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Name

linx_send() - Send a signal buffer through a LINX endpoint to another LINX endpoint (spid)

linx_send_w_s() - Send a signal buffer, but specify a different LINX endpoint

as sender

Synopsis

#include <linx_types.h>
#include <linx.h>

int linx_send(LINX *linx, union LINX_SIGNAL **sig, LINX_SPID to);

int linx_send_w_s(LINX *linx, union LINX_SIGNAL **sig, LINX_SPID from, LINX_SPID to);

Description

Send a signal buffer to the LINX endpoint, identified by the to binary identifier (also called spid). The linx_send() call consumes the signal buffer, transferring the buffer ownership, and sets the sig pointer to LINX_NIL. The buffer is consumed also if an error occurs and the message cannot be delivered to the intended recipient.

linx is the handle to the LINX endpoint, via which the signal buffer is transmitted.


sig is the signal buffer to send. The buffer must be owned by the transmitting LINX endpoint. It could have been allocated with linx_alloc(3) or received via the same LINX endpoint.

to is the identifier (spid) of the recipent LINX endpoint, usually found as a result of a linx_hunt(3) .

from is the identifier (spid) of a different sender endpoint (instead of the transmitting endpoint). The recipient will see this spid as the sender of the signal. Also this spid is usually found as a result of a linx_hunt(3) .

If linx is not a valid LINX endpoint, i.e. created with linx_open(3) then abort(3) is called.

Return Value

Returns 0 if successful. On failure, -1 is returned and errno will be set. In any case, sig is set to LINX_NIL.

Errors

EINVAL if sig, to or, if applicable, from are invalid.

EBADF, ENOTSOCK if the underlying LINX endpoint structure contains an invalid descriptor, or a descriptor which is not a socket descriptor.

EINTR The call was interrupted by an OS signal.

ENOMEM if there is not enough memory.

ECONNRESET This error is reported at an attempt to send to the spid of an already closed LINX endpoint (which existed previously), also called a zombie endpoint. However this situation is best avoided by using linx_attach(3) to supervise the receiving LINX endpoint. A zombie spid stays until a counter overflow causes reuse of spid instances.

EPIPE This error is reported at an attempt to send to the spid of a LINX endpoint that is being closed as the call occurs.

Bugs/Limitations

None.

Notes

It is illegal to allocate/receive a signal buffer on one LINX endpoint and then send it using linx_send(3) from another LINX endpoint. In that case a new signal buffer needs to be allocated and the buffer contents moved to the new signal buffers prior to sending it. 

    union LINX_SIGNAL *sig1, *sig2;
    LINX_OSBUFSIZE size;
    LINX_SIGSELECT sel[] = {0};
    struct LINX *linx1, *linx2;
    LINX_SPID to_spid;
    ...
    sig1 = linx_receive(linx1, &sig1, sel);
    size = linx_sigsize(linx1, sig1);
    sig2 = linx_alloc(linx2, size, sel);
    memcpy((void)sig2, (void)sig1, size);
    (void)linx_free_buf(linx1, &sig1);
    (void)linx_send(linx2, &sig2, to_spid);
    ...

See Also

linx(7) , linx_alloc(3) , linx_hunt(3) , linx_receive(3) , linx_receive_w_tmo(3) , linx_receive_from(3) , linx_receive_w_buf(3)

Author

Enea LINX team

Copyright

Copyright (c) 2006-2007, Enea Software AB All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. Neither the name of Enea Software AB nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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