<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">I still have one more question regarding the registration. I see that the following code prevents the factories for getting registered multiple time:<div><br></div><div><div><br></div><div>static bool MetaImageIOFactoryHasBeenRegistered;</div><div><br></div><div>void MetaImageIOFactoryRegister__Private(void)</div><div>{</div><div> if( ! MetaImageIOFactoryHasBeenRegistered )</div><div> {</div><div> MetaImageIOFactoryHasBeenRegistered = true;</div><div> MetaImageIOFactory::RegisterOneFactory();</div><div> }</div><div>}</div><div><br></div><div>I don't under stand how MetaImageIOFactoryHasBeenRegistered gets initialized before usage. And then is the static initialization fiasco [1] an issue?</div><div><br></div><div>[1] <a href="http://www.parashift.com/c++-faq-lite/ctors.html#faq-10.15">http://www.parashift.com/c++-faq-lite/ctors.html#faq-10.15</a></div><div><br></div><div><br></div><div>Thanks,</div><div>Brad</div><div><br></div><div><br></div><div><br><div><div>On Apr 12, 2012, at 11:06 AM, Lowekamp, Bradley (NIH/NLM/LHC) [C] wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Thanks for the information!<div><br></div><div>I clearly need to brush up on when different types of globals and static variables get initialized.</div><div><br></div><div>Brad<div><br><div><div>On Apr 12, 2012, at 10:22 AM, Brad King wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>On 4/12/2012 9:56 AM, Bradley Lowekamp wrote:<br><blockquote type="cite">the ImageIO Factories are registered by static initialization<br></blockquote><blockquote type="cite">in each translation unit which includes tikImageFileReader.h.<br></blockquote><br>That's correct, but only for translation units in applications.<br><br>This is the only solution I've found that preserves the pre-<br>modularization registration behavior without requiring every<br>application to *explicitly* call an init function. The app<br>must do the init because after modularization the base classes<br>cannot magically know about all their implementations in other<br>modules. The solution is to inject static initalization into<br>translation units of applications.<br><br><blockquote type="cite">C++ does not specify the thread safety of static initialization.<br></blockquote><br>By the time main() runs to start threads other than the main one<br>the static initialization will have completed. The concern should<br>only exist for dynamically loaded libraries (plugins). For those<br>an application developer can compile with the option that says<br>not to do the auto init magic. Just add<br><br> set(ITK_NO_IO_FACTORY_REGISTER_MANAGER 1)<br><br>before including ITK in the application CMake code.<br><br>-Brad K<br></div></blockquote></div><br><div>
<div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; font-size: 12px; "><span class="Apple-style-span" style="border-collapse: separate; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; -webkit-text-decorations-in-effect: none; text-indent: 0px; -webkit-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">========================================================</font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">Bradley Lowekamp<span class="Apple-converted-space"> </span><span class="Apple-converted-space"> </span></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">Medical Science and Computing for</font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">Office of High Performance Computing and Communications</font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">National Library of Medicine<span class="Apple-converted-space"> </span></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; "><a href="mailto:blowekamp@mail.nih.gov">blowekamp@mail.nih.gov</a></font></div><br class="Apple-interchange-newline"></span></div><br class="Apple-interchange-newline">
</div>
<br></div></div></div>_______________________________________________<br>Powered by <a href="http://www.kitware.com">www.kitware.com</a><br><br>Visit other Kitware open-source projects at<br><a href="http://www.kitware.com/opensource/opensource.html">http://www.kitware.com/opensource/opensource.html</a><br><br>Kitware offers ITK Training Courses, for more information visit:<br>http://kitware.com/products/protraining.php<br><br>Please keep messages on-topic and check the ITK FAQ at:<br>http://www.itk.org/Wiki/ITK_FAQ<br><br>Follow this link to subscribe/unsubscribe:<br>http://www.itk.org/mailman/listinfo/insight-developers<br></blockquote></div><br><div>
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><span class="Apple-style-span" style="border-collapse: separate; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; -webkit-text-decorations-in-effect: none; text-indent: 0px; -webkit-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; -webkit-text-decorations-in-effect: none; text-indent: 0px; -webkit-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">========================================================</font></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">Bradley Lowekamp<span class="Apple-converted-space"> </span><span class="Apple-converted-space"> </span></font></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">Medical Science and Computing for</font></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">Office of High Performance Computing and Communications</font></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">National Library of Medicine<span class="Apple-converted-space"> </span></font></p><p style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; "><a href="mailto:blowekamp@mail.nih.gov">blowekamp@mail.nih.gov</a></font></p><br class="Apple-interchange-newline"></span></div></span></span><br class="Apple-interchange-newline">
</div>
<br></div></div></body></html>