15 Commits (138cd8d01944fb5bdff6b47fc641e29d4c0c5139)

Author	SHA1	Message	Date
David M. Lee	2de42c2a25	Multiple revisions 399887,400138,400178,400180-400181 ... ........ r399887 | dlee | 2013-09-26 10:41:47 -0500 (Thu, 26 Sep 2013) | 1 line Minor performance bump by not allocate manager variable struct if we don't need it ........ r400138 | dlee | 2013-09-30 10:24:00 -0500 (Mon, 30 Sep 2013) | 23 lines Stasis performance improvements This patch addresses several performance problems that were found in the initial performance testing of Asterisk 12. The Stasis dispatch object was allocated as an AO2 object, even though it has a very confined lifecycle. This was replaced with a straight ast_malloc(). The Stasis message router was spending an inordinate amount of time searching hash tables. In this case, most of our routers had 6 or fewer routes in them to begin with. This was replaced with an array that's searched linearly for the route. We more heavily rely on AO2 objects in Asterisk 12, and the memset() in ao2_ref() actually became noticeable on the profile. This was #ifdef'ed to only run when AO2_DEBUG was enabled. After being misled by an erroneous comment in taskprocessor.c during profiling, the wrong comment was removed. Review: https://reviewboard.asterisk.org/r/2873/ ........ r400178 | dlee | 2013-09-30 13:26:27 -0500 (Mon, 30 Sep 2013) | 24 lines Taskprocessor optimization; switch Stasis to use taskprocessors This patch optimizes taskprocessor to use a semaphore for signaling, which the OS can do a better job at managing contention and waiting that we can with a mutex and condition. The taskprocessor execution was also slightly optimized to reduce the number of locks taken. The only observable difference in the taskprocessor implementation is that when the final reference to the taskprocessor goes away, it will execute all tasks to completion instead of discarding the unexecuted tasks. For systems where unnamed semaphores are not supported, a really simple semaphore implementation is provided. (Which gives identical performance as the original taskprocessor implementation). The way we ended up implementing Stasis caused the threadpool to be a burden instead of a boost to performance. This was switched to just use taskprocessors directly for subscriptions. Review: https://reviewboard.asterisk.org/r/2881/ ........ r400180 | dlee | 2013-09-30 13:39:34 -0500 (Mon, 30 Sep 2013) | 28 lines Optimize how Stasis forwards are dispatched This patch optimizes how forwards are dispatched in Stasis. Originally, forwards were dispatched as subscriptions that are invoked on the publishing thread. This did not account for the vast number of forwards we would end up having in the system, and the amount of work it would take to walk though the forward subscriptions. This patch modifies Stasis so that rather than walking the tree of forwards on every dispatch, when forwards and subscriptions are changed, the subscriber list for every topic in the tree is changed. This has a couple of benefits. First, this reduces the workload of dispatching messages. It also reduces contention when dispatching to different topics that happen to forward to the same aggregation topic (as happens with all of the channel, bridge and endpoint topics). Since forwards are no longer subscriptions, the bulk of this patch is simply changing stasis_subscription objects to stasis_forward objects (which, admittedly, I should have done in the first place.) Since this required me to yet again put in a growing array, I finally abstracted that out into a set of ast_vector macros in asterisk/vector.h. Review: https://reviewboard.asterisk.org/r/2883/ ........ r400181 | dlee | 2013-09-30 13:48:57 -0500 (Mon, 30 Sep 2013) | 28 lines Remove dispatch object allocation from Stasis publishing While looking for areas for performance improvement, I realized that an unused feature in Stasis was negatively impacting performance. When a message is sent to a subscriber, a dispatch object is allocated for the dispatch, containing the topic the message was published to, the subscriber the message is being sent to, and the message itself. The topic is actually unused by any subscriber in Asterisk today. And the subscriber is associated with the taskprocessor the message is being dispatched to. First, this patch removes the unused topic parameter from Stasis subscription callbacks. Second, this patch introduces the concept of taskprocessor local data, data that may be set on a taskprocessor and provided along with the data pointer when a task is pushed using the ast_taskprocessor_push_local() call. This allows the task to have both data specific to that taskprocessor, in addition to data specific to that invocation. With those two changes, the dispatch object can be removed completely, and the message is simply refcounted and sent directly to the taskprocessor. Review: https://reviewboard.asterisk.org/r/2884/ ........ Merged revisions 399887,400138,400178,400180-400181 from http://svn.asterisk.org/svn/asterisk/branches/12 git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@400186 65c4cc65-6c06-0410-ace0-fbb531ad65f3	12 years ago
David M. Lee	222e8a3afb	Add a serializer interface to the threadpool ... This patch adds the ability to create a serializer from a thread pool. A serializer is a ast_taskprocessor with the same contract as a default taskprocessor (tasks execute serially) except instead of executing out of a dedicated thread, execution occurs in a thread from a ast_threadpool. Think of it as a lightweight thread. While it guarantees that each task will complete before executing the next, there is no guarantee as to which thread from the pool individual tasks will execute. This normally only matters if your code relys on thread specific information, such as thread locals. This patch also fixes a bug in how the 'was_empty' parameter is computed for the push callback, and gets rid of the unused 'shutting_down' field. Review: https://reviewboard.asterisk.org/r/2323/ git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@381326 65c4cc65-6c06-0410-ace0-fbb531ad65f3	12 years ago
Mark Michelson	84c50fde1f	Address David's latest feedback on reviewboard: ... * Add a max_size option for threadpools. Also added a test for this option. * Fixed comments to be more accurate and have fewer typos. * Updated copyright dates on new files. git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@379375 65c4cc65-6c06-0410-ace0-fbb531ad65f3	12 years ago
Mark Michelson	663479a558	Make ast_taskprocessor_listener opaque. ... git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@379125 65c4cc65-6c06-0410-ace0-fbb531ad65f3	12 years ago
Mark Michelson	65c7d6e2c3	Remove alloc and destroy callbacks from the taskprocessor. ... Now user data is allocated by the creator of the taskprocessor listener and that user data is passed into ast_taskprocessor_listener_alloc(). Similarly, freeing of the user data is left up to the user himself. He can free the data when the taskprocessor shuts down, or he can choose to hold onto it if it makes sense to do so. This, unsurprisingly, makes threadpool allocation a LOT cleaner now. git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@379120 65c4cc65-6c06-0410-ace0-fbb531ad65f3	12 years ago
Mark Michelson	4590bfd93d	Add new threadpool test and fix some taskprocessor bugs. ... The new thread creation test fails because Asterisk locks up while trying to lock a taskprocessor. While trying to debug that, I found a race condition during taskprocessor creation where a default taskprocessor listener could try to operate on a partially started taskprocessor. This was fixed by adding a new callback to taskprocessor listeners. Then while testing that change, I found some bugs in the taskprocessor tests where I was not properly unlocking when done with a lock. Scoped locks have spoiled me a bit. I still have not figured out why the threadpool thread creation test is locking up. git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@377368 65c4cc65-6c06-0410-ace0-fbb531ad65f3	13 years ago
Mark Michelson	ff06346ea2	Add doxygen to taskprocessor tests. ... git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@376498 65c4cc65-6c06-0410-ace0-fbb531ad65f3	13 years ago
Mark Michelson	623d741ba1	Restructure taskprocessor load test to test integrity of task execution. ... This throws a random number to each task and stores a copy locally. After all tasks have executed, the data is checked to be sure tasks executed in the correct order. git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@376413 65c4cc65-6c06-0410-ace0-fbb531ad65f3	13 years ago
Mark Michelson	da0e2169de	Add a second default taskprocessor test that executes 20000 tasks. ... git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@376412 65c4cc65-6c06-0410-ace0-fbb531ad65f3	13 years ago
Mark Michelson	f209bc6f9d	Change the default taskprocessor test so it will never hang forever. ... Changes the ast_cond_wait() to an ast_cond_timedwait() so that if there is an issue, we'll never wait forever for the task to finish execution. git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@376411 65c4cc65-6c06-0410-ace0-fbb531ad65f3	13 years ago
Mark Michelson	ec68a15619	Test that shutdown callback is called when expected. ... git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@376383 65c4cc65-6c06-0410-ace0-fbb531ad65f3	13 years ago
Mark Michelson	12de4198b8	Add a shutdown callback to taskprocessor listeners. ... This helps account for the fact that it is unknown just how many references may exist for a given taskprocessor listener, so simply unreffing it from the taskprocessor shutdown function is not enough to convey the gravity of the situation. By putting in a shutdown callback, it now becomes clear to the listener not to try to do any further operations on the taskprocessor. git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@376381 65c4cc65-6c06-0410-ace0-fbb531ad65f3	13 years ago
Mark Michelson	426e8d1454	Refine the taskprocessor listener test a bit more. ... This makes it easier to follow and tests more thoroughly. git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@376140 65c4cc65-6c06-0410-ace0-fbb531ad65f3	13 years ago
Mark Michelson	7d84963667	Add a test that ensures that taskprocessor listener callbacks ... are properly called. The new test is a bit raw in that it uses magic numbers, but that can be improved upon easily. git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@376124 65c4cc65-6c06-0410-ace0-fbb531ad65f3	13 years ago
Mark Michelson	6fc8d830f8	Add a basic taskprocessor test. ... This just queues a task and ensures that the task gets executed by the default taskprocessor listener. git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@376120 65c4cc65-6c06-0410-ace0-fbb531ad65f3	13 years ago