Add various benchmarks.

These are based on ones from system/extras/tests/bionic/.

Change-Id: I7b1ae15a2ca5d1031a6a511d97b88125c1770047

benchmarks/semaphore_benchmark.cpp

@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2014 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 "benchmark.h"
+
+#include <semaphore.h>
+
+static void BM_semaphore_sem_getvalue(int iters) {
+  StopBenchmarkTiming();
+  sem_t semaphore;
+  sem_init(&semaphore, 1, 1);
+  StartBenchmarkTiming();
+
+  for (int i = 0; i < iters; ++i) {
+    int dummy;
+    sem_getvalue(&semaphore, &dummy);
+  }
+
+  StopBenchmarkTiming();
+}
+BENCHMARK(BM_semaphore_sem_getvalue);
+
+static void BM_semaphore_sem_wait_sem_post(int iters) {
+  StopBenchmarkTiming();
+  sem_t semaphore;
+  sem_init(&semaphore, 1, 1);
+  StartBenchmarkTiming();
+
+  for (int i = 0; i < iters; ++i) {
+    sem_wait(&semaphore);
+    sem_post(&semaphore);
+  }
+
+  StopBenchmarkTiming();
+}
+BENCHMARK(BM_semaphore_sem_wait_sem_post);