Brecht Van Lommel
fcc844f8fb
After looking into task isolation issues with Sergey, we couldn't find the reason behind the deadlocks that we are getting in T87938 and a Sprite Fright file involving motion blur renders. There is no apparent place where we adding or waiting on tasks in a task group from different isolation regions, which is what is known to cause problems. Yet it still hangs. Either we do not understand some limitation of TBB isolation, or there is a bug in TBB, but we could not figure it out. Instead the idea is to use isolation only where we know we need it: when holding a mutex lock and then doing some multithreaded operation within that locked region. Three places where we do this now: * Generated images * Cached BVH tree building * OpenVDB lazy grid loading Compared to the more automatic approach previously used, there is the downside that it is easy to miss places where we need isolation. Yet doing it more automatically is also causing unexpected issue and bugs that we found no solution for, so this seems better. Patch implemented by Sergey and me. Differential Revision: https://developer.blender.org/D11603
89 lines
2.6 KiB
C++
89 lines
2.6 KiB
C++
/*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*/
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/** \file
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* \ingroup bli
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*
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* Task scheduler initialization.
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*/
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#include "MEM_guardedalloc.h"
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#include "BLI_task.h"
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#include "BLI_threads.h"
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#ifdef WITH_TBB
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/* Need to include at least one header to get the version define. */
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# include <tbb/blocked_range.h>
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# include <tbb/task_arena.h>
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# if TBB_INTERFACE_VERSION_MAJOR >= 10
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# include <tbb/global_control.h>
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# define WITH_TBB_GLOBAL_CONTROL
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# endif
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#endif
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/* Task Scheduler */
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static int task_scheduler_num_threads = 1;
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#ifdef WITH_TBB_GLOBAL_CONTROL
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static tbb::global_control *task_scheduler_global_control = nullptr;
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#endif
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void BLI_task_scheduler_init()
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{
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#ifdef WITH_TBB_GLOBAL_CONTROL
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const int num_threads_override = BLI_system_num_threads_override_get();
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if (num_threads_override > 0) {
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/* Override number of threads. This settings is used within the lifetime
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* of tbb::global_control, so we allocate it on the heap. */
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task_scheduler_global_control = OBJECT_GUARDED_NEW(
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tbb::global_control, tbb::global_control::max_allowed_parallelism, num_threads_override);
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task_scheduler_num_threads = num_threads_override;
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}
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else {
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/* Let TBB choose the number of threads. For (legacy) code that calls
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* BLI_task_scheduler_num_threads() we provide the system thread count.
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* Ideally such code should be rewritten not to use the number of threads
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* at all. */
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task_scheduler_num_threads = BLI_system_thread_count();
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}
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#else
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task_scheduler_num_threads = BLI_system_thread_count();
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#endif
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}
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void BLI_task_scheduler_exit()
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{
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#ifdef WITH_TBB_GLOBAL_CONTROL
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OBJECT_GUARDED_DELETE(task_scheduler_global_control, tbb::global_control);
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#endif
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}
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int BLI_task_scheduler_num_threads()
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{
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return task_scheduler_num_threads;
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}
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void BLI_task_isolate(void (*func)(void *userdata), void *userdata)
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{
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#ifdef WITH_TBB
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tbb::this_task_arena::isolate([&] { func(userdata); });
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#else
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func(userdata);
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#endif
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}
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