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3 Copyright (c) 2019 Nokia
4 Copyright (c) 2018-2019 AT&T Intellectual Property.
6 Licensed under the Apache License, Version 2.0 (the "License");
7 you may not use this file except in compliance with the License.
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10 http://www.apache.org/licenses/LICENSE-2.0
12 Unless required by applicable law or agreed to in writing, software
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14 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 See the License for the specific language governing permissions and
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17 ==================================================================================
20 Mnemonic rmr_wh_send_msg_man.xfm
21 Abstract The manual page for the rmr_wh_send_msg function.
22 Author E. Scott Daniels
27 .im &{lib}/man/setup.im
31 &h1(RMR Library Functions)
40 rmr_mbuf_t* rmr_wh_send_msg( void* vctx, rmr_whid_t id, rmr_mbuf_t* msg );
45 The &cw(rmr_wh_send_msg) function accepts a message buffer from the user application
46 and attempts to send it using the wormhole ID provided (id).
47 Unlike &ital(rmr_send_msg,) this function attempts to send the message directly
48 to a process at the other end of a wormhole which was created with &ital(rmr_wh-open().)
49 When sending message via wormholes, the normal RMr routing based on message type is
50 ignored, and the caller may leave the message type unspecified in the message buffer
51 (unless it is needed by the receiving process).
54 The message buffer (msg) used to send is the same format as used for regular RMr
55 send and reply to sender operations, thus any buffer allocated by these means, or
56 calls to &ital(rmr_rcv_msg()) can be passed to this function.
58 .** pull in common retry text
59 .im &{lib}/man/retry.im
62 On success, a new message buffer, with an empty payload, is returned for the application
63 to use for the next send.
64 The state in this buffer will reflect the overall send operation state and should be
68 If the state in the returned buffer is anything other than &cw(RMR_OK,) the user application
69 may need to attempt a retransmission of the message, or take other action depending on the
70 setting of &cw(errno) as described below.
73 In the event of extreme failure, a NULL pointer is returned. In this case the value of
74 &cw(errno) might be of some use, for documentation, but there will be little that the
75 user application can do other than to move on.
78 The following values may be passed back in the &ital(state) field of the returned message
82 &beg_dlist(.75i : ^&bold_font )
83 &di(RMR_ERR_WHID) The wormhole ID passed in was not associated with an open wormhole, or was out of range for a valid ID.
84 &di(RMR_ERR_NOWHOPEN) No wormholes exist, further attempt to validate the ID are skipped.
85 &di(RMR_ERR_BADARG) The message buffer pointer did not refer to a valid message.
86 &di(RMR_ERR_NOHDR) The header in the message buffer was not valid or corrupted.
90 The following values may be assigned to &cw(errno) on failure.
91 &beg_dlist(.75i : ^&bold_font )
92 &di(INVAL) Parameter(s) passed to the function were not valid, or the underlying message processing environment was unable to interpret the message.
95 &di(ENOKEY) The header information in the message buffer was invalid.
98 &di(ENXIO) No known endpoint for the message could be found.
101 &di(EMSGSIZE) The underlying transport refused to accept the message because of a size value issue (message was not attempted to be sent).
104 &di(EFAULT) The message referenced by the message buffer is corrupt (NULL pointer or bad internal length).
107 &di(EBADF) Internal RMR error; information provided to the message transport environment was not valid.
110 &di(ENOTSUP) Sending was not supported by the underlying message transport.
113 &di(EFSM) The device is not in a state that can accept the message.
116 &di(EAGAIN) The device is not able to accept a message for sending. The user application should attempt to resend.
119 &di(EINTR) The operation was interrupted by delivery of a signal before the message was sent.
122 &di(ETIMEDOUT) The underlying message environment timed out during the send process.
125 &di(ETERM) The underlying message environment is in a shutdown state.
129 The following is a simple example of how the a wormhole is created (rmr_wh_open) and then
130 how &cw(rmr_wh_send_msg) function is used to send messages.
131 Some error checking is omitted for clarity.
136 #include <rmr/rmr.h> // system headers omitted for clarity
139 rmr_whid_t whid = -1; // wormhole id for sending
140 void* mrc; //msg router context
142 rmr_mbuf_t* sbuf; // send buffer
145 mrc = rmr_init( "43086", RMR_MAX_RCV_BYTES, RMRFL_NONE );
147 fprintf( stderr, "[FAIL] unable to initialise RMr environment\n" );
151 while( ! rmr_ready( mrc ) ) { // wait for routing table info
155 sbuf = rmr_alloc_msg( mrc, 2048 );
159 whid = rmr_wh_open( mrc, "localhost:6123" ); // open fails if endpoint refuses conn
160 if( RMR_WH_CONNECTED( wh ) ) {
161 snprintf( sbuf->payload, 1024, "periodic update from sender: %d", count++ );
162 sbuf->len = strlen( sbuf->payload );
163 sbuf = rmr_wh_send_msg( mrc, whid, sbuf );