# Implementation Status

Caffeine is an implementation of the Parallel Runtime Interface for Fortran (PRIF). This document
outlines the implementation status in Caffeine of the features defined in the
[latest PRIF specification, revision 0.7](https://doi.org/10.25344/S46S3W). Caffeine contains interfaces for all
of the PRIF procedures (except when stated otherwise below) and the symbols are linkable and callable, but some procedures will fail at runtime with an unimplemented error. For
more details about the implementation of the various PRIF features, please see the
following sections:

- [Named Constants](#Named-Constants)
- [Program Startup and Shutdown](#Program-Startup-and-Shutdown)
- [Image Queries](#Image-Queries)
- [Storage Management](#Storage-Management)
- [Coarray Queries](#Coarray-Queries)
- [Contiguous Coarray Access](#Contiguous-Coarray-Access)
- [Strided Coarray Access](#Strided-Coarray-Access)
- [SYNC Statements](#SYNC-Statements)
- [Locks and Unlocks](#Locks-and-Unlocks)
- [Critical](#Critical)
- [Events and Notifications](#Events-and-Notifications)
- [Teams](#teams)
- [Collectives](#Collectives)
- [Atomic Memory Operations](#Atomic-Memory-Operations)

The priorites for feature implementation and addressing known defects are communicated by
the labels in the Caffeine [issue tracker](https://github.com/BerkeleyLab/caffeine/issues).

## Named Constants

Caffeine contains definitions for all of the PRIF-relevant constants from `ISO_FORTRAN_ENV` and for
all of the PRIF-specific constants.
Configuration settings (`CAF_IMPORT_*` preprocessor defines) can optionally be used to import
selected constant values from `ISO_FORTRAN_ENV` of the hosting compiler.

## Program Startup and Shutdown

| Procedure | Status | Notes |
|-----------|--------|-------|
| `prif_init` | **YES** |  |
| `prif_stop`, `prif_error_stop` | **YES** |  |
| `prif_fail_image` | **YES** | trivial implementation |
| `prif_register_stop_callback` | **YES** |  |


---

## Image Queries

| Procedure | Status | Notes |
|-----------|--------|-------|
| `prif_num_images`                   | **YES** |  |
| `prif_num_images_with_team`         | **YES** |  |
| `prif_num_images_with_team_number`  | *partial* | no support for sibling teams |
| `prif_this_image_no_coarray`        | **YES** |  |
| `prif_this_image_with_coarray`, `prif_this_image_with_dim`  | **YES** |  |
| `prif_failed_images`                | **YES** |  |
| `prif_stopped_images`               | **YES** |  |
| `prif_image_status`                 | **YES** |  |

---

## Storage Management

| Procedure | Status | Notes |
|-----------|--------|-------|
| `prif_allocate_coarray`    | **YES** | includes ucobound relaxation expected in PRIF 0.8 |
| `prif_allocate`            | **YES** |  |
| `prif_deallocate_coarray`  | **YES** | `final_func` support requires flang 20+ |
| `prif_deallocate_coarrays` | **YES** | `final_func` support requires flang 20+ |
| `prif_deallocate`          | **YES** |  |
| `prif_alias_create`        | **YES** | includes ucobound relaxation expected in PRIF 0.8 |
| `prif_alias_destroy`       | **YES** |  |

---

## Coarray Queries

| Procedure | Status | Notes |
|-----------|--------|-------|
| `prif_set_context_data`, `prif_get_context_data` | **YES** |  |
| `prif_size_bytes`                                | **YES** |  |
| `prif_lcobound_no_dim`, `prif_lcobound_with_dim` | **YES** |  |
| `prif_ucobound_no_dim`, `prif_ucobound_with_dim` | **YES** |  |
| `prif_coshape`                                   | **YES** |  |
| `prif_local_data_pointer`                        | **YES** |  |
| `prif_image_index`                               | **YES** |  |
| `prif_image_index_with_team`                     | **YES** |  |
| `prif_image_index_with_team_number`              | *partial* | no support for sibling teams |
| `prif_initial_team_index`                        | **YES** | |
| `prif_initial_team_index_with_team`              | **YES** | |
| `prif_initial_team_index_with_team_number`       | *partial* | no support for sibling teams |

---

## Contiguous Coarray Access

| Procedure | Status | Notes |
|-----------|--------|-------|
| `prif_get`                               | **YES** |  |
| `prif_get_indirect`                      | **YES** |  |
| `prif_put`                               | **YES** |  |
| `prif_put_indirect`                      | **YES** |  |
| `prif_put_with_notify`                   | **YES** |  |
| `prif_put_with_notify_indirect`          | **YES** |  |
| `prif_put_indirect_with_notify`          | **YES** |  |
| `prif_put_indirect_with_notify_indirect` | **YES** |  |

---

## Strided Coarray Access

| Procedure | Status | Notes |
|-----------|--------|-------|
| `prif_get_strided`                               | **YES** |  |
| `prif_get_strided_indirect`                      | **YES** |  |
| `prif_put_strided`                               | **YES** |  |
| `prif_put_strided_indirect`                      | **YES** |  |
| `prif_put_strided_with_notify`                   | **YES** |  |
| `prif_put_strided_with_notify_indirect`          | **YES** |  |
| `prif_put_strided_indirect_with_notify`          | **YES** |  |
| `prif_put_strided_indirect_with_notify_indirect` | **YES** |  |

---

## SYNC Statements

| Procedure | Status | Notes |
|-----------|--------|-------|
| `prif_sync_memory` | **YES** |  |
| `prif_sync_all`    | **YES** |  |
| `prif_sync_images` | **YES** |  |
| `prif_sync_team`   | **YES** |  |

---

## Locks and Unlocks
### Support = no

<!---
| Procedure | Status | Notes |
|-----------|--------|-------|
| `prif_lock`            | no  |  |
| `prif_lock_indirect`   | no  |  |
| `prif_unlock`          | no  |  |
| `prif_unlock_indirect` | no  |  |
-->

---

## Critical
### Support = no

<!---
| Procedure | Status | Notes |
|-----------|--------|-------|
| `prif_critical`     | no  |  |
| `prif_end_critical` | no  |  |
-->

---

## Events and Notifications

| Procedure | Status | Notes |
|-----------|--------|-------|
| `prif_event_post`          | **YES** |  |
| `prif_event_post_indirect` | **YES** |  |
| `prif_event_wait`          | **YES** |  |
| `prif_event_query`         | **YES** |  |
| `prif_notify_wait`         | **YES** |  |

---

## Teams

| Procedure | Status | Notes |
|-----------|--------|-------|
| `prif_form_team`   | **YES**   |  |
| `prif_get_team`    | **YES**   |  |
| `prif_team_number` | **YES**   |  |
| `prif_change_team` | **YES**   |  |
| `prif_end_team`    | **YES**   |  |

---

## Collectives

| Procedure | Status | Notes |
|-----------|--------|-------|
| `prif_co_broadcast`     | **YES** |  |
| `prif_co_max`           | **YES** |  |
| `prif_co_max_character` | **YES** |  |
| `prif_co_min`           | **YES** |  |
| `prif_co_min_character` | **YES** |  |
| `prif_co_sum`           | **YES** |  |
| `prif_co_reduce`        | **YES** |  |

---

## Atomic Memory Operations

| Procedure | Status | Notes |
|-----------|--------|-------|
| `prif_atomic_add`                     | **YES** |  |
| `prif_atomic_add_indirect`            | **YES** |  |
| `prif_atomic_and`                     | **YES** |  |
| `prif_atomic_and_indirect`            | **YES** |  |
| `prif_atomic_or`                      | **YES** |  |
| `prif_atomic_or_indirect`             | **YES** |  |
| `prif_atomic_xor`                     | **YES** |  |
| `prif_atomic_xor_indirect`            | **YES** |  |
| `prif_atomic_cas_int`                 | **YES** |  |
| `prif_atomic_cas_int_indirect`        | **YES** |  |
| `prif_atomic_cas_logical`             | **YES** |  |
| `prif_atomic_cas_logical_indirect`    | **YES** |  |
| `prif_atomic_fetch_add`               | **YES** |  |
| `prif_atomic_fetch_add_indirect`      | **YES** |  |
| `prif_atomic_fetch_and`               | **YES** |  |
| `prif_atomic_fetch_and_indirect`      | **YES** |  |
| `prif_atomic_fetch_or`                | **YES** |  |
| `prif_atomic_fetch_or_indirect`       | **YES** |  |
| `prif_atomic_fetch_xor`               | **YES** |  |
| `prif_atomic_fetch_xor_indirect`      | **YES** |  |
| `prif_atomic_define_int`              | **YES** |  |
| `prif_atomic_define_int_indirect`     | **YES** |  |
| `prif_atomic_define_logical`          | **YES** |  |
| `prif_atomic_define_logical_indirect` | **YES** |  |
| `prif_atomic_ref_int`                 | **YES** |  |
| `prif_atomic_ref_int_indirect`        | **YES** |  |
| `prif_atomic_ref_logical`             | **YES** |  |
| `prif_atomic_ref_logical_indirect`    | **YES** |  |

---
