libbinder : Adding new type TransportFd

Adding a new struct TransportFd which will contain unique_fd and
polling state of file descriptor. This will be useful in detecting
if all the descriptors are being polled. unique_fd and borrowed_fd
are replaced in these changes.

Test: m
Test: m libbinder binderRpcTest && atest binderRpcTest
Test: trusty/vendor/google/aosp/scripts/build.py  --test
      "boot-test:com.android.trusty.binder.test" qemu-generic-arm64-test-debug
Bug: 218518615
Change-Id: Id108806b98184582e5d93186b3b1884017c441ea
diff --git a/libs/binder/tests/binderRpcTest.cpp b/libs/binder/tests/binderRpcTest.cpp
index 4c037b7..cfdfdf8 100644
--- a/libs/binder/tests/binderRpcTest.cpp
+++ b/libs/binder/tests/binderRpcTest.cpp
@@ -1773,7 +1773,7 @@
                 }
             }
             mFd = rpcServer->releaseServer();
-            if (!mFd.ok()) return AssertionFailure() << "releaseServer returns invalid fd";
+            if (!mFd.fd.ok()) return AssertionFailure() << "releaseServer returns invalid fd";
             mCtx = newFactory(rpcSecurity, mCertVerifier, std::move(auth))->newServerCtx();
             if (mCtx == nullptr) return AssertionFailure() << "newServerCtx";
             mSetup = true;
@@ -1794,7 +1794,7 @@
             std::vector<std::thread> threads;
             while (OK == mFdTrigger->triggerablePoll(mFd, POLLIN)) {
                 base::unique_fd acceptedFd(
-                        TEMP_FAILURE_RETRY(accept4(mFd.get(), nullptr, nullptr /*length*/,
+                        TEMP_FAILURE_RETRY(accept4(mFd.fd.get(), nullptr, nullptr /*length*/,
                                                    SOCK_CLOEXEC | SOCK_NONBLOCK)));
                 threads.emplace_back(&Server::handleOne, this, std::move(acceptedFd));
             }
@@ -1803,7 +1803,8 @@
         }
         void handleOne(android::base::unique_fd acceptedFd) {
             ASSERT_TRUE(acceptedFd.ok());
-            auto serverTransport = mCtx->newTransport(std::move(acceptedFd), mFdTrigger.get());
+            TransportFd transportFd(std::move(acceptedFd));
+            auto serverTransport = mCtx->newTransport(std::move(transportFd), mFdTrigger.get());
             if (serverTransport == nullptr) return; // handshake failed
             ASSERT_TRUE(mPostConnect(serverTransport.get(), mFdTrigger.get()));
         }
@@ -1822,7 +1823,7 @@
         std::unique_ptr<std::thread> mThread;
         ConnectToServer mConnectToServer;
         std::unique_ptr<FdTrigger> mFdTrigger = FdTrigger::make();
-        base::unique_fd mFd;
+        TransportFd mFd;
         std::unique_ptr<RpcTransportCtx> mCtx;
         std::shared_ptr<RpcCertificateVerifierSimple> mCertVerifier =
                 std::make_shared<RpcCertificateVerifierSimple>();
@@ -1869,7 +1870,7 @@
         // connect() and do handshake
         bool setUpTransport() {
             mFd = mConnectToServer();
-            if (!mFd.ok()) return AssertionFailure() << "Cannot connect to server";
+            if (!mFd.fd.ok()) return AssertionFailure() << "Cannot connect to server";
             mClientTransport = mCtx->newTransport(std::move(mFd), mFdTrigger.get());
             return mClientTransport != nullptr;
         }
@@ -1898,9 +1899,11 @@
             ASSERT_EQ(readOk, readMessage());
         }
 
+        bool isTransportWaiting() { return mClientTransport->isWaiting(); }
+
     private:
         ConnectToServer mConnectToServer;
-        base::unique_fd mFd;
+        TransportFd mFd;
         std::unique_ptr<FdTrigger> mFdTrigger = FdTrigger::make();
         std::unique_ptr<RpcTransportCtx> mCtx;
         std::shared_ptr<RpcCertificateVerifierSimple> mCertVerifier =
@@ -2147,6 +2150,56 @@
     ASSERT_FALSE(client.readMessage(msg2));
 }
 
+TEST_P(RpcTransportTest, CheckWaitingForRead) {
+    std::mutex readMutex;
+    std::condition_variable readCv;
+    bool shouldContinueReading = false;
+    // Server will write data on transport once its started
+    auto serverPostConnect = [&](RpcTransport* serverTransport, FdTrigger* fdTrigger) {
+        std::string message(RpcTransportTestUtils::kMessage);
+        iovec messageIov{message.data(), message.size()};
+        auto status = serverTransport->interruptableWriteFully(fdTrigger, &messageIov, 1,
+                                                               std::nullopt, nullptr);
+        if (status != OK) return AssertionFailure() << statusToString(status);
+
+        {
+            std::unique_lock<std::mutex> lock(readMutex);
+            shouldContinueReading = true;
+            lock.unlock();
+            readCv.notify_all();
+        }
+        return AssertionSuccess();
+    };
+
+    // Setup Server and client
+    auto server = std::make_unique<Server>();
+    ASSERT_TRUE(server->setUp(GetParam()));
+
+    Client client(server->getConnectToServerFn());
+    ASSERT_TRUE(client.setUp(GetParam()));
+
+    ASSERT_EQ(OK, trust(&client, server));
+    ASSERT_EQ(OK, trust(server, &client));
+    server->setPostConnect(serverPostConnect);
+
+    server->start();
+    ASSERT_TRUE(client.setUpTransport());
+    {
+        // Wait till server writes data
+        std::unique_lock<std::mutex> lock(readMutex);
+        ASSERT_TRUE(readCv.wait_for(lock, 3s, [&] { return shouldContinueReading; }));
+    }
+
+    // Since there is no read polling here, we will get polling count 0
+    ASSERT_FALSE(client.isTransportWaiting());
+    ASSERT_TRUE(client.readMessage(RpcTransportTestUtils::kMessage));
+    // Thread should increment polling count, read and decrement polling count
+    // Again, polling count should be zero here
+    ASSERT_FALSE(client.isTransportWaiting());
+
+    server->shutdown();
+}
+
 INSTANTIATE_TEST_CASE_P(BinderRpc, RpcTransportTest,
                         ::testing::ValuesIn(RpcTransportTest::getRpcTranportTestParams()),
                         RpcTransportTest::PrintParamInfo);