The open source OpenXR runtime
u/worker: Split tracking of waiting tasks and in progress tasks
Without this the code could deadlock on wait_all because the count
would get out of sync when pushing more tasks then threads without
waiting on the work.
Part-of: <https://gitlab.freedesktop.org/monado/monado/-/merge_requests/2619>
authored by
Jakob Bornecrantz
and committed by
Marge Bot
325bcbe6
acd3d464
+25
-7
+25
-7
src/xrt/auxiliary/util/u_worker.c
+25
-7
src/xrt/auxiliary/util/u_worker.c
···
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//! Pointer to poll of threads.
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struct u_worker_thread_pool *uwtp;
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//! Number of tasks that is pending or being worked on in this group.
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size_t current_submitted_tasks_count;
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/*!
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* The number of tasks that are pending execution by a worker.
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* They reside in the pool::tasks array.
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*/
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uint32_t current_tasks_in_array;
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/*!
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* Number of tasks that are being worked on.
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* They live inside of the working thread.
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*/
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uint32_t current_working_tasks;
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/*!
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* Number of waiting threads that have been released by a worker,
···
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continue;
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}
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*out_task = p->tasks[i];
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struct task task = p->tasks[i];
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p->tasks[i] = (struct task){NULL, NULL, NULL};
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p->tasks_in_array_count--;
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task.g->current_tasks_in_array--;
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task.g->current_working_tasks++;
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*out_task = task;
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return;
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}
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···
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p->tasks[i] = (struct task){g, func, data};
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p->tasks_in_array_count++;
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g->current_submitted_tasks_count++;
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g->current_tasks_in_array++;
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return;
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}
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···
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static bool
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locked_group_has_tasks_waiting_or_inflight(const struct group *g)
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{
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if (g->current_submitted_tasks_count == 0) {
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if (g->current_tasks_in_array == 0 && g->current_working_tasks == 0) {
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return false;
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}
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···
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// No longer working.
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p->working_count--;
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// Only now decrement the task count on the owning group.
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task.g->current_submitted_tasks_count--;
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// We are no longer working on the task.
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task.g->current_working_tasks--;
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// This must hold true.
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assert(task.g->current_tasks_in_array <= p->tasks_in_array_count);
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// Wake up any waiter.
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locked_group_wake_waiter_if_allowed(p, task.g);