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Mark Michelson 1b91ee6c4b Fix a deadlock that occurred due to a conflict of masquerades. ... For the explanation, here is a copy-paste of the review board explanation: Initially, it was discovered that performing an attended transfer of a multiparty bridge with a PJSIP channel would cause a deadlock. A PBX thread started a masquerade and reached the point where it was calling the fixup() callback on the "original" channel. For chan_pjsip, this involves pushing a synchronous task to the session's serializer. The problem was that a task ahead of the fixup task was also attempting to perform a channel masquerade. However, since masquerades are designed in a way to only allow for one to occur at a time, the task ahead of the fixup could not continue until the masquerade already in progress had completed. And of course, the masquerade in progress could not complete until the task ahead of the fixup task had completed. Deadlock. The initial fix was to change the fixup task to be asynchronous. While this prevented the deadlock from occurring, it had the frightful side effect of potentially allowing for tasks in the session's serializer to operate on a zombie channel. Taking a step back from this particular deadlock, it became clear that the problem was not really this one particular issue but that masquerades themselves needed to be addressed. A PJSIP attended transfer operation calls ast_channel_move(), which attempts to both set up and execute a masquerade. The problem was that after it had set up the masquerade, the PBX thread had swooped in and tried to actually perform the masquerade. Looking at changes that had been made to Asterisk 12, it became clear that there never is any time now that anyone ever wants to set up a masquerade and allow for the channel thread to actually perform the masquerade. Everyone always is calling ast_channel_move(), performs the masquerade itself before returning. In this patch, I have removed all blocks of code from channel.c that will attempt to perform a masquerade if ast_channel_masq() returns true. Now, there is no distinction between setting up a masquerade and performing the masquerade. It is one operation. The only remaining checks for ast_channel_masq() and ast_channel_masqr() are in ast_hangup() since we do not want to interrupt a masquerade by hanging up the channel. Instead, now ast_hangup() will wait for a masquerade to complete before moving forward with its operation. The ast_channel_move() function has been modified to basically in-line the logic that used to be in ast_channel_masquerade(). ast_channel_masquerade() has been killed off for real. ast_channel_move() now has a lock associated with it that is used to prevent any simultaneous moves from occurring at once. This means there is no need to make sure that ast_channel_masq() or ast_channel_masqr() are already set on a channel when ast_channel_move() is called. It also means the channel container lock is not pulling double duty by both keeping the container locked and preventing multiple masquerades from occurring simultaneously. The ast_do_masquerade() function has been renamed to do_channel_masquerade() and is now internal to channel.c. The function now takes explicit arguments of which channels are involved in the masquerade instead of a single channel. While it probably is possible to do some further refactoring of this method, I feel that I would be treading dangerously. Instead, all I did was change some comments that no longer are true after this changeset. The other more minor change introduced in this patch is to res_pjsip.c to make ast_sip_push_task_synchronous() run the task in-place if we are already a SIP servant thread. This is related to this patch because even when we isolate the channel masquerade to only running in the SIP servant thread, we would still deadlock when the fixup() callback is reached since we would essentially be waiting forever for ourselves to finish before actually running the fixup. This makes it so the fixup is run without having to push a task into a serializer at all. (closes issue ASTERISK-22936) Reported by Jonathan Rose Review: https://reviewboard.asterisk.org/r/3069 ........ Merged revisions 404356 from http://svn.asterisk.org/svn/asterisk/branches/12 git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@404368 65c4cc65-6c06-0410-ace0-fbb531ad65f3		12 years ago
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editline	memory leaks: Memory leak cleanup patch by Corey Farrell (first set)	12 years ago
stdtime	Fix some uninitialized buffers for CDR handling valgrind found.	13 years ago
Makefile	Add the bucket API.	13 years ago
abstract_jb.c	Fix jitter buffer log file creation	12 years ago
acl.c	res_pjsip: AMI commands and events.	12 years ago
adsi.c	…
alaw.c	…
aoc.c	Fix documentation replication issues	13 years ago
app.c	Voicemail: Remove mailbox identifier format (box@context) assumptions in the system.	12 years ago
ast_expr2.c	…
ast_expr2.fl	…
ast_expr2.h	…
ast_expr2.y	…
ast_expr2f.c	Doxygen Updates - janitor work	13 years ago
asterisk.c	Changed the default for live_dangerously to no	12 years ago
asterisk.dynamics	…
asterisk.exports.in	Add _IO_stdin_used in version-script to fix SIGBUSes on Sparc.	13 years ago
astfd.c	Unregister CLI commands on exit	13 years ago
astmm.c	MALLOC_DEBUG: Change fence magic number to be completely different from the freed magic number.	13 years ago
astobj2.c	astobj2: Unregister debug CLI commands at exit	12 years ago
audiohook.c	ari: Add Snoop operation for spying/whispering on channels.	12 years ago
autochan.c	…
autoservice.c	Don't leak frames when memory is full in autoservice_run.	13 years ago
backtrace.c	Fix memory corruption when trying to get "core show locks".	13 years ago
bridge.c	channel locking: Add locking for channel snapshot creation	12 years ago
bridge_after.c	A great big renaming patch	13 years ago
bridge_basic.c	bridging: Give bridges a name and a known creator	12 years ago
bridge_channel.c	channel locking: Add locking for channel snapshot creation	12 years ago
bridge_roles.c	ARI: bridges/{bridgeID}/addChannel: add roles parameter	13 years ago
bucket.c	sorcery, bucket: Change observer remove calls to take const callbacks struct.	12 years ago
buildinfo.c	…
callerid.c	Allow for redirecting reasons to be set to arbitrary strings.	13 years ago
ccss.c	Cache string values of formats on ast_format_cap() to save processing.	12 years ago
cdr.c	app_cdr,app_forkcdr,func_cdr: Synchronize with engine when manipulating state	12 years ago
cel.c	channel locking: Add locking for channel snapshot creation	12 years ago
channel.c	Fix a deadlock that occurred due to a conflict of masquerades.	12 years ago
channel_internal_api.c	Remove publication of a channel snapshot when the technology is set	12 years ago
chanvars.c	ast_free() is null tollerant.	13 years ago
cli.c	Resolve some memory leaks due to incorrect for loop / ao2 ref usage.	12 years ago
config.c	config: Allow ConfBridge DTMF menus to have '#' as the first digit.	12 years ago
config_options.c	Ensure global types in the config framework are initialized	12 years ago
core_local.c	channel locking: Add locking for channel snapshot creation	12 years ago
core_unreal.c	channels: Return allocated channels locked.	12 years ago
crypt.c	Fix utils directory breakage.	13 years ago
cygload.c	…
data.c	memory leaks: Memory leak cleanup patch by Corey Farrell (second set)	12 years ago
datastore.c	This is no longer needed.	13 years ago
db.c	astdb: crash in sqlite3 during shutdown	12 years ago
devicestate.c	ARI: Implement device state API	12 years ago
dial.c	channel locking: Add locking for channel snapshot creation	12 years ago
dns.c	Remove redundant code in dns.c	13 years ago
dnsmgr.c	Migrate a large number of AMI events over to Stasis-Core	13 years ago
dsp.c	Doxygen Updates - Title update	13 years ago
ecdisa.h	…
endpoints.c	channel locking: Add locking for channel snapshot creation	12 years ago
enum.c	Migrate a large number of AMI events over to Stasis-Core	13 years ago
event.c	Fix incorrect usages of ast_realloc().	13 years ago
features.c	Restore Dial, Queue, and FollowMe 'I' option support.	13 years ago
features_config.c	Features: Rearm the parking config options have moved warning for each reload.	12 years ago
file.c	Cache string values of formats on ast_format_cap() to save processing.	12 years ago
fixedjitterbuf.c	…
fixedjitterbuf.h	…
format.c	Add pass through support for Opus and VP8; Opus format attribute negotiation	13 years ago
format_cap.c	Cache string values of formats on ast_format_cap() to save processing.	12 years ago
format_pref.c	Address uninitialized conditional that valgrind found	13 years ago
frame.c	Add pass through support for Opus and VP8; Opus format attribute negotiation	13 years ago
framehook.c	framehooks: Re-iterate if framehook provides different frame.	12 years ago
fskmodem.c	…
fskmodem_float.c	…
fskmodem_int.c	…
global_datastores.c	…
hashtab.c	Fix utilities compilation/linking.	13 years ago
heap.c	Fix incorrect usages of ast_realloc().	13 years ago
http.c	ARI: Allow specifying channel variables during a POST /channels	12 years ago
image.c	Reset automerge property.	13 years ago
indications.c	Fix incorrect usages of ast_realloc().	13 years ago
io.c	…
jitterbuf.c	jitterbuf: Fix memory leak on jitter buffer reset	12 years ago
json.c	ARI: Don't leak implementation details	12 years ago
libasteriskssl.c	Resolve memory leaks in TLS initialization and TLS client connections	14 years ago
libasteriskssl.exports.in	…
loader.c	core/loader: Don't call dlclose in a while loop	12 years ago
lock.c	Fix DEBUG_THREADS when lock is acquired in __constructor__	13 years ago
logger.c	Logging: Logging types ignored after specifying a verbose level	12 years ago
manager.c	Add AMI event for presence state.	12 years ago
manager_bridges.c	bridging: Give bridges a name and a known creator	12 years ago
manager_channels.c	Multiple revisions 399887,400138,400178,400180-400181	12 years ago
manager_endpoints.c	Multiple revisions 399887,400138,400178,400180-400181	12 years ago
manager_mwi.c	Multiple revisions 399887,400138,400178,400180-400181	12 years ago
manager_system.c	Multiple revisions 399887,400138,400178,400180-400181	12 years ago
md5.c	…
media_index.c	media_index: Make media indexing tolerable of bad symlinks.	12 years ago
message.c	channels: Return allocated channels locked.	12 years ago
mixmonitor.c	Removed quotes from svn:keywords props on a few files.	13 years ago
named_acl.c	Fix various memory leaks	13 years ago
netsock.c	Add IPv6 Support To chan_iax2	12 years ago
netsock2.c	Add IPv6 Support To chan_iax2	12 years ago
optional_api.c	optional_api: Make always use the standard malloc functions even with MALLOC_DEBUG.	12 years ago
parking.c	astobj2: Add warn unused attribute to some functions.	13 years ago
pbx.c	app_cdr,app_forkcdr,func_cdr: Synchronize with engine when manipulating state	12 years ago
pickup.c	channel locking: Add locking for channel snapshot creation	12 years ago
plc.c	…
poll.c	…
presencestate.c	Strip down the old event system	13 years ago
privacy.c	…
rtp_engine.c	Several components: fixing Typos in comments and code, "avaliable" instead of "available"	12 years ago
say.c	Add SayAlphaCase and similar functionality for AGI	13 years ago
sched.c	…
sdp_srtp.c	Merge in current pimp_my_sip work, including:	13 years ago
security_events.c	security_events: Push out security events over AMI events	12 years ago
sem.c	Multiple revisions 399887,400138,400178,400180-400181	12 years ago
sha1.c	Doxygen Updates - janitor work	13 years ago
sip_api.c	Don't make chan_sip export global symbols.	13 years ago
slinfactory.c	Fix a memory copying bug in slinfactory which was causing mixmonitor issues.	13 years ago
sorcery.c	func_pjsip_endpoint: Add PJSIP_ENDPOINT function for querying endpoint details	12 years ago
sounds_index.c	Multiple revisions 399887,400138,400178,400180-400181	12 years ago
srv.c	Removed #if checks for crazy old versions of OS X.	13 years ago
stasis.c	vector: Uppercase API to follow C convention.	12 years ago
stasis_bridges.c	channel locking: Add locking for channel snapshot creation	12 years ago
stasis_cache.c	MALLOC_DEBUG: Fix some misuses of free() when MALLOC_DEBUG is enabled.	12 years ago
stasis_cache_pattern.c	Multiple revisions 399887,400138,400178,400180-400181	12 years ago
stasis_channels.c	channel locking: Add locking for channel snapshot creation	12 years ago
stasis_endpoints.c	ARI: Don't leak implementation details	12 years ago
stasis_message.c	ARI: Don't leak implementation details	12 years ago
stasis_message_router.c	vector: Uppercase API to follow C convention.	12 years ago
stasis_system.c	Convert CCSS manager events to stasis.	13 years ago
strcompat.c	Add builtin roundf() for systems lacking it.	13 years ago
strings.c	Move ast_str_container_alloc and friends	13 years ago
stun.c	Reset automerge property.	13 years ago
syslog.c	…
taskprocessor.c	taskprocessor: Made use pthread_equal() to compare thread ids.	12 years ago
tcptls.c	security: Inhibit execution of privilege escalating functions	12 years ago
tdd.c	Doxygen Updates - janitor work	13 years ago
term.c	Revamp of terminal color codes	13 years ago
test.c	test.c: Fix too sticky unit test failed status.	12 years ago
threadpool.c	Fix threadpool rapid growth problem.	13 years ago
threadstorage.c	Unregister CLI commands on exit	13 years ago
timing.c	Reset automerge property.	13 years ago
translate.c	translate: Move freeing of frame to after it is used.	12 years ago
udptl.c	udptl: Dead code elimination. ast_udptl_bridge was not used.	12 years ago
ulaw.c	…
utils.c	res_pjsip: AMI commands and events.	12 years ago
uuid.c	Add an \extref doxygen pointer for libuuid.	13 years ago
xml.c	Detect and use xsltCleanupGlobals when available	12 years ago
xmldoc.c	func_channel, chan_pjsip: Add CHANNEL read function support for chan_pjsip	12 years ago