Add malloc benchmarks.

Adding some benchmarks that keep a certain number of allocation
around. This benchmark should not be used as an absolute for determining
what is a good/bad native allocator. However, it should be used to make
sure that numbers are not completely changed between allocator versions.

Also update the malloc sql benchmark to match the same style as these
new benchmarks.

Bug: 129743239

Test: Ran these benchmarks.
Change-Id: I1995d98fd269b61d9c96efed6eff3ed278e24c97
Merged-In: I1995d98fd269b61d9c96efed6eff3ed278e24c97
(cherry picked from commit 7ec2c8a9b6f9a050d2ac9e0c35f0a631573f3de6)
diff --git a/benchmarks/malloc_benchmark.cpp b/benchmarks/malloc_benchmark.cpp
index 2fa1c87..ca54f11 100644
--- a/benchmarks/malloc_benchmark.cpp
+++ b/benchmarks/malloc_benchmark.cpp
@@ -102,22 +102,27 @@
 //       bionic/libc/malloc_debug/tools/gen_malloc.pl -i <THREAD_ID> g_sql_entries kMaxSqlAllocSlots < <ALLOC_FILE> > malloc_sql.h
 #include "malloc_sql.h"
 
-static void BM_malloc_sql_trace_decay_time_0(benchmark::State& state) {
+static void BM_malloc_sql_trace_default(benchmark::State& state) {
+  // The default is expected to be a zero decay time.
   mallopt(M_DECAY_TIME, 0);
-  for (auto _ : state) {
-    BenchmarkMalloc(g_sql_entries, sizeof(g_sql_entries) / sizeof(MallocEntry),
-                    kMaxSqlAllocSlots);
-  }
-}
-BIONIC_BENCHMARK(BM_malloc_sql_trace_decay_time_0);
 
-static void BM_malloc_sql_trace_decay_time_1(benchmark::State& state) {
-  mallopt(M_DECAY_TIME, 1);
   for (auto _ : state) {
     BenchmarkMalloc(g_sql_entries, sizeof(g_sql_entries) / sizeof(MallocEntry),
                     kMaxSqlAllocSlots);
   }
 }
-BIONIC_BENCHMARK(BM_malloc_sql_trace_decay_time_1);
+BIONIC_BENCHMARK(BM_malloc_sql_trace_default);
+
+static void BM_malloc_sql_trace_decay1(benchmark::State& state) {
+  mallopt(M_DECAY_TIME, 1);
+
+  for (auto _ : state) {
+    BenchmarkMalloc(g_sql_entries, sizeof(g_sql_entries) / sizeof(MallocEntry),
+                    kMaxSqlAllocSlots);
+  }
+
+  mallopt(M_DECAY_TIME, 0);
+}
+BIONIC_BENCHMARK(BM_malloc_sql_trace_decay1);
 
 #endif
diff --git a/benchmarks/stdlib_benchmark.cpp b/benchmarks/stdlib_benchmark.cpp
index 7330dc4..6afe7aa 100644
--- a/benchmarks/stdlib_benchmark.cpp
+++ b/benchmarks/stdlib_benchmark.cpp
@@ -17,30 +17,120 @@
 #include <err.h>
 #include <langinfo.h>
 #include <locale.h>
+#include <malloc.h>
 #include <stdlib.h>
 #include <unistd.h>
 
 #include <benchmark/benchmark.h>
 #include "util.h"
 
-static void BM_stdlib_malloc_free(benchmark::State& state) {
+#if defined(__BIONIC__)
+
+#else
+#endif
+
+static __always_inline void MakeAllocationResident(void* ptr, size_t nbytes, int pagesize) {
+  uint8_t* data = reinterpret_cast<uint8_t*>(ptr);
+  for (size_t i = 0; i < nbytes; i += pagesize) {
+    data[i] = 1;
+  }
+}
+
+static void MallocFree(benchmark::State& state) {
   const size_t nbytes = state.range(0);
   int pagesize = getpagesize();
 
-  void* ptr;
   for (auto _ : state) {
-    ptr = malloc(nbytes);
-    // Make the entire allocation resident.
-    uint8_t* data = reinterpret_cast<uint8_t*>(ptr);
-    for (size_t i = 0; i < nbytes; i += pagesize) {
-      data[i] = 1;
-    }
+    void* ptr;
+    benchmark::DoNotOptimize(ptr = malloc(nbytes));
+    MakeAllocationResident(ptr, nbytes, pagesize);
     free(ptr);
   }
 
   state.SetBytesProcessed(uint64_t(state.iterations()) * uint64_t(nbytes));
 }
-BIONIC_BENCHMARK_WITH_ARG(BM_stdlib_malloc_free, "AT_COMMON_SIZES");
+
+static void BM_stdlib_malloc_free_default(benchmark::State& state) {
+#if defined(__BIONIC__)
+  // The default is expected to be a zero decay time.
+  mallopt(M_DECAY_TIME, 0);
+#endif
+
+  MallocFree(state);
+}
+BIONIC_BENCHMARK_WITH_ARG(BM_stdlib_malloc_free_default, "AT_COMMON_SIZES");
+
+#if defined(__BIONIC__)
+static void BM_stdlib_malloc_free_decay1(benchmark::State& state) {
+  mallopt(M_DECAY_TIME, 1);
+
+  MallocFree(state);
+
+  mallopt(M_DECAY_TIME, 0);
+}
+BIONIC_BENCHMARK_WITH_ARG(BM_stdlib_malloc_free_decay1, "AT_COMMON_SIZES");
+#endif
+
+static void MallocMultiple(benchmark::State& state, size_t nbytes, size_t numAllocs) {
+  int pagesize = getpagesize();
+  void* ptrs[numAllocs];
+  for (auto _ : state) {
+    for (size_t i = 0; i < numAllocs; i++) {
+      benchmark::DoNotOptimize(ptrs[i] = reinterpret_cast<uint8_t*>(malloc(nbytes)));
+      MakeAllocationResident(ptrs[i], nbytes, pagesize);
+    }
+    state.PauseTiming(); // Stop timers while freeing pointers.
+    for (size_t i = 0; i < numAllocs; i++) {
+      free(ptrs[i]);
+    }
+    state.ResumeTiming();
+  }
+
+  state.SetBytesProcessed(uint64_t(state.iterations()) * uint64_t(nbytes) * numAllocs);
+}
+
+void BM_stdlib_malloc_forty_default(benchmark::State& state) {
+
+#if defined(__BIONIC__)
+  // The default is expected to be a zero decay time.
+  mallopt(M_DECAY_TIME, 0);
+#endif
+
+  MallocMultiple(state, state.range(0), 40);
+}
+BIONIC_BENCHMARK_WITH_ARG(BM_stdlib_malloc_forty_default, "AT_COMMON_SIZES");
+
+#if defined(__BIONIC__)
+void BM_stdlib_malloc_forty_decay1(benchmark::State& state) {
+  mallopt(M_DECAY_TIME, 1);
+
+  MallocMultiple(state, state.range(0), 40);
+
+  mallopt(M_DECAY_TIME, 0);
+}
+BIONIC_BENCHMARK_WITH_ARG(BM_stdlib_malloc_forty_decay1, "AT_COMMON_SIZES");
+#endif
+
+void BM_stdlib_malloc_multiple_8192_allocs_default(benchmark::State& state) {
+#if defined(__BIONIC__)
+  // The default is expected to be a zero decay time.
+  mallopt(M_DECAY_TIME, 0);
+#endif
+
+  MallocMultiple(state, 8192, state.range(0));
+}
+BIONIC_BENCHMARK_WITH_ARG(BM_stdlib_malloc_multiple_8192_allocs_default, "AT_SMALL_SIZES");
+
+#if defined(__BIONIC__)
+void BM_stdlib_malloc_multiple_8192_allocs_decay1(benchmark::State& state) {
+  mallopt(M_DECAY_TIME, 1);
+
+  MallocMultiple(state, 8192, state.range(0));
+
+  mallopt(M_DECAY_TIME, 0);
+}
+BIONIC_BENCHMARK_WITH_ARG(BM_stdlib_malloc_multiple_8192_allocs_decay1, "AT_SMALL_SIZES");
+#endif
 
 static void BM_stdlib_mbstowcs(benchmark::State& state) {
   const size_t buf_alignment = state.range(0);
@@ -167,3 +257,4 @@
   }
 }
 BIONIC_BENCHMARK(BM_stdlib_strtoull);
+