omp_target_memcpy_async (GNU libgomp)

#### 3.8.6 `omp_target_memcpy_async` – Copy data between devices asynchronously ¶

Description:

  This routine copies asynchronously length of bytes of data from the device identified by device number src_device_num to device dst_device_num. The data is copied from the source device from the address provided by src, shifted by the offset of src_offset bytes, to the destination device’s dst address shifted by dst_offset. Task dependence is expressed by passing an array of depend objects to depobj_list, where the number of array elements is passed as depobj_count; if the count is zero, the depobj_list argument is ignored. In C++ and Fortran, the depobj_list argument can also be omitted in that case. The routine returns zero if the copying process has successfully been started and non-zero otherwise.

  Running this routine in a `target` region except on the initial device is not supported.

C/C++

  Prototype: | `int omp_target_memcpy_async(void *dst,`
  | `const void *src,`
  | `size_t length,`
  | `size_t dst_offset,`
  | `size_t src_offset,`
  | `int dst_device_num,`
  | `int src_device_num,`
  | `int depobj_count,`
  | `omp_depend_t *depobj_list)`

Fortran:

  Interface: | `integer(c_int) function omp_target_memcpy_async( &`
  | `dst, src, length, dst_offset, src_offset, &`
  | `dst_device_num, src_device_num, &`
  | `depobj_count, depobj_list) bind(C)`
  | `use, intrinsic :: iso_c_binding, only: c_ptr, c_size_t, c_int`
  | `type(c_ptr), value :: dst, src`
  | `integer(c_size_t), value :: length, dst_offset, src_offset`
  | `integer(c_int), value :: dst_device_num, src_device_num, depobj_count`
  | `integer(omp_depend_kind), optional :: depobj_list(*)`

See also:

  `omp_target_memcpy` – Copy data between devices, `omp_target_memcpy_rect_async` – Copy a subvolume of data between devices asynchronously

Reference:

  OpenMP specification v5.1, Section 3.8.7