-
-
.. 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_init
============================================================================================
-RMR Library Functions
-============================================================================================
-
-
-NAME
---------------------------------------------------------------------------------------------
+
+
+RMR LIBRARY FUNCTIONS
+=====================
+
+
+
+NAME
+----
+
rmr_init
-
-SYNOPSIS
---------------------------------------------------------------------------------------------
-
+
+
+SYNOPSIS
+--------
+
::
-
+
#include <rmr/rmr.h>
+
void* rmr_init( char* proto_port, int norm_msg_size, int flags );
-
-
-DESCRIPTION
---------------------------------------------------------------------------------------------
-
-The rmr_init function prepares the environment for sending
-and receiving messages. It does so by establishing a worker
-thread (pthread) which subscribes to a route table generator
-which provides the necessary routing information for the RMR
-library to send messages.
+
+
+DESCRIPTION
+-----------
+
+The ``rmr_init`` function prepares the environment for
+sending and receiving messages. It does so by establishing a
+worker thread (pthread) which subscribes to a route table
+generator which provides the necessary routing information
+for the RMR library to send messages.
*Port* is used to listen for connection requests from other
RMR based applications. The *norm_msg_size* parameter is used
footprint.
*Flags* allows for selection of some RMR options at the time
-of initialisation. These are set by ORing RMRFL constants
+of initialisation. These are set by ORing ``RMRFL`` constants
from the RMR header file. Currently the following flags are
supported:
-
-RMRFL_NONE
-
- No flags are set.
-
-
-RMRFL_NOTHREAD
-
- The route table collector thread is not to be started.
- This should only be used by the route table generator
- application if it is based on RMR.
-
-
-RMRFL_MTCALL
-
- Enable multi-threaded call support.
-
-
-RMRFL_NOLOCK
-
- Some underlying transport providers (e.g. SI95) enable
- locking to be turned off if the user application is single
- threaded, or otherwise can guarantee that RMR functions
- will not be invoked concurrently from different threads.
- Turning off locking can help make message receipt more
- efficient. If this flag is set when the underlying
- transport does not support disabling locks, it will be
- ignored.
-
-
-Multi-threaded Calling
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
+ .. list-table::
+ :widths: auto
+ :header-rows: 0
+ :class: borderless
+
+ * - **RMRFL_NONE**
+ -
+ No flags are set.
+
+
+ * - **RMRFL_NOTHREAD**
+ -
+ The route table collector thread is not to be started. This
+ should only be used by the route table generator application
+ if it is based on RMR.
+
+
+ * - **RMRFL_MTCALL**
+ -
+ Enable multi-threaded call support.
+
+
+ * - **RMRFL_NOLOCK**
+ -
+ Some underlying transport providers (e.g. SI95) enable
+ locking to be turned off if the user application is single
+ threaded, or otherwise can guarantee that RMR functions will
+ not be invoked concurrently from different threads. Turning
+ off locking can help make message receipt more efficient. If
+ this flag is set when the underlying transport does not
+ support disabling locks, it will be ignored.
+
+
+
+
+Multi-threaded Calling
+----------------------
+
The support for an application to issue a *blocking call* by
-the rmr_call() function was limited such that only user
+the ``rmr_call()`` function was limited such that only user
applications which were operating in a single thread could
safely use the function. Further, timeouts were message count
based and not time unit based. Multi-threaded call support
an additional process is necessary the user application must
"opt in" to this approach.
-
-ENVIRONMENT
---------------------------------------------------------------------------------------------
-
-As a part of the initialisation process rmr_init reads
+
+
+ENVIRONMENT
+-----------
+
+As a part of the initialisation process ``rmr_init`` reads
environment variables to configure itself. The following
variables are used if found.
-
-RMR_ASYNC_CONN
-
- Allows the async connection mode to be turned off (by
- setting the value to 0). When set to 1, or missing from
- the environment, RMR will invoke the connection interface
- in the transport mechanism using the non-blocking (async)
- mode. This will likely result in many "soft failures"
- (retry) until the connection is established, but allows
- the application to continue unimpeded should the
- connection be slow to set up.
-
-
-RMR_BIND_IF
-
- This provides the interface that RMR will bind listen
- ports to, allowing for a single interface to be used
- rather than listening across all interfaces. This should
- be the IP address assigned to the interface that RMR
- should listen on, and if not defined RMR will listen on
- all interfaces.
-
-
-RMR_CTL_PORT
-
- This variable defines the port that RMR should open for
- communications with Route Manager, and other RMR control
- applications. If not defined, the port 4561 is assumed.
-
- Previously, the RMR_RTG_SVC (route table generator service
- port) was used to define this port. However, a future
- version of Route Manager will require RMR to connect and
- request tables, thus that variable is now used to supply
- the Route Manager's well-known address and port.
-
- To maintain backwards compatibility with the older Route
- Manager versions, the presence of this variable in the
- environment will shift RMR's behaviour with respect to the
- default value used when RMR_RTG_SVC is **not** defined.
-
- When RMR_CTL_PORT is **defined:** RMR assumes that Route
- Manager requires RMR to connect and request table updates
- is made, and the default well-known address for Route
- manager is used (routemgr:4561).
-
- When RMR_CTL_PORT is **undefined:** RMR assumes that Route
- Manager will connect and push table updates, thus the
- default listen port (4561) is used.
-
- To avoid any possible misinterpretation and/or incorrect
- assumptions on the part of RMR, it is recommended that
- both the RMR_CTL_PORT and RMR_RTG_SVC be defined. In the
- case where both variables are defined, RMR will behave
- exactly as is communicated with the variable's values.
-
-
-RMR_RTG_SVC
-
- The value of this variable depends on the Route Manager in
- use.
-
- When the Route Manager is expecting to connect to an xAPP
- and push route tables, this variable must indicate the
- port which RMR should use to listen for these connections.
-
- When the Route Manager is expecting RMR to connect and
- request a table update during initialisation, the variable
- should be the host of the Route Manager process.
-
- The RMR_CTL_PORT variable (added with the support of
- sending table update requests to Route manager), controls
- the behaviour if this variable is not set. See the
- description of that variable for details.
-
-
-RMR_HR_LOG
-
- By default RMR writes messages to standard error
- (incorrectly referred to as log messages) in human
- readable format. If this environment variable is set to 0,
- the format of standard error messages might be written in
- some format not easily read by humans. If missing, a value
- of 1 is assumed.
-
-
-RMR_LOG_VLEVEL
-
- This is a numeric value which corresponds to the verbosity
- level used to limit messages written to standard error.
- The lower the number the less chatty RMR functions are
- during execution. The following is the current
- relationship between the value set on this variable and
- the messages written:
-
-
-0
-
- Off; no messages of any sort are written.
-
-
-1
-
- Only critical messages are written (default if this
- variable does not exist)
-
-
-2
-
- Errors and all messages written with a lower value.
-
-
-3
-
- Warnings and all messages written with a lower value.
-
-
-4
-
- Informational and all messages written with a lower
- value.
-
-
-5
-
- Debugging mode -- all messages written, however this
- requires RMR to have been compiled with debugging
- support enabled.
-
-
-
-RMR_RTG_ISRAW
-
- **Deprecated.** Should be set to 1 if the route table
- generator is sending "plain" messages (not using RMR to
- send messages), 0 if the RTG is using RMR to send. The
- default is 1 as we don't expect the RTG to use RMR.
-
- This variable is only recognised when using the NNG
- transport library as it is not possible to support NNG
- "raw" communications with other transport libraries. It is
- also necessary to match the value of this variable with
- the capabilities of the Route Manager; at some point in
- the future RMR will assume that all Route Manager messages
- will arrive via an RMR connection and will ignore this
- variable.
-
-RMR_SEED_RT
-
- This is used to supply a static route table which can be
- used for debugging, testing, or if no route table
- generator process is being used to supply the route table.
- If not defined, no static table is used and RMR will not
- report *ready* until a table is received. The static route
- table may contain both the route table (between newrt
- start and end records), and the MEID map (between meid_map
- start and end records).
-
-RMR_SRC_ID
-
- This is either the name or IP address which is placed into
- outbound messages as the message source. This will used
- when an RMR based application uses the rmr_rts_msg()
- function to return a response to the sender. If not
- supplied RMR will use the hostname which in some container
- environments might not be routable.
-
- The value of this variable is also used for Route Manager
- messages which are sent via an RMR connection.
-
-RMR_VCTL_FILE
-
- This supplies the name of a verbosity control file. The
- core RMR functions do not produce messages unless there is
- a critical failure. However, the route table collection
- thread, not a part of the main message processing
- component, can write additional messages to standard
- error. If this variable is set, RMR will extract the
- verbosity level for these messages (0 is silent) from the
- first line of the file. Changes to the file are detected
- and thus the level can be changed dynamically, however RMR
- will only suss out this variable during initialisation, so
- it is impossible to enable verbosity after startup.
-
-RMR_WARNINGS
-
- If set to 1, RMR will write some warnings which are
- non-performance impacting. If the variable is not defined,
- or set to 0, RMR will not write these additional warnings.
-
-
-RETURN VALUE
---------------------------------------------------------------------------------------------
-
-The rmr_init function returns a void pointer (a context if
-you will) that is passed as the first parameter to nearly all
-other RMR functions. If rmr_init is unable to properly
-initialise the environment, NULL is returned and errno is set
-to an appropriate value.
-
-ERRORS
---------------------------------------------------------------------------------------------
-
+ .. list-table::
+ :widths: auto
+ :header-rows: 0
+ :class: borderless
+
+ * - **RMR_ASYNC_CONN**
+ -
+ Allows the async connection mode to be turned off (by setting
+ the value to 0). When set to 1, or missing from the
+ environment, RMR will invoke the connection interface in the
+ transport mechanism using the non-blocking (async) mode. This
+ will likely result in many "soft failures" (retry) until the
+ connection is established, but allows the application to
+ continue unimpeded should the connection be slow to set up.
+
+ * - **RMR_BIND_IF**
+ -
+ This provides the interface that RMR will bind listen ports
+ to, allowing for a single interface to be used rather than
+ listening across all interfaces. This should be the IP
+ address assigned to the interface that RMR should listen on,
+ and if not defined RMR will listen on all interfaces.
+
+ * - **RMR_CTL_PORT**
+ -
+ This variable defines the port that RMR should open for
+ communications with Route Manager, and other RMR control
+ applications. If not defined, the port 4561 is assumed.
+
+ Previously, the ``RMR_RTG_SVC`` (route table generator
+ service port) was used to define this port. However, a future
+ version of Route Manager will require RMR to connect and
+ request tables, thus that variable is now used to supply the
+ Route Manager's well-known address and port.
+
+ To maintain backwards compatibility with the older Route
+ Manager versions, the presence of this variable in the
+ environment will shift RMR's behaviour with respect to the
+ default value used when ``RMR_RTG_SVC`` is **not** defined.
+
+ When ``RMR_CTL_PORT`` is **defined:** RMR assumes that Route
+ Manager requires RMR to connect and request table updates is
+ made, and the default well-known address for Route manager is
+ used (routemgr:4561).
+
+ When ``RMR_CTL_PORT`` is **undefined:** RMR assumes that
+ Route Manager will connect and push table updates, thus the
+ default listen port (4561) is used.
+
+ To avoid any possible misinterpretation and/or incorrect
+ assumptions on the part of RMR, it is recommended that both
+ the ``RMR_CTL_PORT`` and ``RMR_RTG_SVC`` be defined. In the
+ case where both variables are defined, RMR will behave
+ exactly as is communicated with the variable's values.
+
+ * - **RMR_RTG_SVC**
+ -
+ The value of this variable depends on the Route Manager in
+ use.
+
+ When the Route Manager is expecting to connect to an xAPP and
+ push route tables, this variable must indicate the
+ ``port`` which RMR should use to listen for these
+ connections.
+
+ When the Route Manager is expecting RMR to connect and
+ request a table update during initialisation, the variable
+ should be the ``host`` of the Route Manager process.
+
+ The ``RMR_CTL_PORT`` variable (added with the support of
+ sending table update requests to Route manager), controls the
+ behaviour if this variable is not set. See the description of
+ that variable for details.
+
+ * - **RMR_HR_LOG**
+ -
+ By default RMR writes messages to standard error (incorrectly
+ referred to as log messages) in human readable format. If
+ this environment variable is set to 0, the format of standard
+ error messages might be written in some format not easily
+ read by humans. If missing, a value of 1 is assumed.
+
+ * - **RMR_LOG_VLEVEL**
+ -
+ This is a numeric value which corresponds to the verbosity
+ level used to limit messages written to standard error. The
+ lower the number the less chatty RMR functions are during
+ execution. The following is the current relationship between
+ the value set on this variable and the messages written:
+
+
+ .. list-table::
+ :widths: auto
+ :header-rows: 0
+ :class: borderless
+
+ * - **0**
+ -
+ Off; no messages of any sort are written.
+
+ * - **1**
+ -
+ Only critical messages are written (default if this variable
+ does not exist)
+
+ * - **2**
+ -
+ Errors and all messages written with a lower value.
+
+ * - **3**
+ -
+ Warnings and all messages written with a lower value.
+
+ * - **4**
+ -
+ Informational and all messages written with a lower value.
+
+ * - **5**
+ -
+ Debugging mode -- all messages written, however this requires
+ RMR to have been compiled with debugging support enabled.
+
+
+
+ * - **RMR_RTG_ISRAW**
+ -
+ **Deprecated.** Should be set to 1 if the route table
+ generator is sending "plain" messages (not using RMR to send
+ messages), 0 if the RTG is using RMR to send. The default is
+ 1 as we don't expect the RTG to use RMR.
+
+ This variable is only recognised when using the NNG transport
+ library as it is not possible to support NNG "raw"
+ communications with other transport libraries. It is also
+ necessary to match the value of this variable with the
+ capabilities of the Route Manager; at some point in the
+ future RMR will assume that all Route Manager messages will
+ arrive via an RMR connection and will ignore this variable.
+
+ * - **RMR_SEED_RT**
+ -
+ This is used to supply a static route table which can be used
+ for debugging, testing, or if no route table generator
+ process is being used to supply the route table. If not
+ defined, no static table is used and RMR will not report
+ *ready* until a table is received. The static route table may
+ contain both the route table (between newrt start and end
+ records), and the MEID map (between meid_map start and end
+ records).
+
+ * - **RMR_SRC_ID**
+ -
+ This is either the name or IP address which is placed into
+ outbound messages as the message source. This will used when
+ an RMR based application uses the rmr_rts_msg() function to
+ return a response to the sender. If not supplied RMR will use
+ the hostname which in some container environments might not
+ be routable.
+
+ The value of this variable is also used for Route Manager
+ messages which are sent via an RMR connection.
+
+ * - **RMR_VCTL_FILE**
+ -
+ This supplies the name of a verbosity control file. The core
+ RMR functions do not produce messages unless there is a
+ critical failure. However, the route table collection thread,
+ not a part of the main message processing component, can
+ write additional messages to standard error. If this variable
+ is set, RMR will extract the verbosity level for these
+ messages (0 is silent) from the first line of the file.
+ Changes to the file are detected and thus the level can be
+ changed dynamically, however RMR will only suss out this
+ variable during initialisation, so it is impossible to enable
+ verbosity after startup.
+
+ * - **RMR_WARNINGS**
+ -
+ If set to 1, RMR will write some warnings which are
+ non-performance impacting. If the variable is not defined, or
+ set to 0, RMR will not write these additional warnings.
+
+
+
+
+RETURN VALUE
+------------
+
+The ``rmr_init`` function returns a void pointer (a context
+if you will) that is passed as the first parameter to nearly
+all other RMR functions. If ``rmr_init`` is unable to
+properly initialise the environment, NULL is returned and
+errno is set to an appropriate value.
+
+
+ERRORS
+------
+
The following error values are specifically set by this RMR
function. In some cases the error message of a system call is
propagated up, and thus this list might be incomplete.
-
-ENOMEM
-
- Unable to allocate memory.
-
-
-EXAMPLE
---------------------------------------------------------------------------------------------
-
+ .. list-table::
+ :widths: auto
+ :header-rows: 0
+ :class: borderless
+
+ * - **ENOMEM**
+ -
+ Unable to allocate memory.
+
+
+
+
+EXAMPLE
+-------
+
::
-
+
void* uh;
rmr_mbuf* buf = NULL;
+
uh = rmr_init( "43086", 4096, 0 );
buf = rmr_rcv_msg( uh, buf );
-
-
-SEE ALSO
---------------------------------------------------------------------------------------------
-
+
+
+SEE ALSO
+--------
+
rmr_alloc_msg(3), rmr_call(3), rmr_free_msg(3),
rmr_get_rcvfd(3), rmr_mt_call(3), rmr_mt_rcv(3),
rmr_payload_size(3), rmr_send_msg(3), rmr_rcv_msg(3),
Code Review / ric-plt / lib / rmr.git / blobdiff