-
-
.. This work is licensed under a Creative Commons Attribution 4.0 International License.
.. SPDX-License-Identifier: CC-BY-4.0
.. CAUTION: this document is generated from source in doc/src/rtd.
.. To make changes edit the source and recompile the document.
.. Do NOT make changes directly to .rst or .md files.
-
============================================================================================
Man Page: rmr_rcv_msg
============================================================================================
-RMR Library Functions
-============================================================================================
-
-
-NAME
---------------------------------------------------------------------------------------------
+
+
+RMR LIBRARY FUNCTIONS
+=====================
+
+
+
+NAME
+----
+
rmr_rcv_msg
-
-SYNOPSIS
---------------------------------------------------------------------------------------------
-
+
+
+SYNOPSIS
+--------
+
::
-
+
#include <rmr/rmr.h>
+
rmr_mbuf_t* rmr_rcv_msg( void* vctx, rmr_mbuf_t* old_msg );
-
-
-DESCRIPTION
---------------------------------------------------------------------------------------------
-
-The rmr_rcv_msg function blocks until a message is received,
-returning the message to the caller via a pointer to a
-rmr_mbuf_t structure type. If messages were queued while
-waiting for the response to a previous invocation of
-rmr_call, the oldest message is removed from the queue and
-returned without delay.
-
-The *vctx* pointer is the pointer returned by the rmr_init
-function. *Old_msg* is a pointer to a previously used message
-buffer or NULL. The ability to reuse message buffers helps to
-avoid alloc/free cycles in the user application. When no
-buffer is available to supply, the receive function will
-allocate one.
-
-RETURN VALUE
---------------------------------------------------------------------------------------------
-
-The function returns a pointer to the rmr_mbuf_t structure
-which references the message information (state, length,
-payload), or a nil pointer in the case of an extreme error.
-
-ERRORS
---------------------------------------------------------------------------------------------
-
-The *state* field in the message buffer will indicate RMR_OK
-when the message receive process was successful and the
-message can be used by the caller. Depending on the
+
+
+DESCRIPTION
+-----------
+
+The ``rmr_rcv_msg`` function blocks until a message is
+received, returning the message to the caller via a pointer
+to a ``rmr_mbuf_t`` structure type. If messages were queued
+while waiting for the response to a previous invocation of
+``rmr_call,`` the oldest message is removed from the queue
+and returned without delay.
+
+The *vctx* pointer is the pointer returned by the
+``rmr_init`` function. *Old_msg* is a pointer to a previously
+used message buffer or NULL. The ability to reuse message
+buffers helps to avoid alloc/free cycles in the user
+application. When no buffer is available to supply, the
+receive function will allocate one.
+
+
+RETURN VALUE
+------------
+
+The function returns a pointer to the ``rmr_mbuf_t``
+structure which references the message information (state,
+length, payload), or a nil pointer in the case of an extreme
+error.
+
+
+ERRORS
+------
+
+The *state* field in the message buffer will indicate
+``RMR_OK`` when the message receive process was successful
+and the message can be used by the caller. Depending on the
underlying transport mechanism, one of the following RMR
error stats may be returned:
-
-RMR_ERR_EMPTY
-
- The message received had no payload, or was completely
- empty.
-
-
-RMR_ERR_TIMEOUT
-
- For some transport mechanisms, or if reading the receive
- queue from multiple threads, it is possible for one thread
- to find no data waiting when it queries the queue. When
- this state is reported, the message buffer does not
- contain message data and the user application should
- reinvoke the receive function.
-
-
-When an RMR error state is reported, the underlying errno
-value might provide more information. The following is a list
-of possible values that might accompany the states listed
-above:
-
-RMR_ERR_EMPTY if an empty message was received. If a nil
+ .. list-table::
+ :widths: auto
+ :header-rows: 0
+ :class: borderless
+
+ * - **RMR_ERR_EMPTY**
+ -
+ The message received had no payload, or was completely empty.
+
+
+ * - **RMR_ERR_TIMEOUT**
+ -
+ For some transport mechanisms, or if reading the receive
+ queue from multiple threads, it is possible for one thread to
+ find no data waiting when it queries the queue. When this
+ state is reported, the message buffer does not contain
+ message data and the user application should reinvoke the
+ receive function.
+
+
+
+When an RMR error state is reported, the underlying
+``errno`` value might provide more information. The following
+is a list of possible values that might accompany the states
+listed above:
+
+``RMR_ERR_EMPTY`` if an empty message was received. If a nil
pointer is returned, or any other state value was set in the
-message buffer, errno will be set to one of the following:
-
-
-
-INVAL
-
- Parameter(s) passed to the function were not valid.
-
-
-EBADF
-
- The underlying message transport is unable to process the
- request.
-
-
-ENOTSUP
-
- The underlying message transport is unable to process the
- request.
-
-
-EFSM
-
- The underlying message transport is unable to process the
- request.
-
-
-EAGAIN
-
- The underlying message transport is unable to process the
- request.
-
-
-EINTR
-
- The underlying message transport is unable to process the
- request.
-
-
-ETIMEDOUT
-
- The underlying message transport is unable to process the
- request.
-
-
-ETERM
-
- The underlying message transport is unable to process the
- request.
-
-
-EXAMPLE
---------------------------------------------------------------------------------------------
-
-
-SEE ALSO
---------------------------------------------------------------------------------------------
-
+message buffer, ``errno`` will be set to one of the
+following:
+
+
+ .. list-table::
+ :widths: auto
+ :header-rows: 0
+ :class: borderless
+
+ * - **INVAL**
+ -
+ Parameter(s) passed to the function were not valid.
+
+ * - **EBADF**
+ -
+ The underlying message transport is unable to process the
+ request.
+
+ * - **ENOTSUP**
+ -
+ The underlying message transport is unable to process the
+ request.
+
+ * - **EFSM**
+ -
+ The underlying message transport is unable to process the
+ request.
+
+ * - **EAGAIN**
+ -
+ The underlying message transport is unable to process the
+ request.
+
+ * - **EINTR**
+ -
+ The underlying message transport is unable to process the
+ request.
+
+ * - **ETIMEDOUT**
+ -
+ The underlying message transport is unable to process the
+ request.
+
+ * - **ETERM**
+ -
+ The underlying message transport is unable to process the
+ request.
+
+
+
+
+EXAMPLE
+-------
+
+
+
+SEE ALSO
+--------
+
rmr_alloc_msg(3), rmr_call(3), rmr_free_msg(3),
rmr_get_rcvfd(3), rmr_init(3), rmr_mk_ring(3),
rmr_payload_size(3), rmr_send_msg(3), rmr_torcv_msg(3),
Code Review / ric-plt / lib / rmr.git / blobdiff