logwrapper: add a benchmark for android_fork_execvp_ext

Current results on an aosp_angler (32 bit) :

Benchmark                           Time           CPU Iterations
-----------------------------------------------------------------
BM_android_fork_execvp_ext   15019207 ns    1002131 ns        700

Test: android_fork_execvp_ext_benchmark

Change-Id: I3d4339ff5cbb9a641cbb14f0b55d2b5fc18cdfde

logwrapper/Android.bp

@@ -32,3 +32,22 @@ cc_binary {
         "-Werror",
     ],
 }
+
+// ========================================================
+// Benchmark
+// ========================================================
+cc_benchmark {
+    name: "android_fork_execvp_ext_benchmark",
+    srcs: [
+        "android_fork_execvp_ext_benchmark.cpp",
+    ],
+    shared_libs: [
+        "libbase",
+        "libcutils",
+        "liblog",
+        "liblogwrap",
+    ],
+    cflags: [
+        "-Werror",
+    ]
+}

logwrapper/android_fork_execvp_ext_benchmark.cpp

@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2017 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 "logwrap/logwrap.h"
+
+#include <android-base/logging.h>
+#include <benchmark/benchmark.h>
+
+static void BM_android_fork_execvp_ext(benchmark::State& state) {
+    const char* argv[] = {"/system/bin/echo", "hello", "world"};
+    const int argc = 3;
+    while (state.KeepRunning()) {
+        int rc = android_fork_execvp_ext(
+            argc, (char**)argv, NULL /* status */, false /* ignore_int_quit */, LOG_NONE,
+            false /* abbreviated */, NULL /* file_path */, NULL /* opts */, 0 /* opts_len */);
+        CHECK_EQ(0, rc);
+    }
+}
+BENCHMARK(BM_android_fork_execvp_ext);
+
+BENCHMARK_MAIN();