binderThroughputTest: skip benchmark loop for servers

Skip the entire benchmarking loop if this is a server worker instead of
asking the same fixed question on every single iteration.

Change-Id: I66d1578132099ea1cb4a3b5a10a830bb11b579a2
Test: Ran a benchmark on cuttlefish, and it did not get stuck
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>

Author: Carlos Llamas

libs/binder/tests/binderThroughputTest.cpp

@@ -223,29 +223,31 @@ void worker_fx(int num,
     p.signal();
     p.wait();
 
-    // Run the benchmark if client
     ProcResults results(iterations);
-
     chrono::time_point<chrono::high_resolution_clock> start, end;
-    for (int i = 0; (!cs_pair || num >= server_count) && i < iterations; i++) {
-        Parcel data, reply;
-        int target = cs_pair ? num % server_count : rand() % workers.size();
-        int sz = payload_size;
-
-        while (sz >= sizeof(uint32_t)) {
-            data.writeInt32(0);
-            sz -= sizeof(uint32_t);
-        }
-        start = chrono::high_resolution_clock::now();
-        status_t ret = workers[target]->transact(BINDER_NOP, data, &reply);
-        end = chrono::high_resolution_clock::now();
 
-        uint64_t cur_time = uint64_t(chrono::duration_cast<chrono::nanoseconds>(end - start).count());
-        results.add_time(cur_time);
+    // Skip the benchmark if server of a cs_pair.
+    if (!(cs_pair && num < server_count)) {
+        for (int i = 0; i < iterations; i++) {
+            Parcel data, reply;
+            int target = cs_pair ? num % server_count : rand() % workers.size();
+            int sz = payload_size;
+
+            while (sz >= sizeof(uint32_t)) {
+                data.writeInt32(0);
+                sz -= sizeof(uint32_t);
+            }
+            start = chrono::high_resolution_clock::now();
+            status_t ret = workers[target]->transact(BINDER_NOP, data, &reply);
+            end = chrono::high_resolution_clock::now();
+
+            uint64_t cur_time = uint64_t(chrono::duration_cast<chrono::nanoseconds>(end - start).count());
+            results.add_time(cur_time);
 
-        if (ret != NO_ERROR) {
-           cout << "thread " << num << " failed " << ret << "i : " << i << endl;
-           exit(EXIT_FAILURE);
+            if (ret != NO_ERROR) {
+               cout << "thread " << num << " failed " << ret << "i : " << i << endl;
+               exit(EXIT_FAILURE);
+            }
         }
     }