commit d88278d266242eb64aa0b548bc3575a2444d4118
author Steven Moreland <smoreland@google.com> Fri Jun 24 22:23:56 2022 +0000
committer Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> Fri Jun 24 22:23:56 2022 +0000
tree b301b070fdb9428474601fe6ee9417cc675a5d69
parent af1e289f744ca003847287c5ac14a314bcd7ef18
parent 28a7564a9eaea06ab589512a92d8beb944cb05c5

Merge "libbinder: fix hanging wait in RpcSession" am: 28a7564a9e

Original change: https://android-review.googlesource.com/c/platform/frameworks/native/+/2133631

Change-Id: I822d0dde98883fd7ab0f8ff43e83d98c0b15c2ab
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

libs/binder/RpcSession.cpp

diff --git a/libs/binder/RpcSession.cpp b/libs/binder/RpcSession.cpp
index 8edc78f..7ba08ed 100644
--- a/libs/binder/RpcSession.cpp
+++ b/libs/binder/RpcSession.cpp
@@ -699,10 +699,7 @@
                 mRpcBinderState->sendConnectionInit(connection, sp<RpcSession>::fromExisting(this));
     }
 
-    {
-        std::lock_guard<std::mutex> _l(mMutex);
-        connection->exclusiveTid = std::nullopt;
-    }
+    clearConnectionTid(connection);
 
     return status;
 }
@@ -773,6 +770,15 @@
     return false;
 }
 
+void RpcSession::clearConnectionTid(const sp<RpcConnection>& connection) {
+    std::unique_lock<std::mutex> _l(mMutex);
+    connection->exclusiveTid = std::nullopt;
+    if (mConnections.mWaitingThreads > 0) {
+        _l.unlock();
+        mAvailableConnectionCv.notify_one();
+    }
+}
+
 std::vector<uint8_t> RpcSession::getCertificate(RpcCertificateFormat format) {
     return mCtx->getCertificate(format);
 }
@@ -902,12 +908,7 @@
     // is using this fd, and it retains the right to it. So, we don't give up
     // exclusive ownership, and no thread is freed.
     if (!mReentrant && mConnection != nullptr) {
-        std::unique_lock<std::mutex> _l(mSession->mMutex);
-        mConnection->exclusiveTid = std::nullopt;
-        if (mSession->mConnections.mWaitingThreads > 0) {
-            _l.unlock();
-            mSession->mAvailableConnectionCv.notify_one();
-        }
+        mSession->clearConnectionTid(mConnection);
     }
 }
 

libs/binder/include/binder/RpcSession.h

diff --git a/libs/binder/include/binder/RpcSession.h b/libs/binder/include/binder/RpcSession.h
index e76b140..7d5d481 100644
--- a/libs/binder/include/binder/RpcSession.h
+++ b/libs/binder/include/binder/RpcSession.h
@@ -264,6 +264,7 @@
     sp<RpcConnection> assignIncomingConnectionToThisThread(
             std::unique_ptr<RpcTransport> rpcTransport);
     [[nodiscard]] bool removeIncomingConnection(const sp<RpcConnection>& connection);
+    void clearConnectionTid(const sp<RpcConnection>& connection);
 
     [[nodiscard]] status_t initShutdownTrigger();