[zeromq-dev] (Fwd) [crossroads-dev] [PATCH] Correct handling of connect() errors in tcp, ipc_connecter_t

[Martin Lucina]

Hi,

FYI, the patch below is for an old bug, also affects ZeroMQ 3.1.0 and
2.1.11 (based on the last released versions I have local copies of, I can't
seem to access GH from here).

-mato

----- Forwarded message from Martin Lucina <martin at lucina.net> -----

Date: Thu,  3 May 2012 13:08:49 +0200
From: Martin Lucina <martin at lucina.net>
To: crossroads-dev at groups.crossroads.io
Cc: Martin Lucina <martin at lucina.net>
Subject: [crossroads-dev] [PATCH] Correct handling of connect() errors in tcp,
	ipc_connecter_t

EAGAIN was being used as a translation value for EINPROGRESS, thus
shadowing a real EAGAIN return value from the OS.  This caused later
assertions of "Invalid argument" in stream_engine.cpp when it attempted to
use a socket which was not connected.

I also add EINTR to mean EINPROGRESS, as per the POSIX and FreeBSD
documentation which specifies that a connect() call interrupted due to a
signal will complete asynchronously.

Signed-off-by: Martin Lucina <martin at lucina.net>
---
 src/ipc_connecter.cpp |    9 +++++----
 src/tcp_connecter.cpp |   11 ++++++-----
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/src/ipc_connecter.cpp b/src/ipc_connecter.cpp
index af3665c..0722532 100644
--- a/src/ipc_connecter.cpp
+++ b/src/ipc_connecter.cpp
@@ -133,7 +133,7 @@ void xs::ipc_connecter_t::start_connecting ()
     }
 
     //  Connection establishment may be delayed. Poll for its completion.
-    else if (rc == -1 && errno == EAGAIN) {
+    else if (rc == -1 && errno == EINPROGRESS) {
         xs_assert (!handle);
         handle = add_fd (s);
         set_pollout (handle);
@@ -196,9 +196,10 @@ int xs::ipc_connecter_t::open ()
     if (rc == 0)
         return 0;
 
-    //  Asynchronous connect was launched.
-    if (rc == -1 && errno == EINPROGRESS) {
-        errno = EAGAIN;
+    //  Translate other error codes indicating asynchronous connect has been
+    //  launched to a uniform EINPROGRESS.
+    if (rc == -1 && errno == EINTR) {
+        errno = EINPROGRESS;
         return -1;
     }
 
diff --git a/src/tcp_connecter.cpp b/src/tcp_connecter.cpp
index de105bb..5ae01e7 100644
--- a/src/tcp_connecter.cpp
+++ b/src/tcp_connecter.cpp
@@ -140,7 +140,7 @@ void xs::tcp_connecter_t::start_connecting ()
     }
 
     //  Connection establishment may be delayed. Poll for its completion.
-    else if (rc == -1 && errno == EAGAIN) {
+    else if (rc == -1 && errno == EINPROGRESS) {
         xs_assert (!handle);
         handle = add_fd (s);
         set_pollout (handle);
@@ -236,17 +236,18 @@ int xs::tcp_connecter_t::open ()
     if (rc == 0)
         return 0;
 
-    //  Asynchronous connect was launched.
+    //  Translate other error codes indicating asynchronous connect has been
+    //  launched to a uniform EINPROGRESS.
 #ifdef XS_HAVE_WINDOWS
     if (rc == SOCKET_ERROR && (WSAGetLastError () == WSAEINPROGRESS ||
           WSAGetLastError () == WSAEWOULDBLOCK)) {
-        errno = EAGAIN;
+        errno = EINPROGRESS;
         return -1;
     }    
     wsa_error_to_errno ();
 #else
-    if (rc == -1 && errno == EINPROGRESS) {
-        errno = EAGAIN;
+    if (rc == -1 && errno == EINTR) {
+        errno = EINPROGRESS;
         return -1;
     }
 #endif
-- 
1.7.10


-----------------------------------------
Full text of this topic in Crossroads Development:
http://groups.crossroads.io/r/topic/2QCfCK2pongMdlQQIzGubl

To leave Crossroads Development, email
mailto:crossroads-dev at groups.crossroads.io?Subject=unsubscribe

Start your own free groups and site with
OnlineGroups.Net http://onlinegroups.net

Host your own online groups site with
GroupServer http://groupserver.org

----- End forwarded message -----

-- 
Martin Lucina
http://lucina.net/ (interwebs/blogs/rants/consulting)
martin at lucina.net  (smtp/xmpp/jabber/gtalk)
@matolucina        (twitter)