50 lines
1022 B
C
50 lines
1022 B
C
/*
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* Copyright (c) 2017, Linaro Limited. and Contributors. All rights reserved.
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*
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* SPDX-License-Identifier: BSD-3-Clause
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*/
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/*
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* @file zephyr/condition.c
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* @brief Zephyr libmetal condition variable handling.
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*/
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#include <metal/condition.h>
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#include <metal/irq.h>
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extern void metal_generic_default_poll(void);
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int metal_condition_wait(struct metal_condition *cv,
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metal_mutex_t *m)
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{
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metal_mutex_t *tmpm = 0;
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int v;
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unsigned int flags;
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/* Check if the mutex has been acquired */
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if (!cv || !m || !metal_mutex_is_acquired(m))
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return -EINVAL;
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if (!atomic_compare_exchange_strong(&cv->m, &tmpm, m)) {
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if (m != tmpm)
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return -EINVAL;
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}
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v = atomic_load(&cv->v);
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/* Release the mutex first. */
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metal_mutex_release(m);
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do {
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flags = metal_irq_save_disable();
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if (atomic_load(&cv->v) != v) {
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metal_irq_restore_enable(flags);
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break;
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}
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metal_generic_default_poll();
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metal_irq_restore_enable(flags);
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} while(1);
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/* Acquire the mutex again. */
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metal_mutex_acquire(m);
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return 0;
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}
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