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diff --git a/docs/tutorials/016/combine.shar b/docs/tutorials/016/combine.shar deleted file mode 100644 index ec4a311e54a..00000000000 --- a/docs/tutorials/016/combine.shar +++ /dev/null @@ -1,385 +0,0 @@ -#!/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 2000-03-19 15:00 EST by <jcej@chiroptera.tragus.org>. -# Source directory was `/home/jcej/projects/ACE_wrappers/docs/tutorials/016'. -# -# Existing files will *not* be overwritten unless `-c' is specified. -# -# This shar contains: -# length mode name -# ------ ---------- ------------------------------------------ -# 422 -rw-rw-r-- hdr -# 51 -rw-rw-r-- bodies -# 2905 -rw-rw-r-- page01.pre -# 1349 -rw-rw-r-- page02.pre -# 247 -rw-rw-r-- page03.pre -# 310 -rw-rw-r-- page04.pre -# 606 -rw-rw-r-- page05.pre -# -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 _sh00306; 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' && -<HTML> -<HEAD> -X <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"> -X <META NAME="Author" CONTENT="James CE Johnson"> -X <TITLE>ACE Tutorial 016</TITLE> -</HEAD> -<BODY TEXT="#000000" BGCOLOR="#FFFFFF" LINK="#000FFF" VLINK="#FF0F0F"> -X -<CENTER><B><FONT SIZE=+2>ACE Tutorial 016</FONT></B></CENTER> -X -<CENTER><B><FONT SIZE=+2>Making ACE_Condition easier to use</FONT></B></CENTER> -X -<P> -<HR WIDTH="100%"> -SHAR_EOF - $shar_touch -am 03191459100 '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 \ - || $echo 'hdr:' 'MD5 check failed' -34600093c989939b7a2a6806f2b18f22 hdr -SHAR_EOF - else - shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'hdr'`" - test 422 -eq "$shar_count" || - $echo 'hdr:' 'original size' '422,' 'current size' "$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 -Condition_i.h -Condition_i.cpp -condition.cpp -SHAR_EOF - $shar_touch -am 1029153398 '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 \ - || $echo 'bodies:' 'MD5 check failed' -53b96616ae101b38fd1e30b2ab8707a2 bodies -SHAR_EOF - else - shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'bodies'`" - test 51 -eq "$shar_count" || - $echo 'bodies:' 'original size' '51,' 'current size' "$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' && -The ACE framework has quite a few objects for syncronizing your -threads and even processes. We've mentioned a few in passing already: -X ACE_Thread_Mutex and ACE_Barrier for instance. -<P> -Another interesting one is the ACE_Condition template. By using an -ACE_Condition you can have your code wait for an arbitrary condition -to occur. That condition is "embodied" in a variable of your choice. -That variable can, in turn, be any data type you wish. This makes -ACE_Condition much more flexible than a simple mutex, barrier or -semaphore. -<P> -In this tutorial, I'll create a wrapper class around the ACE_Condition -and the assorted housekeeping items necessary to make it work. I'll -use a simple integer as the condition variable but keep in mind that -you can use any data type you want. -<P> -Kirthika's abstract: -<ul> -An ACE_Condition class is a synchronisation mechanism employed in -situations where one or more threads cannot access the shared resource -unless some 'condition' becomes true. The ACE_Condition is associated -with a Mutex-lock which is released before blocking internally in the -wait call. Once the blocked thread is signaled to wake up again it -internally re-acquires the lock before checking the condition. -Unless the condition is true and it has the lock, it cant go ahead. -Once the shared resource is freed, a signal is sent to the waiting -threads which can now contend for the lock and access the resource. -<P> -Pizza-delivery metaphor: (courtesy Dr.Schmidt) -<ul> -Pizza delivery boy -- thread<br> -keys to delivery van -- mutex-lock<br> -pizza ready for delivery -- condition<br> -</Ul> -Situation: <br> -<ul> -Five pizza delivery boys use the same van. While the van is -unavailable, the boys go to sleep. When the van returns and the keys -are returned, the current user of the van nudges the other sleeping boys -to wake up and fight for the keys. Once the keys are obtained and the -pizza -is ready and out of the kitchen, the boy with the pizza and the keys can -now deliver it. -</ul> -<P> -This tutorial makes use of a wrapper class around the ACE_Condition and -uses a integer value as the condition. The four kinds of condition -implemented -are: !=, >=, <=, == by using C++ operator overloading. Guards are used -within -the methods to make sure that the method is thread-safe. Once the thread -completes -its job, it broadcasts to the waiting on it. -<P> -An ACE_Task is used to stress test the various conditions. -A test object is created for each condition and the main thread waits -until the condition becomes true. For instance: <= condition: -Five threads are spwaned which in turn increment the condition -variable, which is initialised to 1 by 2. Remember that you are waiting -on -the <= condition. So once 3 threads have been thru it, the value becomes -6 -and the condition becomes true! -<P> -This simple example shows us how to program and use the Condition -variable for -synchronisation. -</ul> -SHAR_EOF - $shar_touch -am 03191459100 '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 \ - || $echo 'page01.pre:' 'MD5 check failed' -a6fd2e6607a2b96c93d8a829a1fb53cc page01.pre -SHAR_EOF - else - shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page01.pre'`" - test 2905 -eq "$shar_count" || - $echo 'page01.pre:' 'original size' '2905,' 'current size' "$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 the declaration of the wrapper class. -<P> -The way you use ACE_Condition is something like this: -<UL> -<LI>First, the setup... -<UL> -<LI>Create a variable using your choice of data types -<LI>Create a mutex that will provide thread-safe access to that -variable -<LI>Create an ACE_Condition that uses the mutex -</UL> -<P> -<LI>Waiting for the condition... -<UL> -<PRE> -the_mutex.acquire(); -while( the_variable != some_desired_state_or_value ) -X the_condition.wait(); -the_mutex.release(); -</PRE> -Note that when <i>the_condition</i> is created, it must be given a -reference to the mutex. That's because the wait() method will release -the mutex before waiting and reacquire it after being signaled. -</UL> -<P> -<LI>Setting the condition... -<UL> -<PRE> -the_mutex.acquire(); -the_variable = some_new_value_or_state; -the_condition.signal() <i>OR</i> the_condition.broadcast() -</pre> -</UL> -</UL> -<P> -The problem I have is remembering to setup everything and co-ordinate -the locking, waiting and signaling. Even if I remember it all -correctly it just makes my application code more complex than it -should be. -<P> -To help out with that, I've created the class below to encapsulate the -three elements necessary for the condition to work. I've then added -methods for manipulation of the condition variable and waiting for the -condition to occur. -<HR> -SHAR_EOF - $shar_touch -am 03191459100 '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 \ - || $echo 'page02.pre:' 'MD5 check failed' -6c1b6e8f9597666558619d52c87be915 page02.pre -SHAR_EOF - else - shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page02.pre'`" - test 1349 -eq "$shar_count" || - $echo 'page02.pre:' 'original size' '1349,' 'current size' "$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' && -Ok, now we'll take a look at the definition of the class. You already -know how to use an ACE_Condition & it's not really that difficult. -Still, imagine how much more cluttered your code would be if it had to -include the mess I've got below! -<HR> -SHAR_EOF - $shar_touch -am 03191459100 '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 \ - || $echo 'page03.pre:' 'MD5 check failed' -bdf2bed6845300288a14d1a41f6ef8a6 page03.pre -SHAR_EOF - else - shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page03.pre'`" - test 247 -eq "$shar_count" || - $echo 'page03.pre:' 'original size' '247,' 'current size' "$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' && -We finally get to the main() application. I create a simple Task -derivative that will serve as a baseclass for other objects that test -specific functions of the Condition class. Notice how easy it is to -integrate a Condition into the application without keeping track of -three related member variables. -<HR> -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 \ - || $echo 'page04.pre:' 'MD5 check failed' -a2b2c42216f88e006a18d37adcb31c1d page04.pre -SHAR_EOF - else - shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page04.pre'`" - test 310 -eq "$shar_count" || - $echo 'page04.pre:' 'original size' '310,' 'current size' "$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' && -And that's all... -<P> -For general use, it would make sense to convert Condition into a -template and get rid of some of the operators that don't make sense. -Using an integer as the condition type probably isn't realistic since -you could just use a semaphore or barrier for that case. Still, the -Tutorial shows the basics and provides a foundation on which you can -create a more useful class for your application. -<P> -<UL> -<LI><A HREF="Condition_i.h">Condition_i.h</A> -<LI><A HREF="Condition_i.cpp">Condition_i.cpp</A> -<LI><A HREF="condition.cpp">condition.cpp</A> -<LI><A HREF="Makefile">Makefile</A> -</UL> -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 \ - || $echo 'page05.pre:' 'MD5 check failed' -3926547773016bf56d809fae9170625e page05.pre -SHAR_EOF - else - shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'page05.pre'`" - test 606 -eq "$shar_count" || - $echo 'page05.pre:' 'original size' '606,' 'current size' "$shar_count!" - fi -fi -rm -fr _sh00306 -exit 0 |