X-Git-Url: https://gerrit.o-ran-sc.org/r/gitweb?a=blobdiff_plain;f=docs%2Frmr_wh_call.3.rst;h=1024ca341452b9d1a8ab238da95e36f3282a0693;hb=f447e29dffd0a24fcf02288b9591ce7d03a8fb9d;hp=9e6da4e1377a3a6f29a24472696026b1141deedd;hpb=3bcb5b17e0b713d7a61389dcafa0d92a0704a7fb;p=ric-plt%2Flib%2Frmr.git diff --git a/docs/rmr_wh_call.3.rst b/docs/rmr_wh_call.3.rst index 9e6da4e..1024ca3 100644 --- a/docs/rmr_wh_call.3.rst +++ b/docs/rmr_wh_call.3.rst @@ -1,14 +1,14 @@ -.. 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_wh_call -============================================================================================ - - +.. 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_wh_call +============================================================================================ + + RMR LIBRARY FUNCTIONS @@ -19,208 +19,208 @@ RMR LIBRARY FUNCTIONS NAME ---- -rmr_wh_call +rmr_wh_call SYNOPSIS -------- - -:: - - #include - - rmr_mbuf_t* rmr_wh_call( void* vctx, rmr_whid_t whid, rmr_mbuf_t* msg, int call_id, int max_wait ) - - + +:: + + #include + + rmr_mbuf_t* rmr_wh_call( void* vctx, rmr_whid_t whid, rmr_mbuf_t* msg, int call_id, int max_wait ) + + DESCRIPTION ----------- -The ``rmr_wh_call`` function accepts a message buffer (msg) -from the user application and attempts to send it using the -wormhole ID provided (whid). If the send is successful, the -call will block until either a response message is received, -or the ``max_wait`` number of milliseconds has passed. In -order for the response to be recognised as a response, the -remote process **must** use ``rmr_rts_msg()`` to send their -response. - -Like *rmr_wh_send_msg,* this function attempts to send the -message directly to a process at the other end of a wormhole -which was created with *rmr_wh_open().* When sending message -via wormholes, the normal RMR routing based on message type -is ignored, and the caller may leave the message type -unspecified in the message buffer (unless it is needed by the -receiving process). The ``call_id`` parameter is a number in -the range of 2 through 255 and is used to identify the -calling thread in order to properly match a response message -when it arrives. Providing this value, and ensuring the -proper uniqueness, is the responsibility of the user -application and as such the ability to use the -``rmr_wh_call()`` function from potentially non-threaded -concurrent applications (such as Go's goroutines) is -possible. +The ``rmr_wh_call`` function accepts a message buffer (msg) +from the user application and attempts to send it using the +wormhole ID provided (whid). If the send is successful, the +call will block until either a response message is received, +or the ``max_wait`` number of milliseconds has passed. In +order for the response to be recognised as a response, the +remote process **must** use ``rmr_rts_msg()`` to send their +response. + +Like *rmr_wh_send_msg,* this function attempts to send the +message directly to a process at the other end of a wormhole +which was created with *rmr_wh_open().* When sending message +via wormholes, the normal RMR routing based on message type +is ignored, and the caller may leave the message type +unspecified in the message buffer (unless it is needed by the +receiving process). The ``call_id`` parameter is a number in +the range of 2 through 255 and is used to identify the +calling thread in order to properly match a response message +when it arrives. Providing this value, and ensuring the +proper uniqueness, is the responsibility of the user +application and as such the ability to use the +``rmr_wh_call()`` function from potentially non-threaded +concurrent applications (such as Go's goroutines) is +possible. Retries ------- -The send operations in RMR will retry *soft* send failures -until one of three conditions occurs: - - -* The message is sent without error - -* The underlying transport reports a *hard* failure - -* The maximum number of retry loops has been attempted - - -A retry loop consists of approximately 1000 send attempts -**without** any intervening calls to *sleep()* or *usleep().* -The number of retry loops defaults to 1, thus a maximum of -1000 send attempts is performed before returning to the user -application. This value can be set at any point after RMR -initialisation using the *rmr_set_stimeout()* function -allowing the user application to completely disable retires -(set to 0), or to increase the number of retry loops. +The send operations in RMR will retry *soft* send failures +until one of three conditions occurs: + + +* The message is sent without error + +* The underlying transport reports a *hard* failure + +* The maximum number of retry loops has been attempted + + +A retry loop consists of approximately 1000 send attempts +**without** any intervening calls to *sleep()* or *usleep().* +The number of retry loops defaults to 1, thus a maximum of +1000 send attempts is performed before returning to the user +application. This value can be set at any point after RMR +initialisation using the *rmr_set_stimeout()* function +allowing the user application to completely disable retires +(set to 0), or to increase the number of retry loops. Transport Level Blocking ------------------------ -The underlying transport mechanism used to send messages is -configured in *non-blocking* mode. This means that if a -message cannot be sent immediately the transport mechanism -will **not** pause with the assumption that the inability to -send will clear quickly (within a few milliseconds). This -means that when the retry loop is completely disabled (set to -0), that the failure to accept a message for sending by the -underlying mechanisms (software or hardware) will be reported -immediately to the user application. - -It should be noted that depending on the underlying transport -mechanism being used, it is extremely likely that retry -conditions will happen during normal operations. These are -completely out of RMR's control, and there is nothing that -RMR can do to avoid or mitigate these other than by allowing -RMR to retry the send operation, and even then it is possible -(e.g., during connection reattempts), that a single retry -loop is not enough to guarantee a successful send. +The underlying transport mechanism used to send messages is +configured in *non-blocking* mode. This means that if a +message cannot be sent immediately the transport mechanism +will **not** pause with the assumption that the inability to +send will clear quickly (within a few milliseconds). This +means that when the retry loop is completely disabled (set to +0), that the failure to accept a message for sending by the +underlying mechanisms (software or hardware) will be reported +immediately to the user application. + +It should be noted that depending on the underlying transport +mechanism being used, it is extremely likely that retry +conditions will happen during normal operations. These are +completely out of RMR's control, and there is nothing that +RMR can do to avoid or mitigate these other than by allowing +RMR to retry the send operation, and even then it is possible +(e.g., during connection reattempts), that a single retry +loop is not enough to guarantee a successful send. RETURN VALUE ------------ -On success, new message buffer, with the payload containing -the response from the remote endpoint is returned. The state -in this buffer will reflect the overall send operation state -and should be ``RMR_OK.`` - -If a message is returned with a state which is anything other -than ``RMR_OK,`` the indication is that the send was not -successful. The user application must check the state and -determine the course of action. If the return value is NULL, -no message, the indication is that there was no response -received within the timeout (max_wait) period of time. +On success, new message buffer, with the payload containing +the response from the remote endpoint is returned. The state +in this buffer will reflect the overall send operation state +and should be ``RMR_OK.`` + +If a message is returned with a state which is anything other +than ``RMR_OK,`` the indication is that the send was not +successful. The user application must check the state and +determine the course of action. If the return value is NULL, +no message, the indication is that there was no response +received within the timeout (max_wait) period of time. ERRORS ------ -The following values may be passed back in the *state* field -of the returned message buffer. - - - .. list-table:: - :widths: auto - :header-rows: 0 - :class: borderless - - * - **RMR_ERR_WHID** - - - The wormhole ID passed in was not associated with an open - wormhole, or was out of range for a valid ID. - - * - **RMR_ERR_NOWHOPEN** - - - No wormholes exist, further attempt to validate the ID are - skipped. - - * - **RMR_ERR_BADARG** - - - The message buffer pointer did not refer to a valid message. - - * - **RMR_ERR_NOHDR** - - - The header in the message buffer was not valid or corrupted. - - +The following values may be passed back in the *state* field +of the returned message buffer. + + + .. list-table:: + :widths: auto + :header-rows: 0 + :class: borderless + + * - **RMR_ERR_WHID** + - + The wormhole ID passed in was not associated with an open + wormhole, or was out of range for a valid ID. + + * - **RMR_ERR_NOWHOPEN** + - + No wormholes exist, further attempt to validate the ID are + skipped. + + * - **RMR_ERR_BADARG** + - + The message buffer pointer did not refer to a valid message. + + * - **RMR_ERR_NOHDR** + - + The header in the message buffer was not valid or corrupted. + + EXAMPLE ------- -The following is a simple example of how the a wormhole is -created (rmr_wh_open) and then how ``rmr_wh_send_msg`` -function is used to send messages. Some error checking is -omitted for clarity. - - -:: - - - #include // system headers omitted for clarity - - int main() { - rmr_whid_t whid = -1; // wormhole id for sending - void* mrc; //msg router context - int i; - rmr_mbuf_t* sbuf; // send buffer - int count = 0; - int norm_msg_size = 1500; // most messages fit in this size - - mrc = rmr_init( "43086", norm_msg_size, RMRFL_NONE ); - if( mrc == NULL ) { - fprintf( stderr, "[FAIL] unable to initialise RMR environment\\n" ); - exit( 1 ); - } - - while( ! rmr_ready( mrc ) ) { // wait for routing table info - sleep( 1 ); - } - - sbuf = rmr_alloc_msg( mrc, 2048 ); - - while( 1 ) { - if( whid < 0 ) { - whid = rmr_wh_open( mrc, "localhost:6123" ); // open fails if endpoint refuses conn - if( RMR_WH_CONNECTED( wh ) ) { - snprintf( sbuf->payload, 1024, "periodic update from sender: %d", count++ ); - sbuf->len = strlen( sbuf->payload ); - sbuf = rmr_wh_call( mrc, whid, sbuf, 1000 ); // expect a response in 1s or less - if( sbuf != NULL && sbuf->state = RMR_OK ) { - sprintf( stderr, "response: %s\\n", sbuf->payload ); // assume they sent a string - } else { - sprintf( stderr, "response not received, or send error\\n" ); - } - } - } - - sleep( 5 ); - } - } - +The following is a simple example of how the a wormhole is +created (rmr_wh_open) and then how ``rmr_wh_send_msg`` +function is used to send messages. Some error checking is +omitted for clarity. + + +:: + + + #include // system headers omitted for clarity + + int main() { + rmr_whid_t whid = -1; // wormhole id for sending + void* mrc; //msg router context + int i; + rmr_mbuf_t* sbuf; // send buffer + int count = 0; + int norm_msg_size = 1500; // most messages fit in this size + + mrc = rmr_init( "43086", norm_msg_size, RMRFL_NONE ); + if( mrc == NULL ) { + fprintf( stderr, "[FAIL] unable to initialise RMR environment\\n" ); + exit( 1 ); + } + + while( ! rmr_ready( mrc ) ) { // wait for routing table info + sleep( 1 ); + } + + sbuf = rmr_alloc_msg( mrc, 2048 ); + + while( 1 ) { + if( whid < 0 ) { + whid = rmr_wh_open( mrc, "localhost:6123" ); // open fails if endpoint refuses conn + if( RMR_WH_CONNECTED( wh ) ) { + snprintf( sbuf->payload, 1024, "periodic update from sender: %d", count++ ); + sbuf->len = strlen( sbuf->payload ); + sbuf = rmr_wh_call( mrc, whid, sbuf, 1000 ); // expect a response in 1s or less + if( sbuf != NULL && sbuf->state = RMR_OK ) { + sprintf( stderr, "response: %s\\n", sbuf->payload ); // assume they sent a string + } else { + sprintf( stderr, "response not received, or send error\\n" ); + } + } + } + + sleep( 5 ); + } + } + SEE ALSO -------- -rmr_alloc_msg(3), rmr_call(3), rmr_free_msg(3), rmr_init(3), -rmr_payload_size(3), rmr_rcv_msg(3), rmr_rcv_specific(3), -rmr_rts_msg(3), rmr_ready(3), rmr_fib(3), rmr_has_str(3), -rmr_tokenise(3), rmr_mk_ring(3), rmr_ring_free(3), -rmr_set_stimeout(3), rmr_wh_open(3), rmr_wh_close(3), -rmr_wh_state(3) +rmr_alloc_msg(3), rmr_call(3), rmr_free_msg(3), rmr_init(3), +rmr_payload_size(3), rmr_rcv_msg(3), rmr_rcv_specific(3), +rmr_rts_msg(3), rmr_ready(3), rmr_fib(3), rmr_has_str(3), +rmr_tokenise(3), rmr_mk_ring(3), rmr_ring_free(3), +rmr_set_stimeout(3), rmr_wh_open(3), rmr_wh_close(3), +rmr_wh_state(3)