combine.shar

这是广泛使用的通信开源项目,对于大容量,高并发的通讯要求完全能够胜任,他广泛可用于网络游戏医学图像网关的高qos要求.更详细的内容可阅读相应的材料

duplicate() method of the message block (or blocks) to get a new
message block referencing the same data block.  This is very efficient
since the actual data is not copied.
<P>
<HR WIDTH="100%">
SHAR_EOF
  $shar_touch -am 03191459100 'page04.pre' &&
  chmod 0664 'page04.pre' ||
  $echo 'restore of' 'page04.pre' 'failed'
  if ( md5sum --help 2>&1 | grep 'sage: md5sum \[' ) >/dev/null 2>&1 \
  && ( md5sum --version 2>&1 | grep -v 'textutils 1.12' ) >/dev/null; then
    md5sum -c << SHAR_EOF >/dev/null 2>&1 \
    || $echo 'page04.pre:' 'MD5 check failed'
c8b4750a824380f2effc43557c8540ad  page04.pre
SHAR_EOF
  else
    shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page04.pre'`"
    test 1048 -eq "$shar_count" ||
    $echo 'page04.pre:' 'original size' '1048,' 'current size' "$shar_count!"
  fi
fi
# ============= page05.pre ==============
if test -f 'page05.pre' && test "$first_param" != -c; then
  $echo 'x -' SKIPPING 'page05.pre' '(file already exists)'
else
  $echo 'x -' extracting 'page05.pre' '(text)'
  sed 's/^X//' << 'SHAR_EOF' > 'page05.pre' &&
X
X
<P>
<HR WIDTH="100%">
<P>
On this page we have the code for the Data_Block and Message_Block
objects.  As you probably suspect from the header on the previous
page, the complicated part is in the construction and destruction of
the Data_Block.
<P>
<HR WIDTH="100%">
SHAR_EOF
  $shar_touch -am 03191459100 'page05.pre' &&
  chmod 0664 'page05.pre' ||
  $echo 'restore of' 'page05.pre' 'failed'
  if ( md5sum --help 2>&1 | grep 'sage: md5sum \[' ) >/dev/null 2>&1 \
  && ( md5sum --version 2>&1 | grep -v 'textutils 1.12' ) >/dev/null; then
    md5sum -c << SHAR_EOF >/dev/null 2>&1 \
    || $echo 'page05.pre:' 'MD5 check failed'
a95fdcd3db2356b091228728f4f3f130  page05.pre
SHAR_EOF
  else
    shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page05.pre'`"
    test 268 -eq "$shar_count" ||
    $echo 'page05.pre:' 'original size' '268,' 'current size' "$shar_count!"
  fi
fi
# ============= page06.pre ==============
if test -f 'page06.pre' && test "$first_param" != -c; then
  $echo 'x -' SKIPPING 'page06.pre' '(file already exists)'
else
  $echo 'x -' extracting 'page06.pre' '(text)'
  sed 's/^X//' << 'SHAR_EOF' > 'page06.pre' &&
X
X
<P>
<HR WIDTH="100%">
<P>
Let's take a look now at the new Task object.  This will obviously be
different from the Tasks we've created before but I think you'll be
surprised at how relatively simple it actually is.
<P>
Remember that the goal of this tutorial was to use the reference
counting abilities of the ACE_Data_Block.  The only way to show that
effectively is to have a data block passed between different threads.
A thread pool isn't really going to do that so, instead, our new Task
can be part of a chain of tasks.  In that way, each Task can pass the
data on to another and satisfy our need for moving the ACE_Data_Block
around.
If we've done the reference counting correctly then none of our tasks
will be trying to work with deleted data and we won't have any memory
leaks at the end.
<P>
There's not much to the header, so I've included it and the cpp file
on this one page.
<P>
<HR WIDTH="100%">
SHAR_EOF
  $shar_touch -am 03191459100 'page06.pre' &&
  chmod 0664 'page06.pre' ||
  $echo 'restore of' 'page06.pre' 'failed'
  if ( md5sum --help 2>&1 | grep 'sage: md5sum \[' ) >/dev/null 2>&1 \
  && ( md5sum --version 2>&1 | grep -v 'textutils 1.12' ) >/dev/null; then
    md5sum -c << SHAR_EOF >/dev/null 2>&1 \
    || $echo 'page06.pre:' 'MD5 check failed'
a4c9b50df3240c5134733d2033fd5f03  page06.pre
SHAR_EOF
  else
    shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page06.pre'`"
    test 914 -eq "$shar_count" ||
    $echo 'page06.pre:' 'original size' '914,' 'current size' "$shar_count!"
  fi
fi
# ============= page07.pre ==============
if test -f 'page07.pre' && test "$first_param" != -c; then
  $echo 'x -' SKIPPING 'page07.pre' '(file already exists)'
else
  $echo 'x -' extracting 'page07.pre' '(text)'
  sed 's/^X//' << 'SHAR_EOF' > 'page07.pre' &&
X
X
<P>
<HR WIDTH="100%">
<P>
I've been trying to justify the chain of tasks by talking about a
Work object that implements a state machine.  The idea is that your
Work object has to perform a series of discrete steps to complete it's
function.  Traditionally, all of those steps would take place in one
thread of execution.  That thread would probably be one from a Task
thread pool.
<P>
Suppose, however, that some of those steps spend a lot of time waiting
for disk IO.  You could find that all of your thread-pool threads
are just sitting there waiting for the disk.  You might then be
tempted to increase the thread pool size to get more work through.
However, if some of the stages are memory intensive, you could run out
of memory if all of the workers get to that state at the same time.
<P>
One solution might be to have different thread pools for each state.
Each pool could have it's size tuned appropriately for the work that
would be done there.  That's where the chain of Tasks comes in.
X In this tutorial's implementation I've taken the
easy route and set all of the thread pools to the same size but a more
realistic solution would be to set each thread pool in the chain to a
specific size as needed by that state of operation.
<P>
There's not much to this header either so I've combined it with the
cpp file as with task.
<P>
<HR WIDTH="100%">
SHAR_EOF
  $shar_touch -am 03191459100 'page07.pre' &&
  chmod 0664 'page07.pre' ||
  $echo 'restore of' 'page07.pre' 'failed'
  if ( md5sum --help 2>&1 | grep 'sage: md5sum \[' ) >/dev/null 2>&1 \
  && ( md5sum --version 2>&1 | grep -v 'textutils 1.12' ) >/dev/null; then
    md5sum -c << SHAR_EOF >/dev/null 2>&1 \
    || $echo 'page07.pre:' 'MD5 check failed'
17c1c426089b288e418c3f62fdc09744  page07.pre
SHAR_EOF
  else
    shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page07.pre'`"
    test 1360 -eq "$shar_count" ||
    $echo 'page07.pre:' 'original size' '1360,' 'current size' "$shar_count!"
  fi
fi
# ============= page08.pre ==============
if test -f 'page08.pre' && test "$first_param" != -c; then
  $echo 'x -' SKIPPING 'page08.pre' '(file already exists)'
else
  $echo 'x -' extracting 'page08.pre' '(text)'
  sed 's/^X//' << 'SHAR_EOF' > 'page08.pre' &&
X
X
<P>
<HR WIDTH="100%">
<P>
And that's the end of another tutorial.  This one is probably the most
complicated so far because I've introduced or expanded upon
a number of different
concepts.  Namely:  state machines, reference counting and task
chaining.  I hope I didn't complicate things to the point where the
lesson got lost in the noise.  As always, feel free to drop a note to
the ACE-Users mailing list if you feel that some of this could use a
little more explaination.
X
<P>
<UL>
<LI><A HREF="Makefile">Makefile</A>
<LI><A HREF="block.cpp">block.cpp</A>
<LI><A HREF="block.h">block.h</A>
<LI><A HREF="message_queue.cpp">message_queue.cpp</A>
<LI><A HREF="mld.cpp">mld.cpp</A>
<LI><A HREF="mld.h">mld.h</A>
<LI><A HREF="task.cpp">task.cpp</A>
<LI><A HREF="task.h">task.h</A>
<LI><A HREF="work.cpp">work.cpp</A>
<LI><A HREF="work.h">work.h</A>
</UL>
<P>
SHAR_EOF
  $shar_touch -am 03191459100 'page08.pre' &&
  chmod 0664 'page08.pre' ||
  $echo 'restore of' 'page08.pre' 'failed'
  if ( md5sum --help 2>&1 | grep 'sage: md5sum \[' ) >/dev/null 2>&1 \
  && ( md5sum --version 2>&1 | grep -v 'textutils 1.12' ) >/dev/null; then
    md5sum -c << SHAR_EOF >/dev/null 2>&1 \
    || $echo 'page08.pre:' 'MD5 check failed'
b761e40eff75cbf3174b53b4b0c5c172  page08.pre
SHAR_EOF
  else
    shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page08.pre'`"
    test 860 -eq "$shar_count" ||
    $echo 'page08.pre:' 'original size' '860,' 'current size' "$shar_count!"
  fi
fi
# ============= page02.pst ==============
if test -f 'page02.pst' && test "$first_param" != -c; then
  $echo 'x -' SKIPPING 'page02.pst' '(file already exists)'
else
  $echo 'x -' extracting 'page02.pst' '(text)'
  sed 's/^X//' << 'SHAR_EOF' > 'page02.pst' &&
<HR WIDTH="100%">
<P>
Nothing really surprising here...  Just remember that your total
number of threads is ( ( 1 + subtasks ) * threads ).  You probably
don't want to get too carried away with that!
<P>
SHAR_EOF
  $shar_touch -am 03191459100 'page02.pst' &&
  chmod 0664 'page02.pst' ||
  $echo 'restore of' 'page02.pst' 'failed'
  if ( md5sum --help 2>&1 | grep 'sage: md5sum \[' ) >/dev/null 2>&1 \
  && ( md5sum --version 2>&1 | grep -v 'textutils 1.12' ) >/dev/null; then
    md5sum -c << SHAR_EOF >/dev/null 2>&1 \
    || $echo 'page02.pst:' 'MD5 check failed'
a8c43c5c68518f6eb8c03701d1603a92  page02.pst
SHAR_EOF
  else
    shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page02.pst'`"
    test 204 -eq "$shar_count" ||
    $echo 'page02.pst:' 'original size' '204,' 'current size' "$shar_count!"
  fi
fi
# ============= page04.pst ==============
if test -f 'page04.pst' && test "$first_param" != -c; then
  $echo 'x -' SKIPPING 'page04.pst' '(file already exists)'
else
  $echo 'x -' extracting 'page04.pst' '(text)'
  sed 's/^X//' << 'SHAR_EOF' > 'page04.pst' &&
<HR WIDTH="100%">
<P>
One of the most difficult parts of this to get right was the Lock
object.  I didn't even have it in the beginning but I soon realized
that the reference counts were getting weird.  A little careful
reading of the comments and the source informed me that some sort of
locking is necessary to keep the counter sane.  The simplest thing at
that point was to use the ACE_Lock_Adaptor&lt;&gt; to adapt ACE_Mutex
appropriately.  The next trick was to ensure that the lock object was
destroyed at the proper time to prevent both memory leaks and core
dumps.  The finaly product may be a little bit intimidating at first
but it's really quite simple once you understand the motivation.
<P>
SHAR_EOF
  $shar_touch -am 03191459100 'page04.pst' &&
  chmod 0664 'page04.pst' ||
  $echo 'restore of' 'page04.pst' 'failed'
  if ( md5sum --help 2>&1 | grep 'sage: md5sum \[' ) >/dev/null 2>&1 \
  && ( md5sum --version 2>&1 | grep -v 'textutils 1.12' ) >/dev/null; then
    md5sum -c << SHAR_EOF >/dev/null 2>&1 \
    || $echo 'page04.pst:' 'MD5 check failed'
325565f3f72961b842b612caeb93b36a  page04.pst
SHAR_EOF
  else
    shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page04.pst'`"
    test 704 -eq "$shar_count" ||
    $echo 'page04.pst:' 'original size' '704,' 'current size' "$shar_count!"
  fi
fi
# ============= page06.pst ==============
if test -f 'page06.pst' && test "$first_param" != -c; then
  $echo 'x -' SKIPPING 'page06.pst' '(file already exists)'
else
  $echo 'x -' extracting 'page06.pst' '(text)'
  sed 's/^X//' << 'SHAR_EOF' > 'page06.pst' &&
<HR WIDTH="100%">
<P>
So you see... it wasn't really that much more complicated.  We really
just have to remember to pass to <i>next_</i> when we finish working
on the data.  If your Unit_Of_Work derivative is going to implement a
state machine be sure that you also implement a fini() method
<em>or</em> ensure that your chain of subtasks is large enough for all
possible states.
<P>
SHAR_EOF
  $shar_touch -am 03191459100 'page06.pst' &&
  chmod 0664 'page06.pst' ||
  $echo 'restore of' 'page06.pst' 'failed'
  if ( md5sum --help 2>&1 | grep 'sage: md5sum \[' ) >/dev/null 2>&1 \
  && ( md5sum --version 2>&1 | grep -v 'textutils 1.12' ) >/dev/null; then
    md5sum -c << SHAR_EOF >/dev/null 2>&1 \
    || $echo 'page06.pst:' 'MD5 check failed'
65a1b8bc21034187e0885cc07fa7734f  page06.pst
SHAR_EOF
  else
    shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page06.pst'`"
    test 385 -eq "$shar_count" ||
    $echo 'page06.pst:' 'original size' '385,' 'current size' "$shar_count!"
  fi
fi
# ============= page07.pst ==============
if test -f 'page07.pst' && test "$first_param" != -c; then
  $echo 'x -' SKIPPING 'page07.pst' '(file already exists)'
else
  $echo 'x -' extracting 'page07.pst' '(text)'
  sed 's/^X//' << 'SHAR_EOF' > 'page07.pst' &&
<HR>
<P>
And that is that.  For a more complex machine that may want to "jump
states" you would have to set some "state information" (sorry, bad
choice of terminology again) so that process() could decide what to do
at each call.  You might also modify Task::svc() so that it will
respect the return value of process() and do something useful with the
information.
<P>
SHAR_EOF
  $shar_touch -am 03191459100 'page07.pst' &&
  chmod 0664 'page07.pst' ||
  $echo 'restore of' 'page07.pst' 'failed'
  if ( md5sum --help 2>&1 | grep 'sage: md5sum \[' ) >/dev/null 2>&1 \
  && ( md5sum --version 2>&1 | grep -v 'textutils 1.12' ) >/dev/null; then
    md5sum -c << SHAR_EOF >/dev/null 2>&1 \
    || $echo 'page07.pst:' 'MD5 check failed'
21f1bb3615bd4ba5efe5ec25bb895c0e  page07.pst
SHAR_EOF
  else
    shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page07.pst'`"
    test 369 -eq "$shar_count" ||
    $echo 'page07.pst:' 'original size' '369,' 'current size' "$shar_count!"
  fi
fi
rm -fr _sh32654
exit 0