Add Tracing for Binder Caching

Test: perfetto -c <perfetto config>
Bug: 333854840
Change-Id: Iffb1e00f94722f60c85305e0596ce58b0df5a6da
diff --git a/libs/binder/BackendUnifiedServiceManager.cpp b/libs/binder/BackendUnifiedServiceManager.cpp
index 52b485a..37aaaf3 100644
--- a/libs/binder/BackendUnifiedServiceManager.cpp
+++ b/libs/binder/BackendUnifiedServiceManager.cpp
@@ -114,11 +114,30 @@
     if (!kUseCache) {
         return binder::Status::ok();
     }
+    std::string traceStr;
+    if (atrace_is_tag_enabled(ATRACE_TAG_AIDL)) {
+        traceStr = "BinderCacheWithInvalidation::updateCache : " + serviceName;
+    }
+    binder::ScopedTrace aidlTrace(ATRACE_TAG_AIDL, traceStr.c_str());
+
     if (service.getTag() == os::Service::Tag::binder) {
         sp<IBinder> binder = service.get<os::Service::Tag::binder>();
-        if (binder && mCacheForGetService->isClientSideCachingEnabled(serviceName) &&
-            binder->isBinderAlive()) {
+        if (!binder) {
+            binder::ScopedTrace
+                    aidlTrace(ATRACE_TAG_AIDL,
+                              "BinderCacheWithInvalidation::updateCache failed: binder_null");
+        } else if (!binder->isBinderAlive()) {
+            binder::ScopedTrace aidlTrace(ATRACE_TAG_AIDL,
+                                          "BinderCacheWithInvalidation::updateCache failed: "
+                                          "isBinderAlive_false");
+        } else if (mCacheForGetService->isClientSideCachingEnabled(serviceName)) {
+            binder::ScopedTrace aidlTrace(ATRACE_TAG_AIDL,
+                                          "BinderCacheWithInvalidation::updateCache successful");
             return mCacheForGetService->setItem(serviceName, binder);
+        } else {
+            binder::ScopedTrace aidlTrace(ATRACE_TAG_AIDL,
+                                          "BinderCacheWithInvalidation::updateCache failed: "
+                                          "caching_not_enabled");
         }
     }
     return binder::Status::ok();