunwindstack/tests/UnwinderTest.cpp b/libunwindstack/tests/UnwinderTest.cpp
index bf2c1d8..45cf907 100644
--- a/libunwindstack/tests/UnwinderTest.cpp
+++ b/libunwindstack/tests/UnwinderTest.cpp
@@ -60,7 +60,7 @@
maps_.FakeClear();
MapInfo* info = new MapInfo(0x1000, 0x8000, 0, PROT_READ | PROT_WRITE, "/system/fake/libc.so");
ElfFake* elf = new ElfFake(new MemoryFake);
- info->elf = elf;
+ info->elf.reset(elf);
elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
maps_.FakeAddMapInfo(info);
@@ -73,25 +73,25 @@
info = new MapInfo(0x20000, 0x22000, 0, PROT_READ | PROT_WRITE, "/system/fake/libunwind.so");
elf = new ElfFake(new MemoryFake);
- info->elf = elf;
+ info->elf.reset(elf);
elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
maps_.FakeAddMapInfo(info);
info = new MapInfo(0x23000, 0x24000, 0, PROT_READ | PROT_WRITE, "/fake/libanother.so");
elf = new ElfFake(new MemoryFake);
- info->elf = elf;
+ info->elf.reset(elf);
elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
maps_.FakeAddMapInfo(info);
info = new MapInfo(0x33000, 0x34000, 0, PROT_READ | PROT_WRITE, "/fake/compressed.so");
elf = new ElfFake(new MemoryFake);
- info->elf = elf;
+ info->elf.reset(elf);
elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
maps_.FakeAddMapInfo(info);
info = new MapInfo(0x43000, 0x44000, 0x1d000, PROT_READ | PROT_WRITE, "/fake/fake.apk");
elf = new ElfFake(new MemoryFake);
- info->elf = elf;
+ info->elf.reset(elf);
elf->FakeSetInterface(new ElfInterfaceFake(nullptr));
maps_.FakeAddMapInfo(info);