commit 02530ec09450f050d0de3807407f432fe7b040b7
author Yifan Hong <elsk@google.com> Thu Jun 10 13:38:38 2021 -0700
committer Yifan Hong <elsk@google.com> Mon Jun 14 20:47:56 2021 -0700
tree 9de2432960ca249e53fce64b9d2b6481374e7df8
parent 936fc19aa0ca565dc0903c577658676ad76575b7

Add keepAliveBinder argument to setRpcClientDebug.

When the given binder object dies, the corresponding
RpcServer is also shut down.

This CL does not make use of the argument other than
null checks. See follow-up CL for implementation.

Test: binderLibTest
Bug: 182914638
Change-Id: Id787e70f885b165db703e7bb6fa01e6bec271fe6

libs/binder/Binder.cpp

diff --git a/libs/binder/Binder.cpp b/libs/binder/Binder.cpp
index 194be21..19a22a5 100644
--- a/libs/binder/Binder.cpp
+++ b/libs/binder/Binder.cpp
@@ -150,7 +150,8 @@
     return OK;
 }
 
-status_t IBinder::setRpcClientDebug(android::base::unique_fd socketFd) {
+status_t IBinder::setRpcClientDebug(android::base::unique_fd socketFd,
+                                    const sp<IBinder>& keepAliveBinder) {
     if constexpr (!kEnableRpcDevServers) {
         ALOGW("setRpcClientDebug disallowed because RPC is not enabled");
         return INVALID_OPERATION;
@@ -158,7 +159,7 @@
 
     BBinder* local = this->localBinder();
     if (local != nullptr) {
-        return local->BBinder::setRpcClientDebug(std::move(socketFd));
+        return local->BBinder::setRpcClientDebug(std::move(socketFd), keepAliveBinder);
     }
 
     BpBinder* proxy = this->remoteBinder();
@@ -173,6 +174,7 @@
         status = data.writeFileDescriptor(socketFd.release(), true /* own */);
         if (status != OK) return status;
     }
+    if (status = data.writeStrongBinder(keepAliveBinder); status != OK) return status;
     return transact(SET_RPC_CLIENT_TRANSACTION, data, &reply);
 }
 
@@ -453,11 +455,14 @@
     if (hasSocketFd) {
         if (status = data.readUniqueFileDescriptor(&clientFd); status != OK) return status;
     }
+    sp<IBinder> keepAliveBinder;
+    if (status = data.readNullableStrongBinder(&keepAliveBinder); status != OK) return status;
 
-    return setRpcClientDebug(std::move(clientFd));
+    return setRpcClientDebug(std::move(clientFd), keepAliveBinder);
 }
 
-status_t BBinder::setRpcClientDebug(android::base::unique_fd socketFd) {
+status_t BBinder::setRpcClientDebug(android::base::unique_fd socketFd,
+                                    const sp<IBinder>& keepAliveBinder) {
     if constexpr (!kEnableRpcDevServers) {
         ALOGW("%s: disallowed because RPC is not enabled", __PRETTY_FUNCTION__);
         return INVALID_OPERATION;
@@ -471,6 +476,11 @@
         return BAD_VALUE;
     }
 
+    if (keepAliveBinder == nullptr) {
+        ALOGE("%s: No keepAliveBinder provided.", __PRETTY_FUNCTION__);
+        return UNEXPECTED_NULL;
+    }
+
     size_t binderThreadPoolMaxCount = ProcessState::self()->getThreadPoolMaxThreadCount();
     if (binderThreadPoolMaxCount <= 1) {
         ALOGE("%s: ProcessState thread pool max count is %zu. RPC is disabled for this service "