#!/bin/sh # This is a shell archive (produced by GNU sharutils 4.2). # To extract the files from this archive, save it to some FILE, remove # everything before the `!/bin/sh' line above, then type `sh FILE'. # # Made on 1999-09-21 22:49 EDT by . # Source directory was `/home/jcej/projects/ACE_wrappers/docs/tutorials/011'. # # Existing files will *not* be overwritten unless `-c' is specified. # # This shar contains: # length mode name # ------ ---------- ------------------------------------------ # 442 -rw-rw-r-- hdr # 48 -rw-rw-r-- bodies # 869 -rw-rw-r-- page01.pre # 164 -rw-rw-r-- page02.pre # 174 -rw-rw-r-- page03.pre # 127 -rw-rw-r-- page04.pre # 2691 -rw-rw-r-- page05.pre # 707 -rw-rw-r-- page06.pre # 351 -rw-rw-r-- page02.pst # 366 -rw-rw-r-- page03.pst # 129 -rw-rw-r-- page04.pst # save_IFS="${IFS}" IFS="${IFS}:" gettext_dir=FAILED locale_dir=FAILED first_param="$1" for dir in $PATH do if test "$gettext_dir" = FAILED && test -f $dir/gettext \ && ($dir/gettext --version >/dev/null 2>&1) then set `$dir/gettext --version 2>&1` if test "$3" = GNU then gettext_dir=$dir fi fi if test "$locale_dir" = FAILED && test -f $dir/shar \ && ($dir/shar --print-text-domain-dir >/dev/null 2>&1) then locale_dir=`$dir/shar --print-text-domain-dir` fi done IFS="$save_IFS" if test "$locale_dir" = FAILED || test "$gettext_dir" = FAILED then echo=echo else TEXTDOMAINDIR=$locale_dir export TEXTDOMAINDIR TEXTDOMAIN=sharutils export TEXTDOMAIN echo="$gettext_dir/gettext -s" fi touch -am 1231235999 $$.touch >/dev/null 2>&1 if test ! -f 1231235999 && test -f $$.touch; then shar_touch=touch else shar_touch=: echo $echo 'WARNING: not restoring timestamps. Consider getting and' $echo "installing GNU \`touch', distributed in GNU File Utilities..." echo fi rm -f 1231235999 $$.touch # if mkdir _sh04967; then $echo 'x -' 'creating lock directory' else $echo 'failed to create lock directory' exit 1 fi # ============= hdr ============== if test -f 'hdr' && test "$first_param" != -c; then $echo 'x -' SKIPPING 'hdr' '(file already exists)' else $echo 'x -' extracting 'hdr' '(text)' sed 's/^X//' << 'SHAR_EOF' > 'hdr' && X X X ACE Tutorial 011 X
ACE Tutorial 011
X
Passing non-trivial data through an ACE_Message_Queue
X X

SHAR_EOF $shar_touch -am 0124154699 'hdr' && chmod 0664 'hdr' || $echo 'restore of' 'hdr' '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 \ || $echo 'hdr:' 'MD5 check failed' cf10a170c9ca8512b7051526e2dcf83c hdr SHAR_EOF else shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'hdr'`" test 442 -eq "$shar_count" || $echo 'hdr:' 'original size' '442,' 'current size' "$shar_count!" fi fi # ============= bodies ============== if test -f 'bodies' && test "$first_param" != -c; then $echo 'x -' SKIPPING 'bodies' '(file already exists)' else $echo 'x -' extracting 'bodies' '(text)' sed 's/^X//' << 'SHAR_EOF' > 'bodies' && PAGE=2 message_queue.cpp task.h task.cpp data.h SHAR_EOF $shar_touch -am 0124155199 'bodies' && chmod 0664 'bodies' || $echo 'restore of' 'bodies' '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 \ || $echo 'bodies:' 'MD5 check failed' db3ba3829b49952c833adb921acd3d3f bodies SHAR_EOF else shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'bodies'`" test 48 -eq "$shar_count" || $echo 'bodies:' 'original size' '48,' 'current size' "$shar_count!" fi fi # ============= page01.pre ============== if test -f 'page01.pre' && test "$first_param" != -c; then $echo 'x -' SKIPPING 'page01.pre' '(file already exists)' else $echo 'x -' extracting 'page01.pre' '(text)' sed 's/^X//' << 'SHAR_EOF' > 'page01.pre' &&

In the previous tutorial we learned how to put text into a message queue. While that may be useful, it isn't very exciting or realistic. In most cases you'll need to move complex data structures between your threads.

In this tutorial I'll expand the previous by moving not only a text string but also a more complex object. In the next tutorial I'll change things again so that we move the complex object a bit more efficiently.

A simple abstract for a simple tutorial:

(Abstract by Kirthika, as always.) SHAR_EOF $shar_touch -am 0126201399 'page01.pre' && chmod 0664 'page01.pre' || $echo 'restore of' 'page01.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 \ || $echo 'page01.pre:' 'MD5 check failed' 58768929bbe513a9fa2302b1fe3170be page01.pre SHAR_EOF else shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page01.pre'`" test 869 -eq "$shar_count" || $echo 'page01.pre:' 'original size' '869,' 'current size' "$shar_count!" fi fi # ============= page02.pre ============== if test -f 'page02.pre' && test "$first_param" != -c; then $echo 'x -' SKIPPING 'page02.pre' '(file already exists)' else $echo 'x -' extracting 'page02.pre' '(text)' sed 's/^X//' << 'SHAR_EOF' > 'page02.pre' && We'll look first at main(). A large part of this is the same as before, so I've only commented the changes.

X

SHAR_EOF $shar_touch -am 0124154699 'page02.pre' && chmod 0664 'page02.pre' || $echo 'restore of' 'page02.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 \ || $echo 'page02.pre:' 'MD5 check failed' ccd60d44cf4f9730aa16ff042f324c8e page02.pre SHAR_EOF else shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page02.pre'`" test 164 -eq "$shar_count" || $echo 'page02.pre:' 'original size' '164,' 'current size' "$shar_count!" fi fi # ============= page03.pre ============== if test -f 'page03.pre' && test "$first_param" != -c; then $echo 'x -' SKIPPING 'page03.pre' '(file already exists)' else $echo 'x -' extracting 'page03.pre' '(text)' sed 's/^X//' << 'SHAR_EOF' > 'page03.pre' && X Our Task object declaration and definition. X As with message_queue.cpp, I've only commented the changes.

X

SHAR_EOF $shar_touch -am 0124155099 'page03.pre' && chmod 0664 'page03.pre' || $echo 'restore of' 'page03.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 \ || $echo 'page03.pre:' 'MD5 check failed' e99896d191834752e7e07317af06ea0c page03.pre SHAR_EOF else shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page03.pre'`" test 174 -eq "$shar_count" || $echo 'page03.pre:' 'original size' '174,' 'current size' "$shar_count!" fi fi # ============= page04.pre ============== if test -f 'page04.pre' && test "$first_param" != -c; then $echo 'x -' SKIPPING 'page04.pre' '(file already exists)' else $echo 'x -' extracting 'page04.pre' '(text)' sed 's/^X//' << 'SHAR_EOF' > 'page04.pre' && X Before we go further, let's look at this Data object that's causing all the fuss. X

SHAR_EOF $shar_touch -am 0124154699 '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 \ || $echo 'page04.pre:' 'MD5 check failed' 4fe23822fef63921fa81cbf97e25bd5e page04.pre SHAR_EOF else shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page04.pre'`" test 127 -eq "$shar_count" || $echo 'page04.pre:' 'original size' '127,' 'current size' "$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 Let's take a look at this new program's output: X 

[jcej@chiroptera 011]$./message_queue 4 2
(12108|1024) Task ctor 0xbffff9c8
(12108|2050) Task 0xbffff9c8 starts in thread 2050
(12108|1025) Task 0xbffff9c8 starts in thread 1025
(12108|1024) DataBase ctor 0xbffff9c0
(12108|1024) Data ctor 0xbffff9c0 for message 0
(12108|1024) Block ctor 0x8052d08
(12108|1024) Data dtor 0xbffff9c0
(12108|1024) DataBase dtor 0xbffff9c0
(12108|1024) DataBase ctor 0xbffff9c0
(12108|1024) Data ctor 0xbffff9c0 for message 1
(12108|1024) Block ctor 0x8052e00
(12108|1024) Data dtor 0xbffff9c0
(12108|1024) DataBase dtor 0xbffff9c0
(12108|1024) DataBase ctor 0xbffff9c0
(12108|1024) Data ctor 0xbffff9c0 for message 2
(12108|1024) Block ctor 0x8052ef8
(12108|1024) Data dtor 0xbffff9c0
(12108|1024) DataBase dtor 0xbffff9c0
(12108|1024) DataBase ctor 0xbffff9c0
(12108|1024) Data ctor 0xbffff9c0 for message 3
(12108|1024) Block ctor 0x8052ff0
(12108|1024) Data dtor 0xbffff9c0
(12108|1024) DataBase dtor 0xbffff9c0
(12108|1024) Block ctor 0x80530e8
(12108|1025) Block 0x8052d08 contains (This is message 0.)
(12108|1025) DataBase ctor 0xbf9ffe20
(12108|1025) Data ctor 0xbf9ffe20
(12108|1025) DataBase instance 0xbf9ffe20
(12108|1025) I am a Data object for message 0
(12108|1025) Block dtor 0x8052d08
(12108|1025) Data dtor 0xbf9ffe20
(12108|1025) DataBase dtor 0xbf9ffe20
(12108|1025) Block 0x8052e00 contains (This is message 1.)
(12108|1025) DataBase ctor 0xbf9ffe20
(12108|1025) Data ctor 0xbf9ffe20
(12108|1025) DataBase instance 0xbf9ffe20
(12108|1025) I am a Data object for message 1
(12108|1025) Block dtor 0x8052e00
(12108|1025) Data dtor 0xbf9ffe20
(12108|1025) DataBase dtor 0xbf9ffe20
(12108|1025) Block 0x8052ef8 contains (This is message 2.)
(12108|1025) DataBase ctor 0xbf9ffe20
(12108|1025) Data ctor 0xbf9ffe20
(12108|1025) DataBase instance 0xbf9ffe20
(12108|1025) I am a Data object for message 2
(12108|1025) Block dtor 0x8052ef8
(12108|1025) Data dtor 0xbf9ffe20
(12108|1025) DataBase dtor 0xbf9ffe20
(12108|1025) Block 0x8052ff0 contains (This is message 3.)
(12108|1025) DataBase ctor 0xbf9ffe20
(12108|1025) Data ctor 0xbf9ffe20
(12108|1025) DataBase instance 0xbf9ffe20
(12108|1025) I am a Data object for message 3
(12108|2050) Task close 0xbffff9c8
(12108|1025) Block dtor 0x8052ff0
(12108|1025) Data dtor 0xbf9ffe20
(12108|1025) DataBase dtor 0xbf9ffe20
(12108|1025) Task close 0xbffff9c8
(12108|1024) Task dtor 0xbffff9c8
(12108|1024) Block dtor 0x80530e8
(12108|1024) Application exiting
[jcej@chiroptera 011]$

Other than being more verbose because of the Data object, this shows us the same thing we've seen before.

SHAR_EOF $shar_touch -am 0124154699 '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 \ || $echo 'page05.pre:' 'MD5 check failed' b95ed571240b8383db0e0c0b07d04971 page05.pre SHAR_EOF else shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page05.pre'`" test 2691 -eq "$shar_count" || $echo 'page05.pre:' 'original size' '2691,' 'current size' "$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' && So, this time we stuffed an object into the message queue instead of just text data. Each time required two object constructions (and subsequent destructions) and two "deep" copy operations on the object. There might actually be times when this is OK for your application but I prefer to keep those things down to a minimum. In the next tutorial I'll show you a way to do that.

X

X * data.h hasn't changed at all from Tutorial 7 so I didn't devote a X page to it. SHAR_EOF $shar_touch -am 0124155399 '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 \ || $echo 'page06.pre:' 'MD5 check failed' 17d64bbe275773a80d7d767e04e0474c page06.pre SHAR_EOF else shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page06.pre'`" test 707 -eq "$shar_count" || $echo 'page06.pre:' 'original size' '707,' 'current size' "$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' &&

The new trick here is the use of copy() to copy our abstract data object into the message block memory. Notice that it's OK to let the Data object go out of scope at that point since we've got a separate copy. If you've got something with a non-trivial ctor/dtor then this won't work. We'll address that in the next tutorial. SHAR_EOF $shar_touch -am 0124154699 '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 \ || $echo 'page02.pst:' 'MD5 check failed' 89fa13e74842bc65092e0e6f61fdd889 page02.pst SHAR_EOF else shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page02.pst'`" test 351 -eq "$shar_count" || $echo 'page02.pst:' 'original size' '351,' 'current size' "$shar_count!" fi fi # ============= page03.pst ============== if test -f 'page03.pst' && test "$first_param" != -c; then $echo 'x -' SKIPPING 'page03.pst' '(file already exists)' else $echo 'x -' extracting 'page03.pst' '(text)' sed 's/^X//' << 'SHAR_EOF' > 'page03.pst' &&

Notice how we had to create a temporary Data object to copy the stuff out of the message block? Again, if there were non-trivial ctor/dtors involved then this wouldn't work at all.

Again, like Tutorial 10 we've skipped THR_DETACHED because we wait() for the threads to exit X elsewhere. SHAR_EOF $shar_touch -am 0921223499 'page03.pst' && chmod 0664 'page03.pst' || $echo 'restore of' 'page03.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 \ || $echo 'page03.pst:' 'MD5 check failed' ae1320ae6609c684317a5895f69bf47d page03.pst SHAR_EOF else shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page03.pst'`" test 366 -eq "$shar_count" || $echo 'page03.pst:' 'original size' '366,' 'current size' "$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' &&

Ok, no mysterious magic on this one. Just a simple object and derivative that report their existence.

SHAR_EOF $shar_touch -am 0124154699 '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 \ || $echo 'page04.pst:' 'MD5 check failed' 777ab8789fb82b1e280b9e127983c4b0 page04.pst SHAR_EOF else shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page04.pst'`" test 129 -eq "$shar_count" || $echo 'page04.pst:' 'original size' '129,' 'current size' "$shar_count!" fi fi rm -fr _sh04967 exit 0