/* SPDX-FileCopyrightText: 2006 Blender Authors
 *
 * SPDX-License-Identifier: GPL-2.0-or-later */

#pragma once

/** \file
 * \ingroup bli
 */

#include <pthread.h>

#include "BLI_listbase.h"
#include "BLI_sys_types.h"

namespace blender {

/** For tables, button in UI, etc. */
#define BLENDER_MAX_THREADS 1024

struct ThreadSlot;

/* Threading API */

/**
 * This is run once at startup.
 */
void BLI_threadapi_init();
void BLI_threadapi_exit();

/**
 * \param tot: When 0 only initializes `malloc` mutex in a safe way (see sequence.c)
 * problem otherwise: scene render will kill of the mutex!
 */
void BLI_threadpool_init(ListBaseT<ThreadSlot> *threadbase, void *(*do_thread)(void *), int tot);
/**
 * Amount of available threads.
 */
int BLI_available_threads(ListBaseT<ThreadSlot> *threadbase);
/**
 * Returns thread number, for sample patterns or threadsafe tables.
 */
int BLI_threadpool_available_thread_index(ListBaseT<ThreadSlot> *threadbase);
void BLI_threadpool_insert(ListBaseT<ThreadSlot> *threadbase, void *callerdata);
void BLI_threadpool_remove(ListBaseT<ThreadSlot> *threadbase, void *callerdata);
void BLI_threadpool_remove_index(ListBaseT<ThreadSlot> *threadbase, int index);
void BLI_threadpool_clear(ListBaseT<ThreadSlot> *threadbase);
void BLI_threadpool_end(ListBaseT<ThreadSlot> *threadbase);
int BLI_thread_is_main();

/* System Information */

/**
 * \return the number of threads the system can make use of.
 */
int BLI_system_thread_count();
void BLI_system_num_threads_override_set(int num);
int BLI_system_num_threads_override_get();

/**
 * Global Mutex Locks
 *
 * One custom lock available now. can be extended.
 */
enum {
  LOCK_IMAGE = 0,
  LOCK_DRAW_IMAGE,
  LOCK_VIEWER,
  LOCK_CUSTOM1,
  LOCK_NODES,
  LOCK_MOVIECLIP,
  LOCK_FFTW,
  LOCK_VIEW3D,
};

void BLI_thread_lock(int type);
void BLI_thread_unlock(int type);

/* Mutex Lock */

typedef pthread_mutex_t ThreadMutex;
#define BLI_MUTEX_INITIALIZER PTHREAD_MUTEX_INITIALIZER

void BLI_mutex_init(ThreadMutex *mutex);
void BLI_mutex_end(ThreadMutex *mutex);

ThreadMutex *BLI_mutex_alloc();
void BLI_mutex_free(ThreadMutex *mutex);

void BLI_mutex_lock(ThreadMutex *mutex);
bool BLI_mutex_trylock(ThreadMutex *mutex);
void BLI_mutex_unlock(ThreadMutex *mutex);

/* Spin Lock */

/* By default we use TBB for spin lock on all platforms. When building without
 * TBB fall-back to spin lock implementation which is native to the platform.
 *
 * On macOS we use mutex lock instead of spin since the spin lock has been
 * deprecated in SDK 10.12 and is discouraged from use. */

#ifdef WITH_TBB
typedef uint32_t SpinLock;
#elif defined(__APPLE__)
typedef ThreadMutex SpinLock;
#elif defined(_MSC_VER)
typedef volatile unsigned int SpinLock;
#else
typedef pthread_spinlock_t SpinLock;
#endif

void BLI_spin_init(SpinLock *spin);
void BLI_spin_lock(SpinLock *spin);
void BLI_spin_unlock(SpinLock *spin);
void BLI_spin_end(SpinLock *spin);

/* Read/Write Mutex Lock */

#define THREAD_LOCK_READ 1
#define THREAD_LOCK_WRITE 2

#define BLI_RWLOCK_INITIALIZER PTHREAD_RWLOCK_INITIALIZER

typedef pthread_rwlock_t ThreadRWMutex;

void BLI_rw_mutex_init(ThreadRWMutex *mutex);
void BLI_rw_mutex_end(ThreadRWMutex *mutex);

ThreadRWMutex *BLI_rw_mutex_alloc();
void BLI_rw_mutex_free(ThreadRWMutex *mutex);

void BLI_rw_mutex_lock(ThreadRWMutex *mutex, int mode);
void BLI_rw_mutex_unlock(ThreadRWMutex *mutex);

/* Ticket Mutex Lock
 *
 * This is a 'fair' mutex in that it will grant the lock to the first thread
 * that requests it. */

struct TicketMutex;

TicketMutex *BLI_ticket_mutex_alloc();
void BLI_ticket_mutex_free(TicketMutex *ticket);
void BLI_ticket_mutex_lock(TicketMutex *ticket);
bool BLI_ticket_mutex_lock_check_recursive(TicketMutex *ticket);
void BLI_ticket_mutex_unlock(TicketMutex *ticket);

/* Condition */

typedef pthread_cond_t ThreadCondition;

void BLI_condition_init(ThreadCondition *cond);
void BLI_condition_wait(ThreadCondition *cond, ThreadMutex *mutex);
void BLI_condition_wait_global_mutex(ThreadCondition *cond, int type);
void BLI_condition_notify_one(ThreadCondition *cond);
void BLI_condition_notify_all(ThreadCondition *cond);
void BLI_condition_end(ThreadCondition *cond);

/* ThreadWorkQueue
 *
 * Thread-safe work queue to push work/pointers between threads. */

struct ThreadQueue;

enum ThreadQueueWorkPriority {
  BLI_THREAD_QUEUE_WORK_PRIORITY_LOW,
  BLI_THREAD_QUEUE_WORK_PRIORITY_NORMAL,
  BLI_THREAD_QUEUE_WORK_PRIORITY_HIGH,
};

/**
 * Allocate a new ThreadQueue.
 */
ThreadQueue *BLI_thread_queue_init();

/**
 * Deallocate the ThreadQueue.
 * Assumes no one is using the queue anymore.
 */
void BLI_thread_queue_free(ThreadQueue *queue);

/**
 * Push one work pointer to the queue.
 * Higher priority works always take priority over lower priority ones, regardless of their
 * insertion order. Works within the same priority follow FIFO order.
 *
 * \returns a unique work_id that can be used later for canceling the work before it's popped out
 * from the queue.
 */
uint64_t BLI_thread_queue_push(ThreadQueue *queue, void *work, ThreadQueueWorkPriority priority);

/**
 * Remove the corresponding work from the queue.
 *
 * \returns true if the work_id was still in the queue.
 */
bool BLI_thread_queue_cancel_work(ThreadQueue *queue, uint64_t work_id);

/**
 * Pop the oldest, highest priority work from the queue.
 * Blocks the calling thread unless BLI_thread_queue_nowait has been called for this queue.
 *
 * \returns nullptr if nowait has been set and the queue is empty. Otherwise returns a work
 * pointer.
 */
void *BLI_thread_queue_pop(ThreadQueue *queue);

/**
 * Try to pop the oldest, highest priority work from the queue.
 * Blocks the calling thread unless BLI_thread_queue_nowait has been called for this queue.
 *
 * \returns nullptr if time runs out, or if nowait has been set and the queue is empty. Otherwise
 * returns a work pointer.
 */
void *BLI_thread_queue_pop_timeout(ThreadQueue *queue, int ms);

/**
 * \returns the total amount of pending works still in the queue.
 */
int BLI_thread_queue_len(ThreadQueue *queue);

/**
 * \returns true if there are no pending works in the queue.
 */
bool BLI_thread_queue_is_empty(ThreadQueue *queue);

/**
 * Blocks the calling thread until the queue is empty.
 */
void BLI_thread_queue_wait_finish(ThreadQueue *queue);

/**
 * After calling this function, BLI_thread_queue_pop and BLI_thread_queue_pop_timeout won't block
 * the calling thread even when the queue is empty.
 */
void BLI_thread_queue_nowait(ThreadQueue *queue);

/* Thread local storage */

#if defined(__APPLE__)
#  define ThreadLocal(type) pthread_key_t
#  define BLI_thread_local_create(name) pthread_key_create(&name, NULL)
#  define BLI_thread_local_delete(name) pthread_key_delete(name)
#  define BLI_thread_local_get(name) pthread_getspecific(name)
#  define BLI_thread_local_set(name, value) pthread_setspecific(name, value)
#else /* defined(__APPLE__) */
#  ifdef _MSC_VER
#    define ThreadLocal(type) __declspec(thread) type
#  else
#    define ThreadLocal(type) __thread type
#  endif
#  define BLI_thread_local_create(name)
#  define BLI_thread_local_delete(name)
#  define BLI_thread_local_get(name) name
#  define BLI_thread_local_set(name, value) name = value
#endif /* defined(__APPLE__) */

}  // namespace blender