#103: exa.ReadData not working correctly under Windows (#104)

RCA:
During the refactoring (#63),
the magic number = 1 for closing the socket for sending was
replaced with SD_RECEIVE, but it should have been replaced with SD_SEND.
The consequence was that the socket might have been closed
before the ok answered was sent to the database.

Fix:
Replace SD_RECEIVE with SD_SEND

Fixes #103

Author: tomuben

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: exasol
 Type: Package
 Title: R Interface & SDK for the EXASOL Database
-Version: 7.0.1
+Version: 7.0.2
 Date: 2021-10-07
 Author: Ian Formanek, Marcel Boldt, Mathias Golombek, Muhammet Orazov, Pieterjan Spoelders, Sebastian Baer, Szilard Barany, Thomas Ubensee, Torsten Kilias, Valerie Wiedemann, Viliam Simko
 Maintainer: Thomas Ubensee <ext.Thomas.Uebensee@exasol.com>

configure

@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.69 for exasol 7.0.1.
+# Generated by GNU Autoconf 2.69 for exasol 7.0.2.
 #
 #
 # Copyright (C) 1992-1996, 1998-2012 Free Software Foundation, Inc.
@@ -578,8 +578,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='exasol'
 PACKAGE_TARNAME='exasol'
-PACKAGE_VERSION='7.0.1'
-PACKAGE_STRING='exasol 7.0.1'
+PACKAGE_VERSION='7.0.2'
+PACKAGE_STRING='exasol 7.0.2'
 PACKAGE_BUGREPORT=''
 PACKAGE_URL=''
 
@@ -1210,7 +1210,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures exasol 7.0.1 to adapt to many kinds of systems.
+\`configure' configures exasol 7.0.2 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1272,7 +1272,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of exasol 7.0.1:";;
+     short | recursive ) echo "Configuration of exasol 7.0.2:";;
    esac
   cat <<\_ACEOF
 
@@ -1360,7 +1360,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-exasol configure 7.0.1
+exasol configure 7.0.2
 generated by GNU Autoconf 2.69
 
 Copyright (C) 2012 Free Software Foundation, Inc.
@@ -1538,7 +1538,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by exasol $as_me 7.0.1, which was
+It was created by exasol $as_me 7.0.2, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   $ $0 $@
@@ -4418,7 +4418,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by exasol $as_me 7.0.1, which was
+This file was extended by exasol $as_me 7.0.2, which was
 generated by GNU Autoconf 2.69.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -4471,7 +4471,7 @@ _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config="`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`"
 ac_cs_version="\\
-exasol config.status 7.0.1
+exasol config.status 7.0.2
 configured by $0, generated by GNU Autoconf 2.69,
   with options \\"\$ac_cs_config\\"
 

doc/changes/changelog.md

@@ -1,5 +1,6 @@
 # Changes
 
+* [7.0.2](changes_7.0.2.md)
 * [7.0.1](changes_7.0.1.md)
 * [7.0.0](changes_7.0.0.md)
 * [6.0.0](changes_6.0.0.md)

doc/changes/changes_7.0.2.md

@@ -0,0 +1,28 @@
+# r-exasol 7.0.2, released t.b.d.
+
+Code name: Fix socket error under Windows.
+
+## Summary 
+
+This release fixes a critical error under Windows which caused the 
+high speed data channel to abort the connection with an error.
+
+## Features / Enhancements
+n/a
+
+## Bug Fixes
+- #103: exa.ReadData not working correctly under Windows
+
+### Compile Dependency Updates
+
+#### Linux
+n/a
+
+#### Windows
+n/a
+
+### Runtime Dependency Updates
+n/a
+
+### Test Dependency Updates
+n/a

src/r_exasol/connection/socket/socket.h

@@ -13,9 +13,33 @@ namespace exa {
     class Socket {
     public:
         virtual ~Socket() = default;
+        /**
+         * Receive a buffer from the socket. The method blocks until the buffer is received.
+         * @param buf The pointer of the buffer to receive the data.
+         * @param len The size of the buffer.
+         * @return -1 if an error occurred. Otherwise the size of the buffer which was received.
+         */
         virtual ssize_t recv(void *buf, size_t len) = 0;
+        /**
+         * Send data to socket. The method is none-blocking.
+         * @param buf Pointer to buffer to send.
+         * @param len Length of the buffer to send.
+         * @return -1 if an error occurred. Otherwise the length of the buffer which was sent.
+         */
         virtual ssize_t send(const void *buf, size_t len) = 0;
+        /**
+         * Closes socket for sending.
+         * All ongoing send operations will be finished, but future send operations on the socket
+         * are not allowed.
+         * @see https://www.baeldung.com/cs/sockets-close-vs-shutdown#shutdown
+         */
         virtual void shutdownWr() = 0;
+        /**
+         * Closes socket for both sending/receiving.
+         * All ongoing send/receive operations will be finished, but future send/receive operations on the socket
+         * are not allowed.
+         * @see https://www.baeldung.com/cs/sockets-close-vs-shutdown#shutdown
+         */
         virtual void shutdownRdWr() = 0;
     };
 }

src/r_exasol/external/socket_api.h

@@ -13,11 +13,20 @@
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
 #include <winsock2.h>
+//SOCKET SHUT_RDWR
+//See https://docs.microsoft.com/en-us/windows/win32/api/winsock/nf-winsock-shutdown
+//Send: "If the how parameter is SD_SEND, subsequent calls to the send function are disallowed. For TCP sockets, a FIN will be sent after all data is sent and acknowledged by the receiver."
+//Receive: "If the how parameter is SD_RECEIVE, subsequent calls to the recv function on the socket will be disallowed. This has no effect on the lower protocol layers. For TCP sockets, if there is still data queued on the socket waiting to be received, or data arrives subsequently, the connection is reset, since the data cannot be delivered to the user. For UDP sockets, incoming datagrams are accepted and queued. In no case will an ICMP error packet be generated."
+//SD_BOTH corresponds to Linux SHUT_RDWR
 #ifndef SHUT_RDWR
 #define SHUT_RDWR SD_BOTH
 #endif
+//SOCKET SHUT_WR
+//See https://docs.microsoft.com/en-us/windows/win32/api/winsock/nf-winsock-shutdown
+//"If the how parameter is SD_SEND, subsequent calls to the send function are disallowed. For TCP sockets, a FIN will be sent after all data is sent and acknowledged by the receiver."
+//SD_SEND corresponds to Linux SHUT_WR
 #ifndef SHUT_WR
-#define SHUT_WR SD_RECEIVE
+#define SHUT_WR SD_SEND
 #endif
 
 #endif