Keeping sp<IBinder> around in ClientCache

binderDied is no longer called if all sp references are dropped in SF
process.  Keep an sp<IBinder> around so that we can get notified to
clean up the ClientCache/RenderEngine

Bug: b/144371238
Test: build, boot, manual (script to open and close Chrome
repeatedly, check RenderEngine image cache size in dumpsys), SurfaceFlinger_test,
libsurfaceflinger_unittest

Change-Id: Ib9374c02db59e09ca53280acc64419bda6827a4d

2 files changed, 9 insertions, 6 deletions

diff --git a/services/surfaceflinger/ClientCache.cpp b/services/surfaceflinger/ClientCache.cpp
index 16fe27c00a..a5be01c75c 100644
--- a/services/surfaceflinger/ClientCache.cpp
+++ b/services/surfaceflinger/ClientCache.cpp
@@ -42,7 +42,7 @@ bool ClientCache::getBuffer(const client_cache_t& cacheId,
         return false;
     }
 
-    auto& processBuffers = it->second;
+    auto& processBuffers = it->second.second;
 
     auto bufItr = processBuffers.find(id);
     if (bufItr == processBuffers.end()) {
@@ -86,12 +86,14 @@ bool ClientCache::add(const client_cache_t& cacheId, const sp<GraphicBuffer>& bu
             return false;
         }
         auto [itr, success] =
-                mBuffers.emplace(processToken, std::unordered_map<uint64_t, ClientCacheBuffer>());
+                mBuffers.emplace(processToken,
+                                 std::make_pair(token,
+                                                std::unordered_map<uint64_t, ClientCacheBuffer>()));
         LOG_ALWAYS_FATAL_IF(!success, "failed to insert new process into client cache");
         it = itr;
     }
 
-    auto& processBuffers = it->second;
+    auto& processBuffers = it->second.second;
 
     if (processBuffers.size() > BUFFER_CACHE_MAX_SIZE) {
         ALOGE("failed to cache buffer: cache is full");
@@ -120,7 +122,7 @@ void ClientCache::erase(const client_cache_t& cacheId) {
             }
         }
 
-        mBuffers[processToken].erase(id);
+        mBuffers[processToken].second.erase(id);
     }
 
     for (auto& recipient : pendingErase) {
@@ -180,7 +182,7 @@ void ClientCache::removeProcess(const wp<IBinder>& processToken) {
             return;
         }
 
-        for (auto& [id, clientCacheBuffer] : itr->second) {
+        for (auto& [id, clientCacheBuffer] : itr->second.second) {
             client_cache_t cacheId = {processToken, id};
             for (auto& recipient : clientCacheBuffer.recipients) {
                 sp<ErasedRecipient> erasedRecipient = recipient.promote();
diff --git a/services/surfaceflinger/ClientCache.h b/services/surfaceflinger/ClientCache.h
index aa6c80dfa7..d7af7c0e97 100644
--- a/services/surfaceflinger/ClientCache.h
+++ b/services/surfaceflinger/ClientCache.h
@@ -61,7 +61,8 @@ private:
         std::set<wp<ErasedRecipient>> recipients;
     };
     std::map<wp<IBinder> /*caching process*/,
-             std::unordered_map<uint64_t /*cache id*/, ClientCacheBuffer>>
+             std::pair<sp<IBinder> /*strong ref to caching process*/,
+                       std::unordered_map<uint64_t /*cache id*/, ClientCacheBuffer>>>
             mBuffers GUARDED_BY(mMutex);
 
     class CacheDeathRecipient : public IBinder::DeathRecipient {