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.TH iob_send 3
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.SH NAME
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iob_send \- send I/O batch
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.SH SYNTAX
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.B #include <libowfat/iob.h>
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int64 \fBiob_send\fP(int64 s,io_batch* b);
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.SH DESCRIPTION
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iob_send sends the (rest of) \fIb\fR over the socket \fIs\fR.
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iob_send returns the number of bytes written, 0 if there were no more
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bytes to be written in the batch, -1 for EAGAIN, or -3 for a permanent
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error (for example "connection reset by peer").
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The normal usage pattern is using io_wait to know when a descriptor is
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writable, and then calling iob_send until it returns 0, -1 or -3.
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If it returns 0, terminate the loop (everything was written OK). If it
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returns -1, call io_wait again. If it returned -3, signal an error and
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close the socket.
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The benefit of the I/O batch API is that it exploits platform specific
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APIs like FreeBSD's sendfile. The file contents will always be sent in
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a way that allows the operating systems to perform zero copy TCP, and
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the buffers will always be sent using as few syscalls as possible and
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avoiding unnecessary copying (using writev).
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.SH "SEE ALSO"
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iob_reset(3), iob_send(3), iob_addbuf(3), iob_adds_free(3), iob_addfile(3),
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iob_prefetch(3)
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