Reland "RPC Binder: dropping all binders drops session"
This reverts commit 30a96fcc9ef87244469c93c0dea087008dad58fd.
Bug: 271830568
Fixes: 273486801 - also disabled clang-tidy check this is hitting
Test: binderRpcTest
Change-Id: I655cf2c2542b71aaab610cd9cbc5a7d53755178f
diff --git a/libs/binder/RpcState.h b/libs/binder/RpcState.h
index ac86585..0e23ea7 100644
--- a/libs/binder/RpcState.h
+++ b/libs/binder/RpcState.h
@@ -168,6 +168,7 @@
void clear();
private:
+ void clear(RpcMutexUniqueLock nodeLock);
void dumpLocked();
// Alternative to std::vector<uint8_t> that doesn't abort on allocation failure and caps
@@ -268,11 +269,20 @@
std::string toString() const;
};
- // checks if there is any reference left to a node and erases it. If erase
- // happens, and there is a strong reference to the binder kept by
- // binderNode, this returns that strong reference, so that it can be
- // dropped after any locks are removed.
- sp<IBinder> tryEraseNode(std::map<uint64_t, BinderNode>::iterator& it);
+ // Checks if there is any reference left to a node and erases it. If this
+ // is the last node, shuts down the session.
+ //
+ // Node lock is passed here for convenience, so that we can release it
+ // and terminate the session, but we could leave it up to the caller
+ // by returning a continuation if we needed to erase multiple specific
+ // nodes. It may be tempting to allow the client to keep on holding the
+ // lock and instead just return whether or not we should shutdown, but
+ // this introduces the posssibility that another thread calls
+ // getRootBinder and thinks it is valid, rather than immediately getting
+ // an error.
+ sp<IBinder> tryEraseNode(const sp<RpcSession>& session, RpcMutexUniqueLock nodeLock,
+ std::map<uint64_t, BinderNode>::iterator& it);
+
// true - success
// false - session shutdown, halt
[[nodiscard]] bool nodeProgressAsyncNumber(BinderNode* node);