replace select to poll (#584)

* replace select

* Added poll/select selection during compilation

---------

Co-authored-by: Olof Hagsand <olof@hagsand.se>

configure.ac

@@ -465,6 +465,13 @@ AH_BOTTOM([#include <clixon_custom.h>])
 
 test "x$prefix" = xNONE && prefix=$ac_default_prefix
 
+AC_ARG_ENABLE([event-poll],
+    AS_HELP_STRING([--enable-event-poll], [Enable event polling feature]),
+    [if test "$enable_event_poll" = "yes"; then
+        AC_DEFINE([CLIXON_EVENT_POLL], 1, [Enable event polling feature])
+     fi]
+)
+
 AC_CONFIG_FILES([Makefile
 	  lib/Makefile
 	  lib/src/Makefile

include/clixon_custom.h

@@ -213,8 +213,8 @@
  * This causes xml_cmp to show that the datastores are unequal and may cause a wrong diff, or
  * worse case an overwrite.
  */
-#undef SYSTEM_ONLY_CONFIG_CANDIDATE_CLEAR
 
+#undef SYSTEM_ONLY_CONFIG_CANDIDATE_CLEAR
 /*! In full XPath namespace resolve, match even if namespace not resolved
  *
  * In the case of xpath lookup functions (eg xpath_vec_ctx) where nsc is defined, then
@@ -224,3 +224,4 @@
  * This seems wrong and should be changed, but need further investigation
  */
 #define XPATH_NS_ACCEPT_UNRESOLVED
+

lib/src/clixon_event.c

@@ -69,6 +69,10 @@
 #include "clixon_options.h"
 #include "clixon_event.h"
 
+#ifdef CLIXON_EVENT_POLL
+#include <poll.h>
+#endif
+
 /*
  * Constants
  */
@@ -353,6 +357,24 @@ clixon_event_unreg_timeout(int (*fn)(int, void*),
  * @retval     0    Nothing to read/empty fd
  * @retval    -1    Error
  */
+#ifdef CLIXON_EVENT_POLL
+int
+clixon_event_poll(int fd) {
+    struct pollfd 	pfd;
+    int 			retval;
+
+    pfd.fd = fd;
+    pfd.events = POLLIN;
+
+    retval = poll(&pfd, 1, 0);
+
+    if (retval < 0) {
+        clixon_err(OE_EVENTS, errno, "poll");
+    }
+
+    return retval;
+}
+#else
 int
 clixon_event_poll(int fd)
 {
@@ -366,6 +388,7 @@ clixon_event_poll(int fd)
         clixon_err(OE_EVENTS, errno, "select");
     return retval;
 }
+#endif
 
 /*! Dispatch file descriptor events (and timeouts) by invoking callbacks.
  *