From 7c298f5d14e9ef47b812983fbb8a8f446b536fb5 Mon Sep 17 00:00:00 2001 From: Martijn Otto Date: Wed, 7 Nov 2018 09:24:50 +0100 Subject: [PATCH] No longer use a list for registering self references in the abstract tcp server Updated assert message Use a local variable that won't destruct at the end of the if-branch Updated comment --- contrib/epee/include/net/abstract_tcp_server2.h | 3 ++- contrib/epee/include/net/abstract_tcp_server2.inl | 13 ++++++++----- 2 files changed, 10 insertions(+), 6 deletions(-) diff --git a/contrib/epee/include/net/abstract_tcp_server2.h b/contrib/epee/include/net/abstract_tcp_server2.h index 3f726a352..df2b9d1b2 100644 --- a/contrib/epee/include/net/abstract_tcp_server2.h +++ b/contrib/epee/include/net/abstract_tcp_server2.h @@ -155,7 +155,8 @@ namespace net_utils //this should be the last one, because it could be wait on destructor, while other activities possible on other threads t_protocol_handler m_protocol_handler; //typename t_protocol_handler::config_type m_dummy_config; - std::list > > m_self_refs; // add_ref/release support + size_t m_reference_count = 0; // reference count managed through add_ref/release support + boost::shared_ptr > m_self_ref; // the reference to hold critical_section m_self_refs_lock; critical_section m_chunking_lock; // held while we add small chunks of the big do_send() to small do_send_chunk() critical_section m_shutdown_lock; // held while shutting down diff --git a/contrib/epee/include/net/abstract_tcp_server2.inl b/contrib/epee/include/net/abstract_tcp_server2.inl index 9b03941ee..a74eb1f26 100644 --- a/contrib/epee/include/net/abstract_tcp_server2.inl +++ b/contrib/epee/include/net/abstract_tcp_server2.inl @@ -230,7 +230,8 @@ PRAGMA_WARNING_DISABLE_VS(4355) //_dbg3("[sock " << socket_.native_handle() << "] add_ref 2, m_peer_number=" << mI->m_peer_number); if(m_was_shutdown) return false; - m_self_refs.push_back(self); + ++m_reference_count; + m_self_ref = std::move(self); return true; CATCH_ENTRY_L0("connection::add_ref()", false); } @@ -242,10 +243,12 @@ PRAGMA_WARNING_DISABLE_VS(4355) boost::shared_ptr > back_connection_copy; LOG_TRACE_CC(context, "[sock " << socket_.native_handle() << "] release"); CRITICAL_REGION_BEGIN(m_self_refs_lock); - CHECK_AND_ASSERT_MES(m_self_refs.size(), false, "[sock " << socket_.native_handle() << "] m_self_refs empty at connection::release() call"); - //erasing from container without additional copy can cause start deleting object, including m_self_refs - back_connection_copy = m_self_refs.back(); - m_self_refs.pop_back(); + CHECK_AND_ASSERT_MES(m_reference_count, false, "[sock " << socket_.native_handle() << "] m_reference_count already at 0 at connection::release() call"); + // is this the last reference? + if (--m_reference_count == 0) { + // move the held reference to a local variable, keeping the object alive until the function terminates + std::swap(back_connection_copy, m_self_ref); + } CRITICAL_REGION_END(); return true; CATCH_ENTRY_L0("connection::release()", false);