8.2.13 _gfortran_caf_sendget — Sending data between remote images

Description:

Called to send a scalar, an array section or a whole array from a remote image identified by the src_image_index to a remote image identified by the dst_image_index.

Syntax:

void _gfortran_caf_sendget (caf_token_t dst_token, size_t dst_offset, int dst_image_index, gfc_descriptor_t *dest, caf_vector_t *dst_vector, caf_token_t src_token, size_t src_offset, int src_image_index, gfc_descriptor_t *src, caf_vector_t *src_vector, int dst_kind, int src_kind, bool may_require_tmp, int *stat)

Arguments:

dst_token	intent(in) An opaque pointer identifying the destination coarray.
dst_offset	intent(in) By which amount of bytes the actual data is shifted compared to the base address of the destination coarray.
dst_image_index	intent(in) The ID of the destination remote image; must be a positive number.
dest	intent(in) Array descriptor for the destination remote image for the bounds and the size. The base_addr shall not be accessed.
dst_vector	intent(int) If not NULL, it contains the vector subscript of the destination array; the values are relative to the dimension triplet of the dest argument.
src_token	intent(in) An opaque pointer identifying the source coarray.
src_offset	intent(in) By which amount of bytes the actual data is shifted compared to the base address of the source coarray.
src_image_index	intent(in) The ID of the source remote image; must be a positive number.
src	intent(in) Array descriptor of the local array to be transferred to the remote image.
src_vector	intent(in) Array descriptor of the local array to be transferred to the remote image
dst_kind	intent(in) Kind of the destination argument
src_kind	intent(in) Kind of the source argument
may_require_tmp	intent(in) The variable is false when it is known at compile time that the dest and src either cannot overlap or overlap (fully or partially) such that walking src and dest in element wise element order (honoring the stride value) will not lead to wrong results. Otherwise, the value is true.
stat	intent(out) when non-NULL give the result of the operation, i.e., zero on success and non-zero on error. When NULL and an error occurs, then an error message is printed and the program is terminated.

NOTES

It is permitted to have the same image index for both src_image_index and dst_image_index; the memory of the send-to and the send-from might (partially) overlap in that case. The implementation has to take care that it handles this case, e.g. using memmove which handles (partially) overlapping memory. If may_require_tmp is true, the library might additionally create a temporary variable, unless additional checks show that this is not required (e.g. because walking backward is possible or because both arrays are contiguous and memmove takes care of overlap issues).

Note that the assignment of a scalar to an array is permitted. In addition, the library has to handle numeric-type conversion and for strings, padding and different character kinds.