You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@stdcxx.apache.org by "Liviu Nicoara (JIRA)" <ji...@apache.org> on 2012/10/10 13:55:05 UTC
[jira] [Commented] (STDCXX-1072) [Oracle Solaris/SPARCV8] stricter
mutex alignment requirements
[ https://issues.apache.org/jira/browse/STDCXX-1072?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13473163#comment-13473163 ]
Liviu Nicoara commented on STDCXX-1072:
---------------------------------------
The attached patch.2.diff uses the aligned buffer class for a cleaner and slightly more verbose fix.
> [Oracle Solaris/SPARCV8] stricter mutex alignment requirements
> --------------------------------------------------------------
>
> Key: STDCXX-1072
> URL: https://issues.apache.org/jira/browse/STDCXX-1072
> Project: C++ Standard Library
> Issue Type: Bug
> Components: Thread Safety
> Affects Versions: 4.2.1, 4.2.x, 4.3.x, 5.0.0
> Environment: Oracle Solaris on SPARC V8 (or V9 emulation?) hardware.
> Reporter: Liviu Nicoara
> Assignee: Liviu Nicoara
> Labels: SPARC, Solaris, V8, alignment, mutex
> Fix For: 4.2.x, 4.3.x, 5.0.0
>
> Attachments: patch.2.diff, patch.diff
>
> Original Estimate: 4h
> Remaining Estimate: 4h
>
> The issue has been reported in STDCXX-1040, then STDCXX-1066. The originator was apparently an improvement (as a response to CR 6296770: http://tinyurl.com/8ohjsgl) shipped with KU 137111-01 (http://tinyurl.com/ceet6ec) which requires stricter alignment than the machine word for userland mutexes.
> Quoting here the Fujitsu patch notes (in case it goes away):
> {quote}
> {noformat}
> 2) When an application using the mutex lock or rw lock in the way shown below is executed. (*1, *2) ...
> *2) ... example of programming that causes the ... problem.
> <In the case where the problem occurs>
> ----------------------------------------------------------------
> int *ip;
> mutex_t *mp;
> ip = (int *) malloc(sizeof (int) + sizeof (mutex_t));
> mp = (mutex_t *) (ip + 1);
> /* The address is used with a modification */
> ----------------------------------------------------------------
> <In the case where the problem does not occur -1>
> ----------------------------------------------------------------
> mutex_t mp; /* Obtained statically */
> ----------------------------------------------------------------
> <In the case where the problem does not occur -2>
> ----------------------------------------------------------------
> mutex_t *mp;
> mp = (mutex_t *) malloc(sizeof (mutex_t));
> /* The address is used without any modifications */
> ----------------------------------------------------------------
> {noformat}
> {quote}
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira