Nfc: deal with the framework going away.

By calling close() when the framework client dies.

Bug: 35624326
Test: NFC HAL stays alive and works after com.android.nfc is killed
Change-Id: I91fcf6685783cd630a44d19b4cb99127a2c0e89b
(cherry picked from commit 85ca13052700f6356215225ebb8d35a2f3f09cc3)
diff --git a/nfc/1.0/default/Nfc.cpp b/nfc/1.0/default/Nfc.cpp
index 3bd5e41..c610406 100644
--- a/nfc/1.0/default/Nfc.cpp
+++ b/nfc/1.0/default/Nfc.cpp
@@ -14,12 +14,14 @@
 
 sp<INfcClientCallback> Nfc::mCallback = NULL;
 
-Nfc::Nfc(nfc_nci_device_t* device) : mDevice(device) {
+Nfc::Nfc(nfc_nci_device_t* device) : mDevice(device),
+    mDeathRecipient(new NfcDeathRecipient(this)) {
 }
 
 // Methods from ::android::hardware::nfc::V1_0::INfc follow.
 ::android::hardware::Return<NfcStatus> Nfc::open(const sp<INfcClientCallback>& clientCallback)  {
     mCallback = clientCallback;
+    mCallback->linkToDeath(mDeathRecipient, 0 /*cookie*/);
     int ret = mDevice->open(mDevice, eventCallback, dataCallback);
     return ret == 0 ? NfcStatus::OK : NfcStatus::FAILED;
 }
@@ -39,6 +41,7 @@
 }
 
 ::android::hardware::Return<NfcStatus> Nfc::close()  {
+    mCallback->unlinkToDeath(mDeathRecipient);
     return mDevice->close(mDevice) ? NfcStatus::FAILED : NfcStatus::OK;
 }
 
diff --git a/nfc/1.0/default/Nfc.h b/nfc/1.0/default/Nfc.h
index 13004a5..d8787fd 100644
--- a/nfc/1.0/default/Nfc.h
+++ b/nfc/1.0/default/Nfc.h
@@ -19,6 +19,16 @@
 using ::android::hardware::hidl_string;
 using ::android::sp;
 
+struct NfcDeathRecipient : hidl_death_recipient {
+    NfcDeathRecipient(const sp<INfc> nfc) : mNfc(nfc) {
+    }
+
+    virtual void serviceDied(uint64_t /*cookie*/, const wp<::android::hidl::base::V1_0::IBase>& /*who*/) {
+        mNfc->close();
+    }
+    sp<INfc> mNfc;
+};
+
 struct Nfc : public INfc {
   Nfc(nfc_nci_device_t* device);
   ::android::hardware::Return<NfcStatus> open(const sp<INfcClientCallback>& clientCallback)  override;
@@ -31,21 +41,28 @@
 
   static void eventCallback(uint8_t event, uint8_t status) {
       if (mCallback != nullptr) {
-          mCallback->sendEvent(
+          auto ret = mCallback->sendEvent(
                   (::android::hardware::nfc::V1_0::NfcEvent) event,
                   (::android::hardware::nfc::V1_0::NfcStatus) status);
+          if (!ret.isOk()) {
+              ALOGW("Failed to call back into NFC process.");
+          }
       }
   }
   static void dataCallback(uint16_t data_len, uint8_t* p_data) {
       hidl_vec<uint8_t> data;
       data.setToExternal(p_data, data_len);
       if (mCallback != nullptr) {
-          mCallback->sendData(data);
+          auto ret = mCallback->sendData(data);
+          if (!ret.isOk()) {
+              ALOGW("Failed to call back into NFC process.");
+          }
       }
   }
   private:
     static sp<INfcClientCallback> mCallback;
     const nfc_nci_device_t*       mDevice;
+    sp<NfcDeathRecipient>         mDeathRecipient;
 };
 
 extern "C" INfc* HIDL_FETCH_INfc(const char* name);