rte_spinlock.h

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/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2014 Intel Corporation
 */

#ifndef _RTE_SPINLOCK_H_
#define _RTE_SPINLOCK_H_

#include <rte_lcore.h>
#ifdef RTE_FORCE_INTRINSICS
#include <rte_common.h>
#endif
#include <rte_debug.h>
#include <rte_lock_annotations.h>
#include <rte_pause.h>
#include <rte_stdatomic.h>

#ifdef __cplusplus
extern "C" {
#endif

typedef struct __rte_capability("spinlock") {
    volatile RTE_ATOMIC(int) locked; 
} rte_spinlock_t;

#define RTE_SPINLOCK_INITIALIZER { 0 }

static inline void
rte_spinlock_init(rte_spinlock_t *sl)
{
    sl->locked = 0;
}

static inline void
rte_spinlock_lock(rte_spinlock_t *sl)
    __rte_acquire_capability(sl);

#ifdef RTE_FORCE_INTRINSICS
static inline void
rte_spinlock_lock(rte_spinlock_t *sl)
    __rte_no_thread_safety_analysis
{
    int exp = 0;

    while (!rte_atomic_compare_exchange_strong_explicit(&sl->locked, &exp, 1,
                rte_memory_order_acquire, rte_memory_order_relaxed)) {
        rte_wait_until_equal_32((volatile uint32_t *)(uintptr_t)&sl->locked,
                   0, rte_memory_order_relaxed);
        exp = 0;
    }
}
#endif

static inline void
rte_spinlock_unlock(rte_spinlock_t *sl)
    __rte_release_capability(sl);

#ifdef RTE_FORCE_INTRINSICS
static inline void
rte_spinlock_unlock(rte_spinlock_t *sl)
    __rte_no_thread_safety_analysis
{
    rte_atomic_store_explicit(&sl->locked, 0, rte_memory_order_release);
}
#endif

__rte_warn_unused_result
static inline int
rte_spinlock_trylock(rte_spinlock_t *sl)
    __rte_try_acquire_capability(true, sl);

#ifdef RTE_FORCE_INTRINSICS
static inline int
rte_spinlock_trylock(rte_spinlock_t *sl)
    __rte_no_thread_safety_analysis
{
    int exp = 0;
    return rte_atomic_compare_exchange_strong_explicit(&sl->locked, &exp, 1,
                rte_memory_order_acquire, rte_memory_order_relaxed);
}
#endif

static inline int rte_spinlock_is_locked (rte_spinlock_t *sl)
{
    return rte_atomic_load_explicit(&sl->locked, rte_memory_order_acquire);
}

static inline int rte_tm_supported(void);

static inline void
rte_spinlock_lock_tm(rte_spinlock_t *sl)
    __rte_acquire_capability(sl);

static inline void
rte_spinlock_unlock_tm(rte_spinlock_t *sl)
    __rte_release_capability(sl);

__rte_warn_unused_result
static inline int
rte_spinlock_trylock_tm(rte_spinlock_t *sl)
    __rte_try_acquire_capability(true, sl);

typedef struct {
    rte_spinlock_t sl; 
    RTE_ATOMIC(int) owner; 
    int count; 
} rte_spinlock_recursive_t;

#define RTE_SPINLOCK_RECURSIVE_INITIALIZER {RTE_SPINLOCK_INITIALIZER, -1, 0}

static inline void rte_spinlock_recursive_init(rte_spinlock_recursive_t *slr)
{
    rte_spinlock_init(&slr->sl);
    rte_atomic_store_explicit(&slr->owner, -1, rte_memory_order_relaxed);
    slr->count = 0;
}

static inline void rte_spinlock_recursive_lock(rte_spinlock_recursive_t *slr)
    __rte_no_thread_safety_analysis
{
    int id = rte_gettid();

    if (rte_atomic_load_explicit(&slr->owner, rte_memory_order_relaxed) != id) {
        rte_spinlock_lock(&slr->sl);
        rte_atomic_store_explicit(&slr->owner, id, rte_memory_order_relaxed);
    }
    slr->count++;
}
static inline void rte_spinlock_recursive_unlock(rte_spinlock_recursive_t *slr)
    __rte_no_thread_safety_analysis
{
    RTE_ASSERT(rte_atomic_load_explicit(&slr->owner, rte_memory_order_relaxed) == rte_gettid());
    RTE_ASSERT(slr->count > 0);
    if (--(slr->count) == 0) {
        rte_atomic_store_explicit(&slr->owner, -1, rte_memory_order_relaxed);
        rte_spinlock_unlock(&slr->sl);
    }
}

__rte_warn_unused_result
static inline int rte_spinlock_recursive_trylock(rte_spinlock_recursive_t *slr)
    __rte_no_thread_safety_analysis
{
    int id = rte_gettid();

    if (rte_atomic_load_explicit(&slr->owner, rte_memory_order_relaxed) != id) {
        if (rte_spinlock_trylock(&slr->sl) == 0)
            return 0;
        rte_atomic_store_explicit(&slr->owner, id, rte_memory_order_relaxed);
    }
    slr->count++;
    return 1;
}


static inline void rte_spinlock_recursive_lock_tm(
    rte_spinlock_recursive_t *slr);

static inline void rte_spinlock_recursive_unlock_tm(
    rte_spinlock_recursive_t *slr);

__rte_warn_unused_result
static inline int rte_spinlock_recursive_trylock_tm(
    rte_spinlock_recursive_t *slr);

#ifdef __cplusplus
}
#endif

#endif /* _RTE_SPINLOCK_H_ */