commit 154b0883f920d75161f1100ed054718392e166c6
author Brian Duddie <bduddie@google.com> Thu Jun 01 18:51:22 2017 -0700
committer Brian Duddie <bduddie@google.com> Mon Jun 05 14:16:22 2017 -0700
tree 8162c8b0b24e62c0add59c1eeecb055d67389c6c
parent 827e291043c3d48dbf49540e6a11d567a1b96154

contexthub: Handle service death

Register for notification of service death for callbacks registered with
the context hub HAL. Upon this notification, unregister the callback to
avoid crashing if an event occurs prior to the service coming back up.

Bug: 36202367
Test: adb shell stop, confirm death notification received via log;
  vts-tradefed run commandAndExit vts --module VtsHalContexthubV1_0Target
Change-Id: I3c25229806cb9f2a116007939c752841edbf0985

contexthub/1.0/default/Contexthub.cpp

diff --git a/contexthub/1.0/default/Contexthub.cpp b/contexthub/1.0/default/Contexthub.cpp
index 4a6b3f2..bf45900 100644
--- a/contexthub/1.0/default/Contexthub.cpp
+++ b/contexthub/1.0/default/Contexthub.cpp
@@ -38,6 +38,7 @@
 Contexthub::Contexthub()
         : mInitCheck(NO_INIT),
           mContextHubModule(nullptr),
+          mDeathRecipient(new DeathRecipient(this)),
           mIsTransactionPending(false) {
     const hw_module_t *module;
 
@@ -96,7 +97,7 @@
             c.stoppedPowerDrawMw = hubArray[i].stopped_power_draw_mw;
             c.sleepPowerDrawMw = hubArray[i].sleep_power_draw_mw;
 
-            info.callBack = nullptr;
+            info.callback = nullptr;
             info.osAppName = hubArray[i].os_app_name;
             mCachedHubInfo[hubArray[i].hub_id] = info;
 
@@ -110,6 +111,16 @@
     return Void();
 }
 
+Contexthub::DeathRecipient::DeathRecipient(sp<Contexthub> contexthub)
+        : mContexthub(contexthub) {}
+
+void Contexthub::DeathRecipient::serviceDied(
+        uint64_t cookie,
+        const wp<::android::hidl::base::V1_0::IBase>& /*who*/) {
+    uint32_t hubId = static_cast<uint32_t>(cookie);
+    mContexthub->handleServiceDeath(hubId);
+}
+
 bool Contexthub::isValidHubId(uint32_t hubId) {
     if (!mCachedHubInfo.count(hubId)) {
         ALOGW("Hub information not found for hubId %" PRIu32, hubId);
@@ -123,7 +134,7 @@
     if (!isValidHubId(hubId)) {
         return nullptr;
     } else {
-        return mCachedHubInfo[hubId].callBack;
+        return mCachedHubInfo[hubId].callback;
     }
 }
 
@@ -193,8 +204,22 @@
                                                      contextHubCb,
                                                      this) == 0) {
         // Initialized && valid hub && subscription successful
+        if (mCachedHubInfo[hubId].callback != nullptr) {
+            ALOGD("Modifying callback for hubId %" PRIu32, hubId);
+            mCachedHubInfo[hubId].callback->unlinkToDeath(mDeathRecipient);
+        }
+
+        mCachedHubInfo[hubId].callback = cb;
+        if (cb != nullptr) {
+            Return<bool> linkResult = cb->linkToDeath(mDeathRecipient, hubId);
+            bool linkSuccess = linkResult.isOk() ?
+                static_cast<bool>(linkResult) : false;
+            if (!linkSuccess) {
+                ALOGW("Couldn't link death recipient for hubId %" PRIu32,
+                      hubId);
+            }
+        }
         retVal = Result::OK;
-        mCachedHubInfo[hubId].callBack = cb;
     } else {
         // Initalized && valid hubId - but subscription unsuccessful
         // This is likely an internal error in the HAL implementation, but we
@@ -309,6 +334,16 @@
       return retVal;
 }
 
+void Contexthub::handleServiceDeath(uint32_t hubId) {
+    ALOGI("Callback/service died for hubId %" PRIu32, hubId);
+    int ret = mContextHubModule->subscribe_messages(hubId, nullptr, nullptr);
+    if (ret != 0) {
+        ALOGW("Failed to unregister callback from hubId %" PRIu32 ": %d",
+              hubId, ret);
+    }
+    mCachedHubInfo[hubId].callback.clear();
+}
+
 int Contexthub::contextHubCb(uint32_t hubId,
                              const struct hub_message_t *rxMsg,
                              void *cookie) {