On 14 feb 2013, at 11:40, David Holmes <david.hol...@oracle.com> wrote:
> On 14/02/2013 1:05 AM, Staffan Larsen wrote: >> Please review the following change. >> >> When SA attaches to a JVM on OS X, it does not stop the process. If the JVM >> keeps running while SA inspects it can lead to all kinds of inconsistencies >> in SA. The proposed solution uses ptrace to attach to the process to keep it >> from running. Ptrace works a little bit differently on OS X, than on linux. >> For example, there is no need to attach to all threads, just attaching to >> the main process is enough. Additionally, the race that was recently found >> on linux [1] does not seem to be present on OS X (or at least I have not >> been able to reproduce it), so I have omitted that code. > > I would question how you can know for certain that the signal race [1] can > not happen on OSX? Would it not be prudent (and lend itself to future code > sharing) to follow the same approach as now used on Linux? I did not say I was certain, merely that I have not been able to reproduce it. I think there are big differences in how ptrace is implemented on Linux and OS X that explains why I don't see the same race. Anyway, you are right that we should be prudent and employ the same technique on OS X. New webrev coming. > I kind of dismayed that the OSX SA support has been found to be in such poor > shape. Makes me wonder what else in that port is lacking robustness. So do I... /Staffan > > David > >> webrev: http://cr.openjdk.java.net/~sla/8008102/webrev.00/ >> >> Thanks, >> /Staffan >> >> [1] >> http://mail.openjdk.java.net/pipermail/serviceability-dev/2013-February/008432.html >>
