forked from Imagelibrary/rtems
9b4422a251
Script does what is expected and tries to do it as smartly as possible. + remove occurrences of two blank comment lines next to each other after Id string line removed. + remove entire comment blocks which only exited to contain CVS Ids + If the processing left a blank line at the top of a file, it was removed.
45 lines
1.6 KiB
Perl
45 lines
1.6 KiB
Perl
@c
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@c Written by Eric Norum
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@c
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@c COPYRIGHT (c) 1988-2002.
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@c On-Line Applications Research Corporation (OAR).
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@c All rights reserved.
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@chapter Network Task Structure and Data Flow
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A schematic diagram of the tasks and message @b{mbuf} queues in a
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simple RTEMS networking application is shown in the following
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figure:
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@ifclear use-html
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@image{networkflow,5in,6in,"Network Task Structure and Data Flow"}
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@end ifclear
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@ifset use-html
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@html
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<IMG SRC="networkflow.jpg" ALIGN=CENTER
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ALT="Network Task Structure and Data Flow">
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@end html
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@end ifset
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The transmit task for each network interface is normally blocked waiting
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for a packet to arrive in the transmit queue. Once a packet arrives, the
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transmit task may block waiting for an event from the transmit interrupt
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handler. The transmit interrupt handler sends an RTEMS event to the transmit
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task to indicate that transmit hardware resources have become available.
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The receive task for each network interface is normally blocked waiting
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for an event from the receive interrupt handler. When this event is received
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the receive task reads the packet and forwards it to the network stack
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for subsequent processing by the network task.
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The network task processes incoming packets and takes care of
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timed operations such as handling TCP timeouts and
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aging and removing routing table entries.
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The `Network code' contains routines which may run in the context of
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the user application tasks, the interface receive task or the network task.
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A network semaphore ensures that
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the data structures manipulated by the network code remain consistent.
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