diff --git a/src/os/unix/ngx_freebsd_sendfile_chain.c b/src/os/unix/ngx_freebsd_sendfile_chain.c
index b435625..c241499 100644
--- a/src/os/unix/ngx_freebsd_sendfile_chain.c
+++ b/src/os/unix/ngx_freebsd_sendfile_chain.c
@@ -25,8 +25,8 @@
 {
     int              rc, eintr, eagain;
     char            *prev;
-    ssize_t          hsize, fsize, size;
     off_t            sent, fprev;
+    ssize_t          hsize, fsize, size;
     struct iovec    *iov;
     struct sf_hdtr   hdtr;
     ngx_err_t        err;
@@ -67,15 +67,14 @@
 
             if (prev == cl->hunk->pos) {
                 iov->iov_len += cl->hunk->last - cl->hunk->pos;
-                prev = cl->hunk->last;
 
             } else {
                 ngx_test_null(iov, ngx_push_array(&header), NGX_CHAIN_ERROR);
                 iov->iov_base = cl->hunk->pos;
                 iov->iov_len = cl->hunk->last - cl->hunk->pos;
-                prev = cl->hunk->last;
             }
 
+            prev = cl->hunk->last;
             hsize += cl->hunk->last - cl->hunk->pos;
         }
 
@@ -118,14 +117,14 @@
 
             if (prev == cl->hunk->pos) {
                 iov->iov_len += cl->hunk->last - cl->hunk->pos;
-                prev = cl->hunk->last;
 
             } else {
                 ngx_test_null(iov, ngx_push_array(&trailer), NGX_CHAIN_ERROR);
                 iov->iov_base = cl->hunk->pos;
                 iov->iov_len = cl->hunk->last - cl->hunk->pos;
-                prev = cl->hunk->last;
             }
+
+            prev = cl->hunk->last;
         }
 
         /*
@@ -182,6 +181,7 @@
                                   "sendfile() sent only %qd bytes", sent);
 
                 } else {
+                    c->write->error = 1;
                     ngx_log_error(NGX_LOG_CRIT, c->log, err,
                                   "sendfile() failed");
                     return NGX_CHAIN_ERROR;
@@ -206,6 +206,7 @@
                     ngx_log_error(NGX_LOG_INFO, c->log, err, "writev() EINTR");
 
                 } else {
+                    c->write->error = 1;
                     ngx_log_error(NGX_LOG_CRIT, c->log, err, "writev() failed");
                     return NGX_CHAIN_ERROR;
                 }
diff --git a/src/os/unix/ngx_readv_chain.c b/src/os/unix/ngx_readv_chain.c
index c83b076..f195698 100644
--- a/src/os/unix/ngx_readv_chain.c
+++ b/src/os/unix/ngx_readv_chain.c
@@ -6,23 +6,30 @@
 
 ssize_t ngx_readv_chain(ngx_connection_t *c, ngx_chain_t *chain)
 {
+    char          *prev;
     ssize_t        n;
     struct iovec  *iov;
     ngx_err_t      err;
     ngx_array_t    io;
 
-#if (NGX_SUPPRESS_WARN)
+    prev = NULL;
     iov = NULL;
-#endif
 
     ngx_init_array(io, c->pool, 10, sizeof(struct iovec), NGX_ERROR);
 
-    /* TODO: coalesce the neighbouring chain entries */
+    /* coalesce the neighbouring hunks */
 
     while (chain) {
-        ngx_test_null(iov, ngx_push_array(&io), NGX_ERROR);
-        iov->iov_base = chain->hunk->last;
-        iov->iov_len = chain->hunk->end - chain->hunk->last;
+        if (prev == chain->hunk->last) {
+            iov->iov_len += chain->hunk->end - chain->hunk->last;
+
+        } else {
+            ngx_test_null(iov, ngx_push_array(&io), NGX_ERROR);
+            iov->iov_base = chain->hunk->last;
+            iov->iov_len = chain->hunk->end - chain->hunk->last;
+        }
+
+        prev = chain->hunk->end;
         chain = chain->next;
     }
 
@@ -30,8 +37,12 @@
 
     n = readv(c->fd, (struct iovec *) io.elts, io.nelts);
 
-    if (n == -1) {
+    if (n == 0) {
+        c->read->eof = 1;
+
+    } else if (n == -1) {
         c->read->ready = 0;
+        c->read->error = 1;
 
         err = ngx_errno;
         if (err == NGX_EAGAIN) {
diff --git a/src/os/unix/ngx_recv.c b/src/os/unix/ngx_recv.c
index e61cc33..1a14fd9 100644
--- a/src/os/unix/ngx_recv.c
+++ b/src/os/unix/ngx_recv.c
@@ -18,15 +18,19 @@
 
     if (ngx_event_flags & NGX_HAVE_KQUEUE_EVENT) {
         ngx_log_debug(c->log, "recv: eof:%d, avail:%d, err:%d" _
-                      rev->eof _ rev->available _ rev->error);
+                      rev->kq_eof _ rev->available _ rev->kq_errno);
 
         if (rev->available == 0) {
-            if (rev->eof) {
+            if (rev->kq_eof) {
                 rev->ready = 0;
-                if (rev->error) {
-                    ngx_set_socket_errno(rev->error);
-                    return ngx_unix_recv_error(rev, rev->error);
+                rev->eof = 1;
+
+                if (rev->kq_errno) {
+                    rev->error = 1;
+                    ngx_set_socket_errno(rev->kq_errno);
+                    return ngx_unix_recv_error(rev, rev->kq_errno);
                 }
+
                 return 0;
 
             } else {
@@ -43,8 +47,14 @@
         if (n >= 0) {
             if (ngx_event_flags & NGX_HAVE_KQUEUE_EVENT) {
                 rev->available -= n;
+
+                /*
+                 * rev->available can be negative here because some additional
+                 * bytes can be received between kevent() and recv()
+                 */
+
                 if (rev->available <= 0) {
-                    if (!rev->eof) {
+                    if (!rev->kq_eof) {
                         rev->ready = 0;
                     }
 
@@ -60,10 +70,15 @@
                 rev->ready = 0;
             }
 
+            if (n == 0) {
+                rev->eof = 1;
+            }
+
             return n;
         }
 
         rev->ready = 0;
+        rev->error = 1;
         n = ngx_unix_recv_error(rev, ngx_socket_errno);
 
     } while (n == NGX_EINTR);
@@ -89,10 +104,16 @@
             if ((size_t) n < size) {
                 rev->ready = 0;
             }
+
+            if (n == 0) {
+                rev->eof = 1;
+            }
+
             return n;
         }
 
         rev->ready = 0;
+        rev->error = 1;
         n = ngx_unix_recv_error(rev, ngx_socket_errno);
 
     } while (n == NGX_EINTR);