tcp: Throw exception when trying to connect if not enough resource mem

Author: AndreasAakesson

src/net/tcp/connection.cpp

@@ -53,8 +53,9 @@ Connection::Connection(TCP& host, Socket local, Socket remote, ConnectCallback c
 
 Connection::~Connection()
 {
-  //printf("<Connection> Deleted %p %s  ACTIVE: %u\n", this,
+  //printf("<Connection> Deleted %p %s  ACTIVE: %zu\n", this,
   //        to_string().c_str(), host_.active_connections());
+
   rtx_clear();
 }
 

src/net/tcp/tcp.cpp

@@ -492,28 +492,43 @@ bool TCP::unbind(const Socket& socket)
   return false;
 }
 
-bool TCP::add_connection(tcp::Connection_ptr conn) {
+bool TCP::add_connection(tcp::Connection_ptr conn)
+{
+  const size_t alloc_thres = max_bufsize() * Read_request::buffer_limit;
   // Stat increment number of incoming connections
   (*incoming_connections_)++;
 
   debug("<TCP::add_connection> Connection added %s \n", conn->to_string().c_str());
-  conn->bufalloc = mempool_.get_resource();
+  auto resource = mempool_.get_resource();
 
   // Reject connection if we can't allocate memory
-  if (conn->bufalloc == nullptr
-      or conn->bufalloc->allocatable() < max_bufsize() * Read_request::buffer_limit){
+  if(UNLIKELY(resource == nullptr or resource->allocatable() < alloc_thres))
+  {
     conn->_on_cleanup_ = nullptr;
     conn->abort();
     return false;
   }
 
+  conn->bufalloc = std::move(resource);
+
+  //printf("New inc conn %s allocatable=%zu\n", conn->to_string().c_str(), conn->bufalloc->allocatable());
+
   Expects(conn->bufalloc != nullptr);
   conn->_on_cleanup({this, &TCP::close_connection});
   return connections_.emplace(conn->tuple(), conn).second;
 }
 
 Connection_ptr TCP::create_connection(Socket local, Socket remote, ConnectCallback cb)
 {
+  const size_t alloc_thres = max_bufsize() * Read_request::buffer_limit;
+
+  auto resource = mempool_.get_resource();
+  // Don't create connection if we can't allocate memory
+  if(UNLIKELY(resource == nullptr or resource->allocatable() < alloc_thres))
+  {
+    throw TCP_error{"Unable to create new connection: Not enough allocatable memory"};
+  }
+
   // Stat increment number of outgoing connections
   (*outgoing_connections_)++;
 
@@ -523,7 +538,10 @@ Connection_ptr TCP::create_connection(Socket local, Socket remote, ConnectCallba
       )
     ).first->second;
   conn->_on_cleanup({this, &TCP::close_connection});
-  conn->bufalloc = mempool_.get_resource();
+  conn->bufalloc = std::move(resource);
+
+  //printf("New out conn %s allocatable=%zu\n", conn->to_string().c_str(), conn->bufalloc->allocatable());
+
   Expects(conn->bufalloc != nullptr);
   return conn;
 }