[glib] gthread: add thread name support on Mac OS

[Ryan Lortie <desrt src gnome org>]

commit 2a0c18041ba71435df3fc3834d360553c97fdfe4
Author: Ilya Konstantinov <ilya konstantinov gmail com>
Date:   Sat Dec 20 11:19:00 2014 -0500

    gthread: add thread name support on Mac OS
    
    https://bugzilla.gnome.org/show_bug.cgi?id=741807

 configure.ac         |   10 ++++++++++
 glib/gthread-posix.c |    8 ++++----
 2 files changed, 14 insertions(+), 4 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index bf87fd5..7777da7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2240,6 +2240,16 @@ AS_IF([ test x"$have_threads" = xposix], [
              AC_DEFINE(HAVE_PTHREAD_COND_TIMEDWAIT_RELATIVE_NP,1,
                 [Have function pthread_cond_timedwait_relative_np])],
             [AC_MSG_RESULT(no)])
+        dnl Sets thread names on OS X 10.6, iOS 3.2 (and higher)
+        AC_MSG_CHECKING(for pthread_setname_np(const char*))
+        AC_LINK_IFELSE(
+            [AC_LANG_PROGRAM(
+                [#include <pthread.h>],
+                [pthread_setname_np("example")])],
+            [AC_MSG_RESULT(yes)
+             AC_DEFINE(HAVE_PTHREAD_SETNAME_NP_WITHOUT_TID,1,
+                [Have function pthread_setname_np(const char*)])],
+            [AC_MSG_RESULT(no)])
         CPPFLAGS="$glib_save_CPPFLAGS"
 ])
 
diff --git a/glib/gthread-posix.c b/glib/gthread-posix.c
index f4703f5..53c994e 100644
--- a/glib/gthread-posix.c
+++ b/glib/gthread-posix.c
@@ -1225,10 +1225,10 @@ g_system_thread_exit (void)
 void
 g_system_thread_set_name (const gchar *name)
 {
-#ifdef HAVE_SYS_PRCTL_H
-#ifdef PR_SET_NAME
-  prctl (PR_SET_NAME, name, 0, 0, 0, 0);
-#endif
+#if defined(HAVE_SYS_PRCTL_H) && defined(PR_SET_NAME)
+  prctl (PR_SET_NAME, name, 0, 0, 0, 0); /* on Linux */
+#elif defined(HAVE_PTHREAD_SETNAME_NP_WITHOUT_TID)
+  pthread_setname_np(name); /* on OS X and iOS */
 #endif
 }