From d6cd6ba6d387d1d6e1c8cd8077ff6ae596fb7065 Mon Sep 17 00:00:00 2001
From: Fan Xu <fanxu@google.com>
Date: Thu, 15 Nov 2018 16:46:55 -0800
Subject: Add garbage collecion function to BufferHubService

Now BufferHubService will cleanup unused BufferClient automatically.

If the mClientList storing weak pointer, when user side's strong pointer
dies, the refcount will become 0 and the allocated memory in the service
will get freed.

Test: BufferHubBuffer_test (passed)
Bug: 119623209
Change-Id: I1390f878bf44afd7c1a5cccaeb34a9d13dab3db0
---
 services/bufferhub/BufferHubService.cpp                 | 2 +-
 services/bufferhub/include/bufferhub/BufferHubService.h | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/services/bufferhub/BufferHubService.cpp b/services/bufferhub/BufferHubService.cpp
index fc5ad1dbbf..1a38dd80b7 100644
--- a/services/bufferhub/BufferHubService.cpp
+++ b/services/bufferhub/BufferHubService.cpp
@@ -58,7 +58,7 @@ Return<void> BufferHubService::importBuffer(const hidl_handle& /*nativeHandle*/,
     return Void();
 }
 
-hidl_handle BufferHubService::registerToken(const BufferClient* client) {
+hidl_handle BufferHubService::registerToken(const wp<BufferClient>& client) {
     uint32_t token;
     std::lock_guard<std::mutex> lock(mTokenMapMutex);
     do {
diff --git a/services/bufferhub/include/bufferhub/BufferHubService.h b/services/bufferhub/include/bufferhub/BufferHubService.h
index 5441750e9a..e3f657fdd7 100644
--- a/services/bufferhub/include/bufferhub/BufferHubService.h
+++ b/services/bufferhub/include/bufferhub/BufferHubService.h
@@ -46,18 +46,18 @@ public:
 
     // Non-binder functions
     // Internal help function for IBufferClient::duplicate.
-    hidl_handle registerToken(const BufferClient* client);
+    hidl_handle registerToken(const wp<BufferClient>& client);
 
 private:
     // List of active BufferClient for bookkeeping.
     std::mutex mClientListMutex;
-    std::vector<sp<BufferClient>> mClientList GUARDED_BY(mClientListMutex);
+    std::vector<wp<BufferClient>> mClientList GUARDED_BY(mClientListMutex);
 
     // TODO(b/118180214): use a more secure implementation
     std::mt19937 mTokenEngine;
     // The mapping from token to the client creates it.
     std::mutex mTokenMapMutex;
-    std::map<uint32_t, const BufferClient*> mTokenMap GUARDED_BY(mTokenMapMutex);
+    std::map<uint32_t, const wp<BufferClient>> mTokenMap GUARDED_BY(mTokenMapMutex);
 };
 
 } // namespace implementation
-- 
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