Add some documentation detailing an aspect of dialplan functions, as requested by...

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@77838 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/CHANGES b/CHANGES
index b43b2442db13719bae56edf521bbf739acf363ec..35588656e6866f9ca15ac7b2224cfd602816afdb 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -33,6 +33,10 @@ Dialplan functions
   * MailboxExists converted to dialplan function
   * A new option to Dial() for telling IP phones not to count the call
     as "missed" when dial times out and cancels.
+  * Added LOCK(), TRYLOCK(), and UNLOCK(), which provide a single level dialplan
+    mutex.  No deadlocks are possible, as LOCK() only allows a single lock to be
+    held for any given channel.  Also, locks are automatically freed when a
+    channel is hung up.
 
 CLI Changes
 -----------

diff --git a/funcs/func_lock.c b/funcs/func_lock.c
index 477f1c1aa3ca858f6f211a2b49a0da39f59199f1..e9ac0651b84fe1e4a027967aab8b4711873e7773 100644 (file)
--- a/funcs/func_lock.c
+++ b/funcs/func_lock.c
@@ -200,8 +200,9 @@ static struct ast_custom_function unlock_function = {
        .name = "UNLOCK",
        .synopsis = "Unlocks a named mutex",
        .desc =
-"Unlocks a previously locked mutex.  Returns 1 if the channel had a lock\n"
-"or 0 otherwise.\n",
+"Unlocks a previously locked mutex.  Note that it is generally unnecessary to\n"
+"unlock in a hangup routine, as any lock held is automatically freed when the\n"
+"channel is destroyed.  Returns 1 if the channel had a lock or 0 otherwise.\n",
        .syntax = "UNLOCK()",
        .read = unlock_read,
 };