diff options
author | Richard Mudgett <rmudgett@digium.com> | 2011-09-26 19:40:12 +0000 |
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committer | Richard Mudgett <rmudgett@digium.com> | 2011-09-26 19:40:12 +0000 |
commit | 55b70ae6259a85239d5b983424d9d1b6588d8ab7 (patch) | |
tree | 2d6350156336b0167284d100cb9872f8b2a1ba21 /include/asterisk/channel.h | |
parent | 6a0fa4e321a8252000f7abec8bc056f223012cf7 (diff) |
Merged revisions 337974 via svnmerge from
https://origsvn.digium.com/svn/asterisk/branches/10
................
r337974 | rmudgett | 2011-09-26 14:35:23 -0500 (Mon, 26 Sep 2011) | 37 lines
Merged revisions 337973 via svnmerge from
https://origsvn.digium.com/svn/asterisk/branches/1.8
........
r337973 | rmudgett | 2011-09-26 14:30:39 -0500 (Mon, 26 Sep 2011) | 30 lines
Fix deadlock when using dummy channels.
Dummy channels created by ast_dummy_channel_alloc() should be destoyed by
ast_channel_unref(). Using ast_channel_release() needlessly grabs the
channel container lock and can cause a deadlock as a result.
* Analyzed use of ast_dummy_channel_alloc() and made use
ast_channel_unref() when done with the dummy channel. (Primary reason for
the reported deadlock.)
* Made app_dial.c:dial_exec_full() not call ast_call() holding any channel
locks. Chan_local could not perform deadlock avoidance correctly.
(Potential deadlock exposed by this issue. Secondary reason for the
reported deadlock since the held lock was part of the deadlock chain.)
* Fixed some uses of ast_dummy_channel_alloc() not checking the returned
channel pointer for failure.
* Fixed some potential chan=NULL pointer usage in func_odbc.c. Protected
by testing the bogus_chan value.
* Fixed needlessly clearing a 1024 char auto array when setting the first
char to zero is enough in manager.c:action_getvar().
(closes issue ASTERISK-18613)
Reported by: Thomas Arimont
Patches:
jira_asterisk_18613_v1.8.patch (license #5621) patch uploaded by rmudgett
Tested by: Thomas Arimont
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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@337975 65c4cc65-6c06-0410-ace0-fbb531ad65f3
Diffstat (limited to 'include/asterisk/channel.h')
-rw-r--r-- | include/asterisk/channel.h | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/include/asterisk/channel.h b/include/asterisk/channel.h index 44f0a20f3..4d25f66e6 100644 --- a/include/asterisk/channel.h +++ b/include/asterisk/channel.h @@ -1134,6 +1134,7 @@ struct ast_channel * attribute_malloc __attribute__((format(printf, 13, 14))) __ast_channel_alloc(needqueue, state, cid_num, cid_name, acctcode, exten, context, linkedid, amaflag, \ __FILE__, __LINE__, __FUNCTION__, __VA_ARGS__) +#if defined(REF_DEBUG) || defined(__AST_DEBUG_MALLOC) /*! * \brief Create a fake channel structure * @@ -1143,11 +1144,32 @@ struct ast_channel * attribute_malloc __attribute__((format(printf, 13, 14))) * \note This function should ONLY be used to create a fake channel * that can then be populated with data for use in variable * substitution when a real channel does not exist. + * + * \note The created dummy channel should be destroyed by + * ast_channel_unref(). Using ast_channel_release() needlessly + * grabs the channel container lock and can cause a deadlock as + * a result. Also grabbing the channel container lock reduces + * system performance. */ -#if defined(REF_DEBUG) || defined(__AST_DEBUG_MALLOC) #define ast_dummy_channel_alloc() __ast_dummy_channel_alloc(__FILE__, __LINE__, __PRETTY_FUNCTION__) struct ast_channel *__ast_dummy_channel_alloc(const char *file, int line, const char *function); #else +/*! + * \brief Create a fake channel structure + * + * \retval NULL failure + * \retval non-NULL successfully allocated channel + * + * \note This function should ONLY be used to create a fake channel + * that can then be populated with data for use in variable + * substitution when a real channel does not exist. + * + * \note The created dummy channel should be destroyed by + * ast_channel_unref(). Using ast_channel_release() needlessly + * grabs the channel container lock and can cause a deadlock as + * a result. Also grabbing the channel container lock reduces + * system performance. + */ struct ast_channel *ast_dummy_channel_alloc(void); #endif @@ -1593,6 +1615,7 @@ int __ast_answer(struct ast_channel *chan, unsigned int delay, int cdr_answer); /*! * \brief Make a call + * \note Absolutely _NO_ channel locks should be held before calling this function. * \param chan which channel to make the call on * \param addr destination of the call * \param timeout time to wait on for connect |