Merged revisions 206706 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.4

................
  r206706 | rmudgett | 2009-07-15 15:44:55 -0500 (Wed, 15 Jul 2009) | 26 lines
  
  Merged revision 206700 from
  https://origsvn.digium.com/svn/asterisk/be/branches/C.2-...
  
  ..........
    Fixed chan_misdn crash because mISDNuser library is not thread safe.
  
    With Asterisk the mISDNuser library is driven by two threads concurrently:
    1. channels/misdn/isdn_lib.c::manager_event_handler()
    2. channels/misdn/isdn_lib.c::misdn_lib_isdn_event_catcher()
  
    Calls into the library are done concurrently and recursively from
    isdn_lib.c.
  
    Both threads can fiddle with the master/child layer3_proc_t lists.  One
    thread may traverse the list when the other interrupts it and then removes
    the list element which the first thread was currently handling.  This is
    exactly what caused the crash.  About 60 calls were needed to a Gigaset
    CX475 before it occurred once.
  
    This patch adds locking when calling into the mISDNuser library.
    This also fixes some cb_log calls with wrong port parameter.
  
    JIRA ABE-1913
        Patches: misdn-locking.patch (Modified with mostly cosmetic changes)
  ..........
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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@206707 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/misdn/isdn_lib_intern.h

@@ -65,6 +65,7 @@ struct misdn_stack {
 	/** is first element because &nst equals &mISDNlist **/
 	net_stack_t nst;
 	manager_t mgr;
+	pthread_mutex_t nstlock;
 
 	/*! \brief D Channel mISDN driver stack ID (Parent stack ID) */
 	int d_stid;