* file_io/unix/pipe.c (file_pipe_create): Use pipe2(,O_NONBLOCK) by

  default unless APR_FULL_BLOCK was used; unconditionally set the
  blocking state later. Saves two syscalls per invocation for both
  APR_READ_BLOCK and APR_WRITE_BLOCK, no [intended] functional change.

Github: closes #56


git-svn-id: https://svn.apache.org/repos/asf/apr/apr/trunk@1918258 13f79535-47bb-0310-9956-ffa450edef68

file_io/unix/pipe.c

@@ -186,7 +186,10 @@ static apr_status_t file_pipe_create(apr_file_t **in,
     apr_interval_time_t fd_timeout;
 
 #ifdef HAVE_PIPE2
-    if (blocking == APR_FULL_NONBLOCK) {
+    /* If pipe2() is available, use O_NONBLOCK by default unless
+     * APR_FULL_BLOCK is requested, then set the individual pipe state
+     * as desired later - changing the state uses two syscalls. */
+    if (blocking != APR_FULL_BLOCK) {
         if (pipe2(filedes, O_NONBLOCK) == -1) {
             return errno;
         }
@@ -239,21 +242,14 @@ static apr_status_t file_pipe_create(apr_file_t **in,
     apr_pool_cleanup_register((*out)->pool, (void *)(*out), apr_unix_file_cleanup,
                          apr_pool_cleanup_null);
 
-    switch (blocking) {
-    case APR_FULL_BLOCK:
-        break;
-    case APR_READ_BLOCK:
-        apr_file_pipe_timeout_set(*out, 0);
-        break;
-    case APR_WRITE_BLOCK:
-        apr_file_pipe_timeout_set(*in, 0);
-        break;
-    default:
-        /* These are noops for the pipe2() case */
-        apr_file_pipe_timeout_set(*out, 0);
-        apr_file_pipe_timeout_set(*in, 0);
-        break;
-    }
+    /* Set each pipe to the desired O_NONBLOCK state, which may be a
+     * noop depending on whether the pipe2() or pipe() case was
+     * used. (timeout of -1 == blocking) */
+    apr_file_pipe_timeout_set(*in, (blocking == APR_FULL_BLOCK
+                                    || blocking == APR_READ_BLOCK) ? -1 : 0);
+    apr_file_pipe_timeout_set(*out, (blocking == APR_FULL_BLOCK
+                                     || blocking == APR_WRITE_BLOCK) ? -1 : 0);
+
     return APR_SUCCESS;
 }