On Sat, 14 Sep 2019 at 16:44, Ivan Zhakov <i...@visualsvn.com> wrote:
> Hi! > > The apr_socket_sendfile() has Windows specific flag > APR_SENDFILE_DISCONNECT_SOCKET. When this flag specified > instructs Winsock to disconnect socket and prepare it for > reuse after file send. > > There are several problems with this flag: > 1. The TCP socket may be subject to the TCP TIME_WAIT state. > That means apr_sock_sendfile() could occupy worker thread > for significant time (30 seconds) > > 2. When flag specified socket descriptor is removed from > apr_socket_t and will not be cleaned up. The caller > expected to maintain original socket descriptor and release > if APR_SENDFILE_DISCONNECT_SOCKET is used. > > As far I see Apache HTTP Server doesn't use APR_SENDFILE_DISCONNECT_SOCKET > flag. > > As far I understand proper way to reuse sockets is to use DisconnectEx() > [1]. > Application should use DisconnectEx() in overlapped I/O mode and wait > for it completion using completion port or thread pool. When overlapped I/O > is done the socket could be added to reuse list and later used for > AcceptEx() or > ConnectEx(). > > So I propose to remove APR_SENDFILE_DISCONNECT_SOCKET flag in APR 2.0 for > the > reasons above. Patch is attached. > > Any objections? > > [1] > https://docs.microsoft.com/en-gb/windows/win32/api/mswsock/nc-mswsock-lpfn_disconnectex > > Committed tweaked patch in r1867226. -- Ivan Zhakov
