Forum OpenACS Development: Re: Fatal Signal 11 Upon Startup of Naviserver on OS X

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6: Re: Fatal Signal 11 Upon Startup of Naviserver on OS X (response to 5)
Posted by Gustaf Neumann on 01/15/16 09:10 AM
Setting "connsperthread" in the config file is not necessary, the default is a reasonable value. However, the crash is very strange, i use naviserver since many years on a daily basis on Mac Mac OS X notebook. Can you send me the config file causing the crash? What are the versions of Mac OS X and naviserver where this happens?
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7: Re: Fatal Signal 11 Upon Startup of Naviserver on OS X (response to 6)
Posted by Gustaf Neumann on 01/15/16 11:28 AM
I have a suspicion: the ns_set used for the configure variables is implemented mutex-lock-free, developed probably under the assumption that only the main thead reads modifies config data during startup. Since the "connsperthread" is read/written back during the startup there can be a race condition.

This would explain the situation, since it depends on the configuration, speed of the machine, .... i will look into this deeper, probably at the weekend.

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8: Re: Fatal Signal 11 Upon Startup of Naviserver on OS X (response to 6)
Posted by Gustaf Neumann on 01/17/16 07:38 PM
I've looked deeper into this issue. I am pretty sure that there is/was a race condition in the code. The only occurrence of this type of problem is indeed the setting of "connsperthread", therefore leaving the default value for this parameter solves this issue.

The issue is already part of NaviServer 4.99.0 (released July 2005). There is now a fix for this in the tip version in bitbucket, which will be included in the next release of NaviServer.

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9: Re: Fatal Signal 11 Upon Startup of Naviserver on OS X (response to 8)
Posted by Dave Bauer on 01/17/16 07:55 PM
Thanks, Gustaf, for all your help.