60 lines
2.1 KiB
C
60 lines
2.1 KiB
C
/*
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* Copyright 2020 Hans-Kristian Arntzen for Valve Corporation
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library 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 GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
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*/
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#ifndef __VKD3D_RW_SPINLOCK_H
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#define __VKD3D_RW_SPINLOCK_H
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#include "vkd3d_spinlock.h"
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#define VKD3D_RW_SPINLOCK_WRITE 1u
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#define VKD3D_RW_SPINLOCK_READ 2u
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#define VKD3D_RW_SPINLOCK_IDLE 0u
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static inline void rw_spinlock_acquire_read(spinlock_t *spinlock)
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{
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uint32_t count = vkd3d_atomic_uint32_add(spinlock, VKD3D_RW_SPINLOCK_READ, vkd3d_memory_order_acquire);
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while (count & VKD3D_RW_SPINLOCK_WRITE)
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{
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vkd3d_pause();
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count = vkd3d_atomic_uint32_load_explicit(spinlock, vkd3d_memory_order_acquire);
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}
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}
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static inline void rw_spinlock_release_read(spinlock_t *spinlock)
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{
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vkd3d_atomic_uint32_sub(spinlock, VKD3D_RW_SPINLOCK_READ, vkd3d_memory_order_release);
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}
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static inline void rw_spinlock_acquire_write(spinlock_t *spinlock)
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{
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while (vkd3d_atomic_uint32_load_explicit(spinlock, vkd3d_memory_order_relaxed) != VKD3D_RW_SPINLOCK_IDLE ||
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vkd3d_atomic_uint32_compare_exchange(spinlock,
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VKD3D_RW_SPINLOCK_IDLE, VKD3D_RW_SPINLOCK_WRITE,
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vkd3d_memory_order_acquire, vkd3d_memory_order_relaxed) != VKD3D_RW_SPINLOCK_IDLE)
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{
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vkd3d_pause();
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}
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}
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static inline void rw_spinlock_release_write(spinlock_t *spinlock)
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{
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vkd3d_atomic_uint32_and(spinlock, ~VKD3D_RW_SPINLOCK_WRITE, vkd3d_memory_order_release);
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}
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#endif
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