Update docs

cpp/include/ucxx/typedefs.h

@@ -65,21 +65,28 @@ enum Tag : ucp_tag_t {};
  */
 enum TagMask : ucp_tag_t {};
 
-struct TagRecvInfo {
-  Tag senderTag;  ///< Sender tag
-  size_t length;  ///< The size of the received data
-
-  TagRecvInfo() = delete;
-  explicit TagRecvInfo(const ucp_tag_recv_info_t&);
-};
-
 /**
  * @brief A full UCP tag mask.
  *
  * A convenience constant providing a full UCP tag mask (all bits set).
  */
 static constexpr TagMask TagMaskFull{std::numeric_limits<std::underlying_type_t<TagMask>>::max()};
 
+/**
+ * @brief Information about probed tag message.
+ *
+ * Contains information returned when probing by a tag message received by the worker but
+ * not yet consumed.
+ */
+class TagRecvInfo {
+ public:
+  Tag senderTag;  ///< Sender tag
+  size_t length;  ///< The size of the received data
+
+  TagRecvInfo() = delete;
+  explicit TagRecvInfo(const ucp_tag_recv_info_t&);
+};
+
 /**
  * @brief A UCP configuration map.
  *
@@ -132,7 +139,8 @@ typedef std::function<std::shared_ptr<Buffer>(size_t)> AmAllocatorType;
  * @brief Active Message receiver callback.
  *
  * Type for a custom Active Message receiver callback, executed by the remote worker upon
- * Active Message request completion.
+ * Active Message request completion. The first parameter is the request that completed,
+ * the second is the handle of the UCX endpoint of the sender.
  */
 typedef std::function<void(std::shared_ptr<Request>, ucp_ep_h)> AmReceiverCallbackType;
 

cpp/include/ucxx/worker.h

@@ -685,19 +685,26 @@ class Worker : public Component {
    *
    * Checks the worker for any uncaught tag messages. An uncaught tag message is any
    * tag message that has been fully or partially received by the worker, but not matched
-   * by a corresponding `ucp_tag_recv_*` call.
+   * by a corresponding `ucp_tag_recv_*` call. Additionally, returns information about the
+   * tag message.
    *
    * @code{.cpp}
    * // `worker` is `std::shared_ptr<ucxx::Worker>`
-   * assert(!worker->tagProbe(0));
+   * auto probe = worker->tagProbe(0);
+   * assert(!probe.first)
    *
    * // `ep` is a remote `std::shared_ptr<ucxx::Endpoint` to the local `worker`
    * ep->tagSend(buffer, length, 0);
    *
-   * assert(worker->tagProbe(0));
+   * probe = worker->tagProbe(0);
+   * assert(probe.first);
+   * assert(probe.second.tag == 0);
+   * assert(probe.second.length == length);
    * @endcode
    *
-   * @returns `true` if any uncaught messages were received, `false` otherwise.
+   * @returns pair where first elements is `true` if any uncaught messages were received,
+   *          `false` otherwise, and second element contain the information from the tag
+   *          receive.
    */
   [[nodiscard]] std::pair<bool, TagRecvInfo> tagProbe(const Tag tag,
                                                       const TagMask tagMask = TagMaskFull);