Closed ticket #1107: iOS4 background feature

 * pjlib:
  * add support for activesock TCP to work in background mode.
  * add feature in ioqueue to recreate closed UDP sockets.
 * pjsip-apps:
  * ipjsua: add support for iPhone OS 4 background mode
  * ipjsystest: add support for iPhone OS 4 background mode



git-svn-id: https://svn.pjsip.org/repos/pjproject/trunk@3299 74dad513-b988-da41-8d7b-12977e46ad98
diff --git a/pjlib/include/pj/activesock.h b/pjlib/include/pj/activesock.h
index c7fc908..1ebb5a2 100644
--- a/pjlib/include/pj/activesock.h
+++ b/pjlib/include/pj/activesock.h
@@ -302,6 +302,21 @@
  */
 PJ_DECL(pj_status_t) pj_activesock_close(pj_activesock_t *asock);
 
+#if defined(PJ_IPHONE_OS_HAS_MULTITASKING_SUPPORT) && \
+    PJ_IPHONE_OS_HAS_MULTITASKING_SUPPORT!=0
+/**
+ * Set iPhone OS background mode setting. Setting to 1 will enable TCP
+ * active socket to receive incoming data when application is in the
+ * background. Setting to 0 will disable it. Default value of this
+ * setting is PJ_ACTIVESOCK_TCP_IPHONE_OS_BG.
+ *
+ * @param asock	    The active socket.
+ * @param val	    The value of background mode setting.
+ *
+ */
+PJ_DECL(void) pj_activesock_set_iphone_os_bg(pj_activesock_t *asock,
+					     int val);
+#endif
 
 /**
  * Associate arbitrary data with the active socket. Application may