Fix publishing RPC Server on the same address/port after a short time

Bug: 274786956
Test: atest libsdvrpc_test_cpp

Change-Id: I58b0b99b5e3ab8c9659eed0eba9ff689000b84ac
diff --git a/libs/binder/RpcServer.cpp b/libs/binder/RpcServer.cpp
index 9282856..1635e2a 100644
--- a/libs/binder/RpcServer.cpp
+++ b/libs/binder/RpcServer.cpp
@@ -161,6 +161,12 @@
     mConnectionFilter = std::move(filter);
 }
 
+void RpcServer::setServerSocketModifier(std::function<void(base::borrowed_fd)>&& modifier) {
+    RpcMutexLockGuard _l(mLock);
+    LOG_ALWAYS_FATAL_IF(mServer.fd != -1, "Already started");
+    mServerSocketModifier = std::move(modifier);
+}
+
 sp<IBinder> RpcServer::getRootObject() {
     RpcMutexLockGuard _l(mLock);
     bool hasWeak = mRootObjectWeak.unsafe_get();
@@ -335,6 +341,8 @@
         mJoinThread.reset();
     }
 
+    mServer = RpcTransportFd();
+
     LOG_RPC_DETAIL("Finished waiting on shutdown.");
 
     mShutdownTrigger = nullptr;
@@ -556,6 +564,14 @@
         ALOGE("Could not create socket at %s: %s", addr.toString().c_str(), strerror(savedErrno));
         return -savedErrno;
     }
+
+    {
+        RpcMutexLockGuard _l(mLock);
+        if (mServerSocketModifier != nullptr) {
+            mServerSocketModifier(socket_fd);
+        }
+    }
+
     if (0 != TEMP_FAILURE_RETRY(bind(socket_fd.get(), addr.addr(), addr.addrSize()))) {
         int savedErrno = errno;
         ALOGE("Could not bind socket at %s: %s", addr.toString().c_str(), strerror(savedErrno));