diff options
Diffstat (limited to 'include/asterisk')
| -rw-r--r-- | include/asterisk/autochan.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/include/asterisk/autochan.h b/include/asterisk/autochan.h index a0981b7c9..319c203ab 100644 --- a/include/asterisk/autochan.h +++ b/include/asterisk/autochan.h @@ -56,8 +56,28 @@ struct ast_autochan { * to save off the pointer using ast_channel_ref and to unref the channel when you * are finished with the pointer. If you do not do this and a masquerade occurs on * the channel, then it is possible that your saved pointer will become invalid. + * + * 3. If you want to lock the autochan->chan channel, be sure to use + * ast_autochan_channel_lock and ast_autochan_channel_unlock. An attempt to lock + * the autochan->chan directly may result in it being changed after you've + * retrieved the value of chan, but before you've had a chance to lock it. + * First when chan is locked, the autochan structure is guaranteed to keep the + * same channel. */ +#define ast_autochan_channel_lock(autochan) \ + do { \ + struct ast_channel *autochan_chan = autochan->chan; \ + ast_channel_lock(autochan_chan); \ + if (autochan->chan == autochan_chan) { \ + break; \ + } \ + ast_channel_unlock(autochan_chan); \ + } while (1) + +#define ast_autochan_channel_unlock(autochan) \ + ast_channel_unlock(autochan->chan) + /*! * \brief set up a new ast_autochan structure * |