Walnut/Distributed Programming - Revision history

http://50.77.162.165/mediawiki/index.php?action=history&feed=atom&title=Walnut%2FDistributed_Programming Walnut/Distributed Programming - Revision history 2026-04-24T15:54:20Z Revision history for this page on the wiki MediaWiki 1.15.5-7 http://50.77.162.165/mediawiki/index.php?title=Walnut/Distributed_Programming&diff=1504&oldid=prev Mscheffler at 17:45, 26 November 2006 2006-11-26T17:45:54Z

<p></p> <p><b>New page</b></p><div></div>

Mscheffler http://50.77.162.165/mediawiki/index.php?title=Walnut/Distributed_Programming&diff=2460&oldid=prev Mscheffler: /* Data Lock */ 2006-11-26T17:39:05Z

<p><span class="autocomment">Data Lock</span></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">←Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 17:39, 26 November 2006</td> </tr> <tr><td colspan="2" class="diff-lineno">Line 816:</td> <td colspan="2" class="diff-lineno">Line 816:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>At the time of this writing, data lock has been seen only once in the wild. In that instance, a widely used object (call it WUO),contained one piece of mutable state and one piece of immutable state. The object that computed new versions of WUO's mutable state needed the immutable part of the state, and requested the current version of WUO from the owner of the object. Unfortunately, the owner knew that a new version was under construction, and was only sending out promises for WUO until the update was resolved. The solution in this case was to refactor WUO. This resulted in an architecture that was cleaner even by normal object design criteria, without regard to the distributed usage behavior. Insufficient data is yet available to assess how commonly this type of solution will suffice.</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>At the time of this writing, data lock has been seen only once in the wild. In that instance, a widely used object (call it WUO),contained one piece of mutable state and one piece of immutable state. The object that computed new versions of WUO's mutable state needed the immutable part of the state, and requested the current version of WUO from the owner of the object. Unfortunately, the owner knew that a new version was under construction, and was only sending out promises for WUO until the update was resolved. The solution in this case was to refactor WUO. This resulted in an architecture that was cleaner even by normal object design criteria, without regard to the distributed usage behavior. Insufficient data is yet available to assess how commonly this type of solution will suffice.</div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins style="color: red; font-weight: bold; text-decoration: none;">Next Section: [[Walnut/Secure_Distributed_Computing|Secure Distributed Computing]]</ins></div></td></tr>  </table>

Mscheffler http://50.77.162.165/mediawiki/index.php?title=Walnut/Distributed_Programming&diff=2459&oldid=prev Mscheffler: /* Example: minChat version 1 */ 2006-11-26T17:37:36Z

<p><span class="autocomment">Example: minChat version 1</span></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">←Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 17:37, 26 November 2006</td> </tr> <tr><td colspan="2" class="diff-lineno">Line 487:</td> <td colspan="2" class="diff-lineno">Line 487:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div><pre></div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div><pre></div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>  <<del class="diffchange diffchange-inline">nowiki>#?? in new vat minChatVat.e-swt</</del>nowiki></div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>  <nowiki></div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div><del class="diffchange diffchange-inline"></pre><pre></del></div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div><ins class="diffchange diffchange-inline"> #?? in new vat minChatVat.e-swt</ins></div></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div> </div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>  ## E sample</div></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>  <del class="diffchange diffchange-inline"><nowiki></del>## E sample</div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div></div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>  #!/usr/bin/env rune</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>  #!/usr/bin/env rune</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>  #eChat with minimalist user interface</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>  #eChat with minimalist user interface</div></td></tr>  </table>

Mscheffler http://50.77.162.165/mediawiki/index.php?title=Walnut/Distributed_Programming&diff=2458&oldid=prev Mscheffler: /* Letting When-Catch make a Promise For You */ 2006-11-26T17:32:54Z

<p><span class="autocomment">Letting When-Catch make a Promise For You</span></p> <table style="background-color: white; color:black;"> <col class='diff-marker' /> <col class='diff-content' /> <col class='diff-marker' /> <col class='diff-content' /> <tr valign='top'> <td colspan='2' style="background-color: white; color:black;">←Older revision</td> <td colspan='2' style="background-color: white; color:black;">Revision as of 17:32, 26 November 2006</td> </tr> <tr><td colspan="2" class="diff-lineno">Line 282:</td> <td colspan="2" class="diff-lineno">Line 282:</td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>===Letting When-Catch make a Promise For You===</div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div>===Letting When-Catch make a Promise For You===</div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'>-</td><td style="background: #ffa; color:black; font-size: smaller;"><div>As noted in chapter 1 under the Secret Lives of Flow Control Structures, control structures return values. When used as described up to this point, the return value of the when--catch expression has been ignored. In fact, the when-catch expression returns a promise for the value that the done function will return. If the done function does not return a value, then it will always resolve to null. However, if the <font color="#FF0000">done(value) function</font> of the when-catch returns a value, the when-catch returns a promise that will be fulfilled by the last value in the executed clause. Rewriting the calcMilesBeforeEmptyVow using this feature, we get: <span class="warn">not right, not right, fix</span></div></td><td class='diff-marker'>+</td><td style="background: #cfc; color:black; font-size: smaller;"><div>As noted in chapter 1 under the Secret Lives of Flow Control Structures, control structures return values. When used as described up to this point, the return value of the when--catch expression has been ignored. In fact, the when-catch expression returns a promise for the value that the done function will return. If the done function does not return a value, then it will always resolve to null. However, if the <font color="#FF0000">done(value) function</font> of the when-catch returns a value, the when-catch returns a promise that will be fulfilled by the last value in the executed clause. Rewriting the calcMilesBeforeEmptyVow using this feature, we get: <span class="warn<ins class="diffchange diffchange-inline">" style="color:red</ins>">not right, not right, fix</span></div></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"></td></tr> <tr><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div><pre></div></td><td class='diff-marker'> </td><td style="background: #eee; color:black; font-size: smaller;"><div><pre></div></td></tr>  </table>

Mscheffler http://50.77.162.165/mediawiki/index.php?title=Walnut/Distributed_Programming&diff=2457&oldid=prev Mscheffler at 16:59, 26 November 2006 2006-11-26T16:59:30Z

<p></p> <a href="http://50.77.162.165/mediawiki/index.php?title=Walnut/Distributed_Programming&diff=2457&oldid=1504">Show changes</a>

Mscheffler