libbinder_ndk: stress test for retrieving binders

The logic is a bit complicated.

Fixes: 192321823
Test: fails every time w/o fix, works with fix
Change-Id: I6b4bb126a9fe1fa6d2b39a05805b3a14f53f1a7b
diff --git a/libs/binder/ndk/tests/libbinder_ndk_unit_test.cpp b/libs/binder/ndk/tests/libbinder_ndk_unit_test.cpp
index 1c43948..5ad390e 100644
--- a/libs/binder/ndk/tests/libbinder_ndk_unit_test.cpp
+++ b/libs/binder/ndk/tests/libbinder_ndk_unit_test.cpp
@@ -39,6 +39,7 @@
 #include <condition_variable>
 #include <iostream>
 #include <mutex>
+#include <thread>
 #include "android/binder_ibinder.h"
 
 using namespace android;
@@ -250,6 +251,27 @@
     EXPECT_EQ(2, out);
 }
 
+TEST(NdkBinder, GetTestServiceStressTest) {
+    // libbinder has some complicated logic to make sure only one instance of
+    // ABpBinder is associated with each binder.
+
+    constexpr size_t kNumThreads = 10;
+    constexpr size_t kNumCalls = 1000;
+    std::vector<std::thread> threads;
+
+    for (size_t i = 0; i < kNumThreads; i++) {
+        threads.push_back(std::thread([&]() {
+            for (size_t j = 0; j < kNumCalls; j++) {
+                auto binder =
+                        ndk::SpAIBinder(AServiceManager_checkService(IFoo::kSomeInstanceName));
+                EXPECT_EQ(STATUS_OK, AIBinder_ping(binder.get()));
+            }
+        }));
+    }
+
+    for (auto& thread : threads) thread.join();
+}
+
 void defaultInstanceCounter(const char* instance, void* context) {
     if (strcmp(instance, "default") == 0) {
         ++*(size_t*)(context);