Merge pull request #550 from JonDyte/iovec

Experimental function zmq_recviov doesnt work correctly in a couple of c...

src/zmq.cpp

@@ -478,10 +478,6 @@ int zmq_recv (void *s_, void *buf_, size_t len_, int flags_)
 // The iov_base* buffers of each iovec *a_ filled in by this 
 // function may be freed using free().
 //
-// Implementation note: We assume zmq::msg_t buffer allocated
-// by zmq::recvmsg can be freed by free().
-// We assume it is safe to steal these buffers by simply
-// not closing the zmq::msg_t.
 //
 int zmq_recviov (void *s_, iovec *a_, size_t *count_, int flags_)
 {
@@ -498,8 +494,7 @@ int zmq_recviov (void *s_, iovec *a_, size_t *count_, int flags_)
     *count_ = 0;
 
     for (size_t i = 0; recvmore && i < count; ++i) {
-        // Cheat! We never close any msg
-        // because we want to steal the buffer.
+
         zmq_msg_t msg;
         int rc = zmq_msg_init (&msg);
         errno_assert (rc == 0);
@@ -513,15 +508,21 @@ int zmq_recviov (void *s_, iovec *a_, size_t *count_, int flags_)
             nread = -1;
             break;
         }
-        ++*count_;
-        ++nread;
 
-        // Cheat: acquire zmq_msg buffer.
-        a_[i].iov_base = static_cast<char *> (zmq_msg_data (&msg));
         a_[i].iov_len = zmq_msg_size (&msg);
-
+        a_[i].iov_base = malloc(a_[i].iov_len);
+        if (!a_[i].iov_base) {
+            errno = ENOMEM;
+            return -1;
+        }
+        memcpy(a_[i].iov_base,static_cast<char *> (zmq_msg_data (&msg)),
+               a_[i].iov_len);
         // Assume zmq_socket ZMQ_RVCMORE is properly set.
         recvmore = ((zmq::msg_t*) (void *) &msg)->flags () & zmq::msg_t::more;
+        rc = zmq_msg_close(&msg);
+        errno_assert (rc == 0);
+        ++*count_;
+        ++nread;
     }
     return nread;
 }

tests/Makefile.am

@@ -20,7 +20,8 @@ noinst_PROGRAMS = test_pair_inproc \
                   test_router_mandatory \
                   test_raw_sock \
                   test_disconnect_inproc \
-                  test_ctx_options
+                  test_ctx_options \
+				  test_iov
 
 if !ON_MINGW
 noinst_PROGRAMS += test_shutdown_stress \

tests/test_iov.cpp

@@ -0,0 +1,111 @@
+/*
+    Copyright (c) 2007-2013 Contributors as noted in the AUTHORS file
+
+    This file is part of 0MQ.
+
+    0MQ is free software; you can redistribute it and/or modify it under
+    the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    0MQ is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "../include/zmq.h"
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#undef NDEBUG
+#include <assert.h>
+
+// XSI vector I/O
+#if defined ZMQ_HAVE_UIO
+#include <sys/uio.h>
+#else
+struct iovec {
+    void *iov_base;
+    size_t iov_len;
+};
+#endif
+
+void do_check(void* sb, void* sc, unsigned int msgsz)
+{
+    int rc;
+    int sum =0;
+    for (int i = 0; i < 10; i++)
+    {
+        zmq_msg_t msg;
+        zmq_msg_init_size(&msg, msgsz);
+        void * data = zmq_msg_data(&msg);
+        memcpy(data,&i, sizeof(int));
+        rc = zmq_msg_send(&msg,sc,i==9 ? 0 :ZMQ_SNDMORE);
+        assert (rc == (int)msgsz);
+        zmq_msg_close(&msg);
+        sum += i;
+    }
+
+    struct iovec ibuffer[32] ;
+    memset(&ibuffer[0], 0, sizeof(ibuffer));
+
+    size_t count = 10;
+    rc = zmq_recviov(sb,&ibuffer[0],&count,0);
+    assert (rc == 10);
+
+    int rsum=0;
+    for(;count;--count)
+    {
+        int v;
+        memcpy(&v,ibuffer[count-1].iov_base,sizeof(int));
+        rsum += v;
+        assert(ibuffer[count-1].iov_len == msgsz);
+        // free up the memory
+        free(ibuffer[count-1].iov_base);
+    }
+
+    assert ( sum == rsum );
+
+}
+
+int main (void)
+{
+    void *ctx = zmq_ctx_new ();
+    assert (ctx);
+    int rc;
+
+    void *sb = zmq_socket (ctx, ZMQ_PULL);
+    assert (sb);
+
+    rc = zmq_bind (sb, "inproc://a");
+    assert (rc == 0);
+
+    ::sleep(1);
+    void *sc = zmq_socket (ctx, ZMQ_PUSH);
+
+    rc = zmq_connect (sc, "inproc://a");
+    assert (rc == 0);
+
+
+    // message bigger than vsm max
+    do_check(sb,sc,100);
+
+    // message smaller than vsm max
+    do_check(sb,sc,10);
+
+    rc = zmq_close (sc);
+    assert (rc == 0);
+
+    rc = zmq_close (sb);
+    assert (rc == 0);
+
+    rc = zmq_ctx_term (ctx);
+    assert (rc == 0);
+
+	return 0;
+}