Add mallopt M_PURGE benchmark.

Update the native allocator documentation to include running of this
benchmark.

Move the malloc_benchmark.cpp to malloc_sql_benchmark.cpp and use
malloc_benchmark.cpp for benchmarking functions from malloc.h.

Bug: 137795072

Test: Ran new benchmark.
Change-Id: I76856de833032da324ad0bc0b6bd85a4ea8c253d

1 files changed, 129 insertions, 0 deletions

diff --git a/benchmarks/malloc_sql_benchmark.cpp b/benchmarks/malloc_sql_benchmark.cpp
new file mode 100644
index 000000000..383325ccb
--- /dev/null
+++ b/benchmarks/malloc_sql_benchmark.cpp
@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+#include <malloc.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <benchmark/benchmark.h>
+#include "util.h"
+
+#if defined(__BIONIC__)
+
+enum AllocEnum : uint8_t {
+  MALLOC = 0,
+  CALLOC,
+  MEMALIGN,
+  REALLOC,
+  FREE,
+};
+
+struct MallocEntry {
+  AllocEnum type;
+  size_t idx;
+  size_t size;
+  size_t arg2;
+};
+
+void BenchmarkMalloc(MallocEntry entries[], size_t total_entries, size_t max_allocs) {
+  void* ptrs[max_allocs];
+
+  for (size_t i = 0; i < total_entries; i++) {
+    switch (entries[i].type) {
+    case MALLOC:
+      ptrs[entries[i].idx] = malloc(entries[i].size);
+      // Touch at least one byte of the allocation to make sure that
+      // PSS for this allocation is counted.
+      reinterpret_cast<uint8_t*>(ptrs[entries[i].idx])[0] = 10;
+      break;
+    case CALLOC:
+      ptrs[entries[i].idx] = calloc(entries[i].arg2, entries[i].size);
+      // Touch at least one byte of the allocation to make sure that
+      // PSS for this allocation is counted.
+      reinterpret_cast<uint8_t*>(ptrs[entries[i].idx])[0] = 20;
+      break;
+    case MEMALIGN:
+      ptrs[entries[i].idx] = memalign(entries[i].arg2, entries[i].size);
+      // Touch at least one byte of the allocation to make sure that
+      // PSS for this allocation is counted.
+      reinterpret_cast<uint8_t*>(ptrs[entries[i].idx])[0] = 30;
+      break;
+    case REALLOC:
+      if (entries[i].arg2 == 0) {
+        ptrs[entries[i].idx] = realloc(nullptr, entries[i].size);
+      } else {
+        ptrs[entries[i].idx] = realloc(ptrs[entries[i].arg2 - 1], entries[i].size);
+      }
+      // Touch at least one byte of the allocation to make sure that
+      // PSS for this allocation is counted.
+      reinterpret_cast<uint8_t*>(ptrs[entries[i].idx])[0] = 40;
+      break;
+    case FREE:
+      free(ptrs[entries[i].idx]);
+      break;
+    }
+  }
+}
+
+// This codifies playing back a single threaded trace of the allocations
+// when running the SQLite BenchMark app.
+// Instructions for recreating:
+//   - Enable malloc debug
+//       setprop wrap.com.wtsang02.sqliteutil "LIBC_DEBUG_MALLOC_OPTIONS=record_allocs logwrapper"
+//   - Start the SQLite BenchMark app
+//   - Dump allocs using the signal to get rid of non sql allocs(kill -47 <SQLITE_PID>)
+//   - Run the benchmark.
+//   - Dump allocs using the signal again.
+//   - Find the thread that has the most allocs and run the helper script
+//       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_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_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