From: Devarshi G. <dgh...@um...> - 2010-07-06 19:34:08
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Hi, I am running my C program using dmtcp_checkpoint(), but still dmtcpIsEnabled() returns false. Can you please send an example implementing the programming interface. On Mon, Jul 5, 2010 at 8:31 PM, Kapil Arya <ka...@cc...> wrote: > Hello Devarshi, > > In most cases, the restarted process will get a new PID. DMTCP virtualizes > the PIDs and TIDs and hence there is no need for the process to get the same > pid. There is a rare possible coincidence when the restarted process can get > the same PID -- when the PIDs get wrapped around and the next available PID > to be allocated to the restarted process is the same as its original one; > but as I mentioned, its a rare coincidence. > > The restarted and the original process can definitely exist at the same > time, but you will need to start a *new* dmtcp_coordinator for the restarted > process. The reason for this is that DMTCP gives each process a unique-id > which remains the same through the checkpoint-restart cycles and thus if > there are two processes with the same unique-id (parent and restarted) and > they both connect to the same dmtcp_coordinator, it won't work. > > However, if you start an extra dmtcp_coordinator, then both processes will > be talking to two different dmtcp_coordinators and hence there won't be any > issues. Of-course, you need to take care of any conflict of resources > between the restarted and the original process. > > Please let us know if you have any more questions. > > Thanks, > -Kapil > > On Mon, Jul 5, 2010 at 3:33 PM, Devarshi Ghoshal <dgh...@um...>wrote: > >> Hi, >> >> I am working with DMTCP for one of my projects and have a few questions >> related to it: >> i) Is there any way that the restarted process gets a new PID? >> ii) If that's the case, can the restarted process and the parent process >> be executed at the same time? >> >> Actually I tried to execute the main process and checkpointed segment at >> the same time but the coordinator doesn't allow because of the existing >> peers. Am I doing something wrong or is this not supported by DMTCP? >> >> -- >> Thanks & regards, >> Devarshi >> >> >> ------------------------------------------------------------------------------ >> This SF.net email is sponsored by Sprint >> What will you do first with EVO, the first 4G phone? >> Visit sprint.com/first -- http://p.sf.net/sfu/sprint-com-first >> _______________________________________________ >> Dmtcp-forum mailing list >> Dmt...@li... >> https://lists.sourceforge.net/lists/listinfo/dmtcp-forum >> >> > -- Thanks & regards, Devarshi |