* changes:
  res_pjsip_mwi: use an ao2_global object for mwi containers
  res_pjsip/res_pjsip_mwi: use centralized serializer pools

This reverts commit fd2e8d0d.

Reason for revert: Problematic for users who store their voicemail
on network storage devices, or share voicemail storage between
multiple Asterisk instances.

ASTERISK-28567 #close

Change-Id: I3ff4ca983d8e753fe2971f3439bd154705693c41

ASTERISK-28086 #close

Change-Id: Ib3baadc89b9f0477a6f25a63861433812368c5ea

On shutdown it's possible for the unsolicited mwi container to be freed before
other dependent threads are done using it. This patch ensures this can no
longer happen by wrapping the container in an ao2_global object. The solicited
container was also changed too.

ASTERISK-28552

Change-Id: I8f812286dc19a34916acacd71ce2ec26e1042047

Serializer pools have previously existed in Asterisk. However, for the most
part the code has been duplicated across modules. This patch abstracts the
code into an 'ast_serializer_pool' object. As well the code is now centralized
in serializer.c/h.

In addition serializer pools can now optionally be monitored by a shutdown
group. This will prevent the pool from being destroyed until all serializers
have completed.

Change-Id: Ib1e906144b90ffd4d5ed9826f0b719ca9c6d2971

Both res_pjsip and res_pjsip_mwi made use of serializer pools. However, they
both implemented their own serializer pool functionality that was pretty much
identical in each of the source files. This patch removes the duplicated code,
and uses the new 'ast_serializer_pool' object instead.

Additionally res_pjsip_mwi enables a shutdown group on the pool since if the
timing was right the module could be unloaded while taskprocessor threads still
needed to execute, thus causing a crash.

Change-Id: I959b0805ad024585bbb6276593118be34fbf6e1d

ASTERISK-28566 #close

Change-Id: I6daa4e5128e9406d04d3aed670c3bae98d38d40c

This avoids use of the global variable and ensures topic_all remains
active until all topics are freed.

ASTERISK-28553
patches:
  ASTERISK-28553.patch by coreyfarrell (license 5909)

Change-Id: I9a8cd8977f3c3a6aa00783f8336d2cfb9c2820f1

Add a new dialplan function PJSIP_MOH_PASSTHROUGH that allows
the on-hold behavior to be controlled on a per-call basis

ASTERISK-28542 #close

Change-Id: Iebe905b2ad6dbaa87ab330267147180b05a3c3a8

There are some warning messages which are not informative without endpoint:
"No registered subscribe handler for event presence.winfo"
"No registered publish handler for event presence"

This patch adds an endpoint name to these messages.

Change-Id: Ia2811ec226d8a12659b4f9d4d224b48289650827

ASTERISK-28544 #close

Change-Id: I8e62c444d107674c298f472e3545661de8a80dce

Original commit: cfbf5fbe

Change-Id: I34a841d73c429ca8d944481f8dccb756ee231c9c

pbx_extension_helper takes two 'context' arguments. One (con) is a
pointer directly to a 'struct ast_context' and the other (context) is
the name of the context. In all cases, one of these arguments is NULL
and the other is non-NULL.

Functions that are ultimately called by pbx_extension_helper expect that
'context' will be non-NULL, so we set it unconditionally on entry into
this function.

ASTERISK-28534 #close

Change-Id: Ifbbc5e71440afd80efd441f7a9d72e8b10b6f47d

Added "like" support for 'core show taskprocessors'. Now you
can specify a specific set of taskprocessors (or just one) by
adding the keyword "like" to the above command, followed by
your search criteria.

Change-Id: I021e740201e9ba487204b5451e46feb0e3222464

Allow the list of files to be played to be provided explicitly in the
music class's configuration. The primary driver for this change is to
allow URLs to be used for MoH.

Change-Id: I9f43b80b43880980b18b2bee26ec09429d0b92fa

If a permanent contact URI associated with an AOR is invalid, we add a
Contact header to REGISTER responses with a NULL URI, causing a crash.

ASTERISK-28463 #close

Change-Id: Id2b643e58b975bc560aab1c111e6669d54db9102

This improves the way which stasis_state reference counting works.
Since manager->states holds onto the proxy object instead of the real
object this allows stasis_state objects to be freed when appropriate
without use of a special state_remove function.  Additionally each
distinct eid associated with the state holds a reference to the state to
prevent early release and potentially allow easier debug of leaks.

Change-Id: I400e0db4b9afa3d5cb4ac7dad60907897e73f9a9

The following message:

"Subscription request from endpoint <blah> rejected. Expiration of 0 is invalid"

Would sometimes spam the log with warnings if Asterisk restarted and a bunch
of clients sent unsubscribes. This patch changes it from a warning to a debug
message.

Change-Id: I841ec42f65559f3135e037df0e55f89b6447a467

Added two new CLI commands to reset stats for taskprocessors. You can
reset stats for a single, specific taskprocessor ('core reset
taskprocessor <taskprocessor>'), or you can reset all taskprocessors
('core reset taskprocessors'). These commands will reset the counter for
the number of tasks processed as well as the max queue size.

Change-Id: Iaf17fc4ae29396ab0c6ac92408fc7bdc2f12362d

We've found a connection re-use regression in pjproject 2.9
introduced by commit
"Close #1019: Support for multiple listeners."
https://trac.pjsip.org/repos/changeset/6002
https://trac.pjsip.org/repos/ticket/1019

Normally, multiple SSL requests should reuse the same connection
if one already exists to the remote server.  When a transport
error occurs, the next request should establish a new connection
and any following requests should use that same one.  With this
patch, when a transport error occurs, every new request creates
a new connection so you can wind up with thousands of open tcp
sockets, possibly exhausting file handles, and increasing memory
usage.

Reverting pjproject commit 6002 (and related 6021) restores the
expected behavior.

We also found a memory leak in SSL processing that was introduced by
commit
"Fixed #2204: Add OpenSSL remote certificate chain info"
https://trac.pjsip.org/repos/changeset/6014
https://trac.pjsip.org/repos/ticket/2204

Apparently the remote certificate chain is continually recreated
causing the leak.

Reverting pjproject commit 6014 (and related 6022) restores the
expected behavior.

Both of these issues have been acknowledged by Teluu.

ASTERISK-28521

Change-Id: I8ae7233c3ac4ec29a3b991f738e655dabcaba9f1