Here is an updated webrev: http://cr.openjdk.java.net/~sla/8008102/webrev.01/
This uses the code from linux (adapted to the OS X API:s) to call ptrace and make sure we are stopped by the right signal. Thanks, /Staffan On 14 feb 2013, at 13:04, Staffan Larsen <staffan.lar...@oracle.com> wrote: > > 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 >>> >
