Add benchmarks for symbol reading.

Add a number of benchmarks to time how long it takes to look
up symbols.

Test: Ran benchmarks on device.
Change-Id: Iab7aab3f60c2c7056395beca3d36263420bcb5dc

libunwindstack/Android.bp

@@ -373,12 +373,26 @@ cc_benchmark {
 
     srcs: [
         "benchmarks/unwind_benchmarks.cpp",
+        "benchmarks/SymbolBenchmark.cpp",
+    ],
+
+    data: [
+        "benchmarks/files/*",
     ],
 
     shared_libs: [
         "libbase",
         "libunwindstack",
     ],
+
+    target: {
+        android: {
+            static_libs: [
+                "libmeminfo",
+                "libprocinfo",
+            ],
+        },
+    },
 }
 
 // Generates the elf data for use in the tests for .gnu_debugdata frames.

libunwindstack/benchmarks/SymbolBenchmark.cpp

@@ -0,0 +1,158 @@
+/*
+ * Copyright (C) 2020 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 <err.h>
+#include <inttypes.h>
+#include <malloc.h>
+#include <stdint.h>
+
+#include <string>
+#include <vector>
+
+#include <android-base/file.h>
+#include <android-base/strings.h>
+#include <benchmark/benchmark.h>
+
+#include <unwindstack/Elf.h>
+#include <unwindstack/Memory.h>
+
+#if defined(__BIONIC__)
+
+#include <meminfo/procmeminfo.h>
+#include <procinfo/process_map.h>
+
+static void Gather(uint64_t* rss_bytes) {
+  android::meminfo::ProcMemInfo proc_mem(getpid());
+  const std::vector<android::meminfo::Vma>& maps = proc_mem.MapsWithoutUsageStats();
+  for (auto& vma : maps) {
+    if (vma.name == "[anon:libc_malloc]" || android::base::StartsWith(vma.name, "[anon:scudo:") ||
+        android::base::StartsWith(vma.name, "[anon:GWP-ASan")) {
+      android::meminfo::Vma update_vma(vma);
+      if (!proc_mem.FillInVmaStats(update_vma)) {
+        err(1, "FillInVmaStats failed\n");
+      }
+      *rss_bytes += update_vma.usage.rss;
+    }
+  }
+}
+#endif
+
+static void BenchmarkSymbolLookup(benchmark::State& state, std::vector<uint64_t> offsets,
+                                  std::string elf_file, bool expect_found) {
+#if defined(__BIONIC__)
+  uint64_t rss_bytes = 0;
+#endif
+  uint64_t alloc_bytes = 0;
+  for (auto _ : state) {
+    state.PauseTiming();
+    unwindstack::Elf elf(unwindstack::Memory::CreateFileMemory(elf_file, 0).release());
+    if (!elf.Init() || !elf.valid()) {
+      errx(1, "Internal Error: Cannot open elf.");
+    }
+
+#if defined(__BIONIC__)
+    mallopt(M_PURGE, 0);
+    uint64_t rss_bytes_before = 0;
+    Gather(&rss_bytes_before);
+#endif
+    uint64_t alloc_bytes_before = mallinfo().uordblks;
+    state.ResumeTiming();
+
+    for (auto pc : offsets) {
+      std::string name;
+      uint64_t offset;
+      bool found = elf.GetFunctionName(pc, &name, &offset);
+      if (expect_found && !found) {
+        errx(1, "expected pc 0x%" PRIx64 " present, but not found.", pc);
+      } else if (!expect_found && found) {
+        errx(1, "expected pc 0x%" PRIx64 " not present, but found.", pc);
+      }
+    }
+
+    state.PauseTiming();
+#if defined(__BIONIC__)
+    mallopt(M_PURGE, 0);
+#endif
+    alloc_bytes += mallinfo().uordblks - alloc_bytes_before;
+#if defined(__BIONIC__)
+    Gather(&rss_bytes);
+    rss_bytes -= rss_bytes_before;
+#endif
+    state.ResumeTiming();
+  }
+
+#if defined(__BIONIC__)
+  state.counters["RSS_BYTES"] = rss_bytes / static_cast<double>(state.iterations());
+#endif
+  state.counters["ALLOCATED_BYTES"] = alloc_bytes / static_cast<double>(state.iterations());
+}
+
+static void BenchmarkSymbolLookup(benchmark::State& state, uint64_t pc, std::string elf_file,
+                                  bool expect_found) {
+  BenchmarkSymbolLookup(state, std::vector<uint64_t>{pc}, elf_file, expect_found);
+}
+
+std::string GetElfFile() {
+  return android::base::GetExecutableDirectory() + "/benchmarks/files/libart_arm.so";
+}
+
+std::string GetSortedElfFile() {
+  return android::base::GetExecutableDirectory() + "/benchmarks/files/boot_arm.oat";
+}
+
+void BM_symbol_not_present(benchmark::State& state) {
+  BenchmarkSymbolLookup(state, 0, GetElfFile(), false);
+}
+BENCHMARK(BM_symbol_not_present);
+
+void BM_symbol_find_single(benchmark::State& state) {
+  BenchmarkSymbolLookup(state, 0x22b2bc, GetElfFile(), true);
+}
+BENCHMARK(BM_symbol_find_single);
+
+void BM_symbol_find_single_many_times(benchmark::State& state) {
+  BenchmarkSymbolLookup(state, std::vector<uint64_t>(15, 0x22b2bc), GetElfFile(), true);
+}
+BENCHMARK(BM_symbol_find_single_many_times);
+
+void BM_symbol_find_multiple(benchmark::State& state) {
+  BenchmarkSymbolLookup(state,
+                        std::vector<uint64_t>{0x22b2bc, 0xd5d30, 0x1312e8, 0x13582e, 0x1389c8},
+                        GetElfFile(), true);
+}
+BENCHMARK(BM_symbol_find_multiple);
+
+void BM_symbol_not_present_from_sorted(benchmark::State& state) {
+  BenchmarkSymbolLookup(state, 0, GetSortedElfFile(), false);
+}
+BENCHMARK(BM_symbol_not_present_from_sorted);
+
+void BM_symbol_find_single_from_sorted(benchmark::State& state) {
+  BenchmarkSymbolLookup(state, 0x138638, GetSortedElfFile(), true);
+}
+BENCHMARK(BM_symbol_find_single_from_sorted);
+
+void BM_symbol_find_single_many_times_from_sorted(benchmark::State& state) {
+  BenchmarkSymbolLookup(state, std::vector<uint64_t>(15, 0x138638), GetSortedElfFile(), true);
+}
+BENCHMARK(BM_symbol_find_single_many_times_from_sorted);
+
+void BM_symbol_find_multiple_from_sorted(benchmark::State& state) {
+  BenchmarkSymbolLookup(state,
+                        std::vector<uint64_t>{0x138638, 0x84350, 0x14df18, 0x1f3a38, 0x1f3ca8},
+                        GetSortedElfFile(), true);
+}
+BENCHMARK(BM_symbol_find_multiple_from_sorted);