/*
 * Copyright © Microsoft Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#include "d3d12_fence.h"

#include "d3d12_context.h"
#include "d3d12_screen.h"

#include "util/u_memory.h"

#include <dxguids/dxguids.h>

constexpr uint64_t NsPerMs = 1000000;
constexpr uint64_t MaxTimeoutInNs = (uint64_t)UINT_MAX * NsPerMs;

#ifdef _WIN32
static void
close_event(HANDLE event, int fd)
{
   if (event)
      CloseHandle(event);
}

static HANDLE
create_event(int *fd)
{
   *fd = -1;
   return CreateEvent(NULL, FALSE, FALSE, NULL);
}

static bool
wait_event(HANDLE event, int event_fd, uint64_t timeout_ns)
{
   DWORD timeout_ms = (timeout_ns == PIPE_TIMEOUT_INFINITE || timeout_ns > MaxTimeoutInNs) ? INFINITE : timeout_ns / NsPerMs;
   return WaitForSingleObject(event, timeout_ms) == WAIT_OBJECT_0;
}
#else
#include <sys/eventfd.h>
#include <poll.h>
#include <util/libsync.h>

static void
close_event(HANDLE event, int fd)
{
   if (fd != -1)
      close(fd);
}

static HANDLE
create_event(int *fd)
{
   *fd = eventfd(0, 0);
   return (HANDLE)(size_t)*fd;
}

static bool
wait_event(HANDLE event, int event_fd, uint64_t timeout_ns)
{
   int timeout_ms = (timeout_ns == PIPE_TIMEOUT_INFINITE || timeout_ns > MaxTimeoutInNs) ? -1 : timeout_ns / NsPerMs;
   return sync_wait(event_fd, timeout_ms) == 0;
}
#endif

static void
destroy_fence(struct d3d12_fence *fence)
{
   close_event(fence->event, fence->event_fd);
   FREE(fence);
}

struct d3d12_fence *
d3d12_create_fence(struct d3d12_screen *screen)
{
   struct d3d12_fence *ret = CALLOC_STRUCT(d3d12_fence);
   if (!ret) {
      debug_printf("CALLOC_STRUCT failed\n");
      return NULL;
   }

   ret->cmdqueue_fence = screen->fence;
   ret->value = ++screen->fence_value;
   ret->event = create_event(&ret->event_fd);
   if (FAILED(screen->fence->SetEventOnCompletion(ret->value, ret->event)))
      goto fail;
   if (FAILED(screen->cmdqueue->Signal(screen->fence, ret->value)))
      goto fail;

   pipe_reference_init(&ret->reference, 1);
   return ret;

fail:
   destroy_fence(ret);
   return NULL;
}

struct d3d12_fence *
d3d12_open_fence(struct d3d12_screen *screen, HANDLE handle, const void *name)
{
   struct d3d12_fence *ret = CALLOC_STRUCT(d3d12_fence);
   if (!ret) {
      debug_printf("CALLOC_STRUCT failed\n");
      return NULL;
   }

   HANDLE handle_to_close = nullptr;
   assert(!!handle ^ !!name);
   if (name) {
      screen->dev->OpenSharedHandleByName((LPCWSTR)name, GENERIC_ALL, &handle_to_close);
      handle = handle_to_close;
   }

   screen->dev->OpenSharedHandle(handle, IID_PPV_ARGS(&ret->cmdqueue_fence));
   if (!ret->cmdqueue_fence) {
      free(ret);
      return NULL;
   }

   /* A new value will be assigned later */
   ret->value = 0;
   pipe_reference_init(&ret->reference, 1);
   return ret;
}

void
d3d12_fence_reference(struct d3d12_fence **ptr, struct d3d12_fence *fence)
{
   if (pipe_reference(&(*ptr)->reference, &fence->reference))
      destroy_fence((struct d3d12_fence *)*ptr);

   *ptr = fence;
}

static void
fence_reference(struct pipe_screen *pscreen,
                struct pipe_fence_handle **pptr,
                struct pipe_fence_handle *pfence)
{
   d3d12_fence_reference((struct d3d12_fence **)pptr, d3d12_fence(pfence));
}

bool
d3d12_fence_finish(struct d3d12_fence *fence, uint64_t timeout_ns)
{
   if (fence->signaled)
      return true;
   
   bool complete = fence->cmdqueue_fence->GetCompletedValue() >= fence->value;
   if (!complete && timeout_ns)
      complete = wait_event(fence->event, fence->event_fd, timeout_ns);

   fence->signaled = complete;
   return complete;
}

static bool
fence_finish(struct pipe_screen *pscreen, struct pipe_context *pctx,
             struct pipe_fence_handle *pfence, uint64_t timeout_ns)
{
   bool ret = d3d12_fence_finish(d3d12_fence(pfence), timeout_ns);
   if (ret && pctx) {
      pctx = threaded_context_unwrap_sync(pctx);
      struct d3d12_context *ctx = d3d12_context(pctx);
      d3d12_foreach_submitted_batch(ctx, batch)
         d3d12_reset_batch(ctx, batch, 0);
   }
   return ret;
}

void
d3d12_screen_fence_init(struct pipe_screen *pscreen)
{
   pscreen->fence_reference = fence_reference;
   pscreen->fence_finish = fence_finish;
}