Fix for issue 574

src/signaler.cpp

@@ -80,13 +80,10 @@
 zmq::signaler_t::signaler_t ()
 {
     //  Create the socketpair for signaling.
-    int rc = make_fdpair (&r, &w);
-    errno_assert (rc == 0);
-
-    //  Set both fds to non-blocking mode.
-    unblock_socket (w);
-    unblock_socket (r);
-
+    if (make_fdpair (&r, &w) == 0) {
+        unblock_socket (w);
+        unblock_socket (r);
+    }
 #ifdef HAVE_FORK
     pid = getpid();
 #endif
@@ -273,7 +270,7 @@ void zmq::signaler_t::forked()
 
     // replace the file descriptors created in the parent with new
     // ones, and close the inherited ones
-    make_fdpair(&r, &w);
+    make_fdpair (&r, &w);
 #if defined ZMQ_HAVE_EVENTFD
     int rc = close (oldr);
     errno_assert (rc == 0);
@@ -286,22 +283,23 @@ void zmq::signaler_t::forked()
 }
 #endif
 
-
-
-
+//  Returns -1 if we could not make the socket pair successfully
 int zmq::signaler_t::make_fdpair (fd_t *r_, fd_t *w_)
 {
 #if defined ZMQ_HAVE_EVENTFD
-
-    // Create eventfd object.
     fd_t fd = eventfd (0, 0);
-    errno_assert (fd != -1);
-    *w_ = fd;
-    *r_ = fd;
-    return 0;
+    if (fd == -1) {
+        errno_assert (errno == ENFILE || errno == EMFILE);
+        *w_ = *r_ = -1;
+        return -1;
+    }
+    else {
+        *w_ = *r_ = fd;
+        return 0;
+    }
 
 #elif defined ZMQ_HAVE_WINDOWS
-#if !defined _WIN32_WCE
+#   if !defined _WIN32_WCE
     // Windows CE does not manage security attributes
     SECURITY_DESCRIPTOR sd;
     SECURITY_ATTRIBUTES sa;
@@ -313,7 +311,7 @@ int zmq::signaler_t::make_fdpair (fd_t *r_, fd_t *w_)
 
     sa.nLength = sizeof(SECURITY_ATTRIBUTES);
     sa.lpSecurityDescriptor = &sd;
-#endif
+#   endif
 
     //  This function has to be in a system-wide critical section so that
     //  two instances of the library don't accidentally create signaler
@@ -322,13 +320,14 @@ int zmq::signaler_t::make_fdpair (fd_t *r_, fd_t *w_)
     //  Note that if the event object already exists, the CreateEvent requests
     //  EVENT_ALL_ACCESS access right. If this fails, we try to open
     //  the event object asking for SYNCHRONIZE access only.
-#if !defined _WIN32_WCE
+#   if !defined _WIN32_WCE
     HANDLE sync = CreateEvent (&sa, FALSE, TRUE, TEXT ("Global\\zmq-signaler-port-sync"));
-#else
+#   else
     HANDLE sync = CreateEvent (NULL, FALSE, TRUE, TEXT ("Global\\zmq-signaler-port-sync"));
-#endif
+#   endif
     if (sync == NULL && GetLastError () == ERROR_ACCESS_DENIED)
-      sync = OpenEvent (SYNCHRONIZE | EVENT_MODIFY_STATE, FALSE, TEXT ("Global\\zmq-signaler-port-sync"));
+        sync = OpenEvent (SYNCHRONIZE | EVENT_MODIFY_STATE,
+                          FALSE, TEXT ("Global\\zmq-signaler-port-sync"));
 
     win_assert (sync != NULL);
 
@@ -373,13 +372,13 @@ int zmq::signaler_t::make_fdpair (fd_t *r_, fd_t *w_)
     *w_ = WSASocket (AF_INET, SOCK_STREAM, 0, NULL, 0,  0);
     wsa_assert (*w_ != INVALID_SOCKET);
 
-#if !defined _WIN32_WCE
+#   if !defined _WIN32_WCE
     //  On Windows, preventing sockets to be inherited by child processes.
     BOOL brc = SetHandleInformation ((HANDLE) *w_, HANDLE_FLAG_INHERIT, 0);
     win_assert (brc);
-#else
+#   else
     BOOL brc;
-#endif
+#   endif
 
     //  Set TCP_NODELAY on writer socket.
     rc = setsockopt (*w_, IPPROTO_TCP, TCP_NODELAY,
@@ -391,17 +390,14 @@ int zmq::signaler_t::make_fdpair (fd_t *r_, fd_t *w_)
 
     //  Save errno if connection fails
     int conn_errno = 0;
-    if (rc == SOCKET_ERROR) {
+    if (rc == SOCKET_ERROR)
         conn_errno = WSAGetLastError ();
-    } else {
+    else {
         //  Accept connection from writer.
         *r_ = accept (listener, NULL, NULL);
-
-        if (*r_ == INVALID_SOCKET) {
+        if (*r_ == INVALID_SOCKET)
             conn_errno = WSAGetLastError ();
-        }
     }
-
     //  We don't need the listening socket anymore. Close it.
     rc = closesocket (listener);
     wsa_assert (rc != SOCKET_ERROR);
@@ -415,13 +411,14 @@ int zmq::signaler_t::make_fdpair (fd_t *r_, fd_t *w_)
     win_assert (brc != 0);
 
     if (*r_ != INVALID_SOCKET) {
-#if !defined _WIN32_WCE
+#   if !defined _WIN32_WCE
         //  On Windows, preventing sockets to be inherited by child processes.
         brc = SetHandleInformation ((HANDLE) *r_, HANDLE_FLAG_INHERIT, 0);
         win_assert (brc);
-#endif
+#   endif
         return 0;
-    } else {
+    }
+    else {
         //  Cleanup writer if connection failed
         rc = closesocket (*w_);
         wsa_assert (rc != SOCKET_ERROR);
@@ -435,7 +432,6 @@ int zmq::signaler_t::make_fdpair (fd_t *r_, fd_t *w_)
         //  Unfortunately, it uses errno_assert() which gives "Unknown error"
         //  We might as well assert here and print the actual error message
         wsa_assert_no (conn_errno);
-
         return -1;
     }
 
@@ -463,7 +459,7 @@ int zmq::signaler_t::make_fdpair (fd_t *r_, fd_t *w_)
     rc = setsockopt (listener, IPPROTO_TCP, TCP_NODELACK, &on, sizeof (on));
     errno_assert (rc != -1);
 
-    rc = bind(listener, (struct sockaddr*) &lcladdr, sizeof (lcladdr));
+    rc = bind (listener, (struct sockaddr*) &lcladdr, sizeof (lcladdr));
     errno_assert (rc != -1);
 
     socklen_t lcladdr_len = sizeof (lcladdr);
@@ -493,15 +489,20 @@ int zmq::signaler_t::make_fdpair (fd_t *r_, fd_t *w_)
 
     return 0;
 
-#else // All other implementations support socketpair()
-
+#else
+    // All other implementations support socketpair()
     int sv [2];
     int rc = socketpair (AF_UNIX, SOCK_STREAM, 0, sv);
-    errno_assert (rc == 0);
-    *w_ = sv [0];
-    *r_ = sv [1];
-    return 0;
-
+    if (rc == -1) {
+        errno_assert (errno == ENFILE || errno == EMFILE);
+        sv [0] = sv [1] = -1;
+        return -1;
+    }
+    else {
+        *w_ = sv [0];
+        *r_ = sv [1];
+        return 0;
+    }
 #endif
 }
 

src/signaler.hpp

@@ -58,7 +58,8 @@ namespace zmq
         //  to pass the signals.
         static int make_fdpair (fd_t *r_, fd_t *w_);
 
-        //  Underlying write & read file descriptor.
+        //  Underlying write & read file descriptor
+        //  Will be -1 if we exceeded number of available handles
         fd_t w;
         fd_t r;
 
@@ -74,7 +75,6 @@ namespace zmq
         void close_internal();
 #endif
     };
-
 }
 
 #endif

src/socket_base.cpp

@@ -81,47 +81,49 @@ zmq::socket_base_t *zmq::socket_base_t::create (int type_, class ctx_t *parent_,
 {
     socket_base_t *s = NULL;
     switch (type_) {
-
-    case ZMQ_PAIR:
-        s = new (std::nothrow) pair_t (parent_, tid_, sid_);
-        break;
-    case ZMQ_PUB:
-        s = new (std::nothrow) pub_t (parent_, tid_, sid_);
-        break;
-    case ZMQ_SUB:
-        s = new (std::nothrow) sub_t (parent_, tid_, sid_);
-        break;
-    case ZMQ_REQ:
-        s = new (std::nothrow) req_t (parent_, tid_, sid_);
-        break;
-    case ZMQ_REP:
-        s = new (std::nothrow) rep_t (parent_, tid_, sid_);
-        break;
-    case ZMQ_DEALER:
-        s = new (std::nothrow) dealer_t (parent_, tid_, sid_);
-        break;
-    case ZMQ_ROUTER:
-        s = new (std::nothrow) router_t (parent_, tid_, sid_);
-        break;     
-    case ZMQ_PULL:
-        s = new (std::nothrow) pull_t (parent_, tid_, sid_);
-        break;
-    case ZMQ_PUSH:
-        s = new (std::nothrow) push_t (parent_, tid_, sid_);
-        break;
-    case ZMQ_XPUB:
-        s = new (std::nothrow) xpub_t (parent_, tid_, sid_);
-        break;
-    case ZMQ_XSUB:
-        s = new (std::nothrow) xsub_t (parent_, tid_, sid_);
-        break;
-    case ZMQ_STREAM:
-        s = new (std::nothrow) stream_t (parent_, tid_, sid_);
-        break;
-    default:
-        errno = EINVAL;
-        return NULL;
+        case ZMQ_PAIR:
+            s = new (std::nothrow) pair_t (parent_, tid_, sid_);
+            break;
+        case ZMQ_PUB:
+            s = new (std::nothrow) pub_t (parent_, tid_, sid_);
+            break;
+        case ZMQ_SUB:
+            s = new (std::nothrow) sub_t (parent_, tid_, sid_);
+            break;
+        case ZMQ_REQ:
+            s = new (std::nothrow) req_t (parent_, tid_, sid_);
+            break;
+        case ZMQ_REP:
+            s = new (std::nothrow) rep_t (parent_, tid_, sid_);
+            break;
+        case ZMQ_DEALER:
+            s = new (std::nothrow) dealer_t (parent_, tid_, sid_);
+            break;
+        case ZMQ_ROUTER:
+            s = new (std::nothrow) router_t (parent_, tid_, sid_);
+            break;
+        case ZMQ_PULL:
+            s = new (std::nothrow) pull_t (parent_, tid_, sid_);
+            break;
+        case ZMQ_PUSH:
+            s = new (std::nothrow) push_t (parent_, tid_, sid_);
+            break;
+        case ZMQ_XPUB:
+            s = new (std::nothrow) xpub_t (parent_, tid_, sid_);
+            break;
+        case ZMQ_XSUB:
+            s = new (std::nothrow) xsub_t (parent_, tid_, sid_);
+            break;
+        case ZMQ_STREAM:
+            s = new (std::nothrow) stream_t (parent_, tid_, sid_);
+            break;
+        default:
+            errno = EINVAL;
+            return NULL;
     }
+    if (s->mailbox.get_fd () == -1)
+        return NULL;
+
     alloc_assert (s);
     return s;
 }