experimental/cuda2/event_semaphore.h

// Copyright 2023 The IREE Authors
//
// Licensed under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

#ifndef EXPERIMENTAL_CUDA2_EVENT_SEMAPHORE_H_
#define EXPERIMENTAL_CUDA2_EVENT_SEMAPHORE_H_

#include <stdint.h>

#include "experimental/cuda2/cuda_dynamic_symbols.h"
#include "experimental/cuda2/pending_queue_actions.h"
#include "experimental/cuda2/timepoint_pool.h"
#include "iree/base/api.h"
#include "iree/hal/api.h"

#ifdef __cplusplus
extern "C" {
#endif  // __cplusplus

// Creates an IREE HAL semaphore with the given |initial_value|.
//
// The HAL semaphore are backed by iree_event_t or CUevent objects for different
// timepoints along the timeline under the hood. Those timepoints will be
// allocated from the |timepoint_pool|.
//
// This semaphore is meant to be used together with a pending queue actions; it
// may advance the given |pending_queue_actions| if new values are signaled.
//
// Thread-safe; multiple threads may signal/wait values on the same semaphore.
iree_status_t iree_hal_cuda2_event_semaphore_create(
    uint64_t initial_value, const iree_hal_cuda2_dynamic_symbols_t* symbols,
    iree_hal_cuda2_timepoint_pool_t* timepoint_pool,
    iree_hal_cuda2_pending_queue_actions_t* pending_queue_actions,
    iree_allocator_t host_allocator, iree_hal_semaphore_t** out_semaphore);

// Acquires a timepoint to signal the timeline to the given |to_value| from the
// device. The underlying CUDA event is written into |out_event| for interacting
// with CUDA APIs.
iree_status_t iree_hal_cuda2_event_semaphore_acquire_timepoint_device_signal(
    iree_hal_semaphore_t* base_semaphore, uint64_t to_value,
    CUevent* out_event);

// Acquires a timepoint to wait the timeline to reach at least the given
// |min_value| on the device The underlying CUDA event is written into
// |out_event| for interacting with CUDA APIs.
iree_status_t iree_hal_cuda2_event_semaphore_acquire_timepoint_device_wait(
    iree_hal_semaphore_t* base_semaphore, uint64_t min_value,
    CUevent* out_event);

#ifdef __cplusplus
}  // extern "C"
#endif  // __cplusplus

#endif  // EXPERIMENTAL_CUDA2_EVENT_SEMAPHORE_H_