diff --git a/src/os/unix/ngx_darwin_sendfile_chain.c b/src/os/unix/ngx_darwin_sendfile_chain.c
index e3ec7f7..59d4653 100644
--- a/src/os/unix/ngx_darwin_sendfile_chain.c
+++ b/src/os/unix/ngx_darwin_sendfile_chain.c
@@ -42,7 +42,7 @@
     u_char          *prev;
     off_t            size, send, prev_send, aligned, sent, fprev;
     off_t            header_size, file_size;
-    ngx_uint_t       eintr, eagain, complete;
+    ngx_uint_t       eintr, complete;
     ngx_err_t        err;
     ngx_buf_t       *file;
     ngx_array_t      header, trailer;
@@ -75,7 +75,6 @@
     }
 
     send = 0;
-    eagain = 0;
 
     header.elts = headers;
     header.size = sizeof(struct iovec);
@@ -238,22 +237,22 @@
             if (rc == -1) {
                 err = ngx_errno;
 
-                if (err == NGX_EAGAIN || err == NGX_EINTR) {
-                    if (err == NGX_EINTR) {
-                        eintr = 1;
+                switch (err) {
+                case NGX_EAGAIN:
+                    break;
 
-                    } else {
-                        eagain = 1;
-                    }
+                case NGX_EINTR:
+                    eintr = 1;
+                    break;
 
-                    ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, err,
-                                   "sendfile() sent only %O bytes", sent);
-
-                } else {
+                default:
                     wev->error = 1;
                     (void) ngx_connection_error(c, err, "sendfile() failed");
                     return NGX_CHAIN_ERROR;
                 }
+
+                ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, err,
+                               "sendfile() sent only %O bytes", sent);
             }
 
             if (rc == 0 && sent == 0) {
@@ -284,19 +283,22 @@
             if (rc == -1) {
                 err = ngx_errno;
 
-                if (err == NGX_EAGAIN || err == NGX_EINTR) {
-                    if (err == NGX_EINTR) {
-                        eintr = 1;
-                    }
+                switch (err) {
+                case NGX_EAGAIN:
+                    break;
 
-                    ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err,
-                                   "writev() not ready");
+                case NGX_EINTR:
+                    eintr = 1;
+                    break;
 
-                } else {
+                default:
                     wev->error = 1;
                     ngx_connection_error(c, err, "writev() failed");
                     return NGX_CHAIN_ERROR;
                 }
+
+                ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err,
+                               "writev() not ready");
             }
 
             sent = rc > 0 ? rc : 0;
diff --git a/src/os/unix/ngx_freebsd_sendfile_chain.c b/src/os/unix/ngx_freebsd_sendfile_chain.c
index c383fbe..26e3863 100644
--- a/src/os/unix/ngx_freebsd_sendfile_chain.c
+++ b/src/os/unix/ngx_freebsd_sendfile_chain.c
@@ -267,22 +267,23 @@
             if (rc == -1) {
                 err = ngx_errno;
 
-                if (err == NGX_EAGAIN || err == NGX_EINTR) {
-                    if (err == NGX_EINTR) {
-                        eintr = 1;
+                switch (err) {
+                case NGX_EAGAIN:
+                    eagain = 1;
+                    break;
 
-                    } else {
-                        eagain = 1;
-                    }
+                case NGX_EINTR:
+                    eintr = 1;
+                    break;
 
-                    ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, err,
-                                   "sendfile() sent only %O bytes", sent);
-
-                } else {
+                default:
                     wev->error = 1;
                     (void) ngx_connection_error(c, err, "sendfile() failed");
                     return NGX_CHAIN_ERROR;
                 }
+
+                ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, err,
+                               "sendfile() sent only %O bytes", sent);
             }
 
             /*
@@ -318,19 +319,22 @@
             if (rc == -1) {
                 err = ngx_errno;
 
-                if (err == NGX_EAGAIN || err == NGX_EINTR) {
-                    if (err == NGX_EINTR) {
-                        eintr = 1;
-                    }
+                switch (err) {
+                case NGX_EAGAIN:
+                    break;
 
-                    ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err,
-                                   "writev() not ready");
+                case NGX_EINTR:
+                    eintr = 1;
+                    break;
 
-                } else {
+                default:
                     wev->error = 1;
                     ngx_connection_error(c, err, "writev() failed");
                     return NGX_CHAIN_ERROR;
                 }
+
+                ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err,
+                               "writev() not ready");
             }
 
             sent = rc > 0 ? rc : 0;
diff --git a/src/os/unix/ngx_linux_sendfile_chain.c b/src/os/unix/ngx_linux_sendfile_chain.c
index e102f27..a2225d9 100644
--- a/src/os/unix/ngx_linux_sendfile_chain.c
+++ b/src/os/unix/ngx_linux_sendfile_chain.c
@@ -263,19 +263,22 @@
             if (rc == -1) {
                 err = ngx_errno;
 
-                if (err == NGX_EAGAIN || err == NGX_EINTR) {
-                    if (err == NGX_EINTR) {
-                        eintr = 1;
-                    }
+                switch (err) {
+                case NGX_EAGAIN:
+                    break;
 
-                    ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err,
-                                   "sendfile() is not ready");
+                case NGX_EINTR:
+                    eintr = 1;
+                    break;
 
-                } else {
+                default:
                     wev->error = 1;
                     ngx_connection_error(c, err, "sendfile() failed");
                     return NGX_CHAIN_ERROR;
                 }
+
+                ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err,
+                               "sendfile() is not ready");
             }
 
             sent = rc > 0 ? rc : 0;
@@ -290,19 +293,22 @@
             if (rc == -1) {
                 err = ngx_errno;
 
-                if (err == NGX_EAGAIN || err == NGX_EINTR) {
-                    if (err == NGX_EINTR) {
-                        eintr = 1;
-                    }
+                switch (err) {
+                case NGX_EAGAIN:
+                    break;
 
-                    ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err,
-                                   "writev() not ready");
+                case NGX_EINTR:
+                    eintr = 1;
+                    break;
 
-                } else {
+                default:
                     wev->error = 1;
                     ngx_connection_error(c, err, "writev() failed");
                     return NGX_CHAIN_ERROR;
                 }
+
+                ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err,
+                               "writev() not ready");
             }
 
             sent = rc > 0 ? rc : 0;
diff --git a/src/os/unix/ngx_solaris_sendfilev_chain.c b/src/os/unix/ngx_solaris_sendfilev_chain.c
index 2feae2f..3a9356c 100644
--- a/src/os/unix/ngx_solaris_sendfilev_chain.c
+++ b/src/os/unix/ngx_solaris_sendfilev_chain.c
@@ -168,19 +168,22 @@
         if (n == -1) {
             err = ngx_errno;
 
-            if (err == NGX_EAGAIN || err == NGX_EINTR) {
-                if (err == NGX_EINTR) {
-                    eintr = 1;
-                }
+            switch (err) {
+            case NGX_EAGAIN:
+                break;
 
-                ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, err,
-                              "sendfilev() sent only %uz bytes", sent);
+            case NGX_EINTR:
+                eintr = 1;
+                break;
 
-            } else {
+            default:
                 wev->error = 1;
                 ngx_connection_error(c, err, "sendfilev() failed");
                 return NGX_CHAIN_ERROR;
             }
+
+            ngx_log_debug1(NGX_LOG_DEBUG_EVENT, c->log, err,
+                          "sendfilev() sent only %uz bytes", sent);
         }
 
         ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
diff --git a/src/os/unix/ngx_writev_chain.c b/src/os/unix/ngx_writev_chain.c
index b8754cd..695cb49 100644
--- a/src/os/unix/ngx_writev_chain.c
+++ b/src/os/unix/ngx_writev_chain.c
@@ -110,19 +110,22 @@
         if (n == -1) {
             err = ngx_errno;
 
-            if (err == NGX_EAGAIN || err == NGX_EINTR) {
-                if (err == NGX_EINTR) {
-                    eintr = 1;
-                }
+            switch (err) {
+            case NGX_EAGAIN:
+                break;
 
-                ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err,
-                               "writev() not ready");
+            case NGX_EINTR:
+                eintr = 1;
+                break;
 
-            } else {
+            default:
                 wev->error = 1;
                 (void) ngx_connection_error(c, err, "writev() failed");
                 return NGX_CHAIN_ERROR;
             }
+
+            ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err,
+                           "writev() not ready");
         }
 
         sent = n > 0 ? n : 0;