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path: root/indra/llcommon/workqueue.cpp
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2021-11-04SL-16202: Merge branch 'sl-16220' into glthreadNat Goodspeed
2021-10-26SL-16220: Change WorkQueue::runOn() to waitForResult().Nat Goodspeed
In addition to the name making the blocking explicit, we changed the signature: instead of specifying a target WorkQueue on which to run, waitForResult() runs the passed callable on its own WorkQueue. Why is that? Because, unlike postTo(), we do not require a handshake between two different WorkQueues. postTo() allows running arbitrary callback code, setting variables or whatever, on the originating WorkQueue (presumably on the originating thread). waitForResult() synchronizes using Promise/Future, which are explicitly designed for cross-thread communication. We need not call set_value() on the originating thread, so we don't need a postTo() callback lambda.
2021-10-25SL-16220: WorkQueue::runOn() methods submit work, wait for result.Nat Goodspeed
The idea is that you can call runOn(target, callable) from a (non-default) coroutine and block that coroutine until the result becomes available. As a safety check, we forbid calling runOn() from a thread's default coroutine, assuming that a given thread's default coroutine is the one servicing the relevant WorkQueue.
2021-10-22SL-16220: Add LL::ThreadPool class and a "General" instance.Nat Goodspeed
ThreadPool bundles a WorkQueue with the specified number of worker threads to service it. Each ThreadPool has a name that can be used to locate its WorkQueue. Each worker thread calls WorkQueue::runUntilClose(). ThreadPool listens on the "LLApp" LLEventPump for shutdown notification. On receiving that, it closes its WorkQueue and then join()s each of its worker threads for orderly shutdown. Add a settings.xml entry "ThreadPoolSizes", the first LLSD-valued settings entry to expect a map: pool name->size. The expectation is that usually code instantiating a particular ThreadPool will have a default size in mind, but it should check "ThreadPoolSizes" for a user override. Make idle_startup()'s STATE_SEED_CAP_GRANTED state instantiate a "General" ThreadPool. This is function-static for lazy initialization. Eliminate LLMainLoopRepeater, which is completely unreferenced. Any potential future use cases are better addressed by posting to the main loop's WorkQueue. Eliminate llappviewer.cpp's private LLDeferredTaskList class, which implemented LLAppViewer::addOnIdleCallback(). Make addOnIdleCallback() post work to the main loop's WorkQueue instead.
2021-10-21SL-16202 Fix for textures appearing black or flashing white due to ↵Dave Parks
optimization bugs.
2021-10-07SL-16024: Defend against two threads making "anonymous" WorkQueues.Nat Goodspeed
Also make workqueue_test.cpp more robust.
2021-10-07SL-16024: Add LL::WorkQueue for passing work items between threads.Nat Goodspeed
A typical WorkQueue has a string name, which can be used to find it to post work to it. "Work" is a nullary callable. WorkQueue is a multi-producer, multi-consumer thread-safe queue: multiple threads can service the WorkQueue, multiple threads can post work to it. Work can be scheduled in the future by submitting with a timestamp. In addition, a given work item can be scheduled to run on a recurring basis. A requesting thread servicing a WorkQueue of its own, such as the viewer's main thread, can submit work to another WorkQueue along with a callback to be passed the result (of arbitrary type) of the first work item. The callback is posted to the originating WorkQueue, permitting safe data exchange between participating threads. Methods are provided for different kinds of servicing threads. runUntilClose() is useful for a simple worker thread. runFor(duration) devotes no more than a specified time slice to that WorkQueue, e.g. for use by the main thread.