bionic: change properties benchmarks to read a single property

The properties benchmarks were reading n properties from a property
area with n properties in it, which was making it hard to compare
the time between runs of different sizes.  Change the benchmark
to read a random property per iteration so the numbers between
runs are comparable.

Change-Id: Ib1648ce0948d9038fce76d209608427376cfb8da

1 files changed, 6 insertions, 6 deletions

diff --git a/tests/property_benchmark.cpp b/tests/property_benchmark.cpp
index dbd11ad..5acd06c 100644
--- a/tests/property_benchmark.cpp
+++ b/tests/property_benchmark.cpp
@@ -87,12 +87,12 @@ static void BM_property_get(int iters, int nprops)
     LocalPropertyTestState pa(nprops);
     char value[PROP_VALUE_MAX];
 
+    srandom(iters * nprops);
+
     StartBenchmarkTiming();
 
     for (int i = 0; i < iters; i++) {
-        for (int j = 0; j < nprops; j++) {
-            __system_property_get(pa.names[j], value);
-        }
+        __system_property_get(pa.names[random() % nprops], value);
     }
     StopBenchmarkTiming();
 }
@@ -104,12 +104,12 @@ static void BM_property_find(int iters, int nprops)
 
     LocalPropertyTestState pa(nprops);
 
+    srandom(iters * nprops);
+
     StartBenchmarkTiming();
 
     for (int i = 0; i < iters; i++) {
-        for (int j = 0; j < nprops; j++) {
-            __system_property_find(pa.names[j]);
-        }
+        __system_property_find(pa.names[random() % nprops]);
     }
     StopBenchmarkTiming();
 }