Ralph,Thanks for your concern regarding the level of compliance of our implementation of the MPI standard. I don't know who were the MPI gurus you talked with about this issue, but I can tell that for once the MPI standard is pretty clear about this.
As stated by Aurelien in his last email, using the plural in several sentences, strongly suggest that the status of port should not be implicitly modified by MPI_Comm_accept or MPI_Comm_connect. Moreover, in the beginning of the chapter in the MPI standard, it is specified that comm/accept work exactly as in TCP. In other words, once the port is opened it stay open until the user explicitly close it.
However, not all corner cases are addressed by the MPI standard. What happens on MPI_Finalize ... it's a good question. Personally, I think we should stick with the TCP similarities. The port should be not only closed by unpublished. This will solve all issues with people trying to lookup a port once the originator is gone.
george. On Apr 25, 2008, at 5:25 PM, Ralph Castain wrote:
As I said, it makes no difference to me. I just want to ensure that everyoneagrees on the interpretation of the MPI standard. We have had thesediscussion in the past, with differing views. My guess here is that the port was left open mostly because the person who wrote the C-binding forgot toclose it. ;-)So, you MPI folks: do we allow multiple connections against a single port, and leave the port open until explicitly closed? If so, then do we generate an error if someone calls MPI_Finalize without first closing the port? Or dowe automatically close any open ports when finalize is called?Or do we automatically close the port after the connect/accept is completed?Thanks RalphOn 4/25/08 3:13 PM, "Aurélien Bouteiller" <boute...@eecs.utk.edu> wrote:Actually, the port was still left open forever before the change. The bug damaged the port string, and it was not usable anymore, not only in subsequent Comm_accept, but also in Close_port or Unpublish_name. To more specifically answer to your open port concern, if the user does not want to have an open port anymore, he should specifically call MPI_Close_port and not rely on MPI_Comm_accept to close it. Actually the standard suggests the exact contrary: section 5.4.2 states "it must call MPI_Open_port to establish a port [...] it must call MPI_Comm_accept to accept connections from clients". Becausethere is multiple clients AND multiple connections in that sentence, Iassume the port can be used in multiple accepts. Aurelien Le 25 avr. 08 à 16:53, Ralph Castain a écrit :Hmmm...just to clarify, this wasn't a "bug". It was my understanding per the MPI folks that a separate, unique port had to be created for every invocation of Comm_accept. They didn't want a port hanging around open, andtheir plan was to close the port immediately after the connection wasestablished. So dpm_orte was written to that specification. When I reorganized the code, I left the logic as it had been written - which was actually done by the MPI side of the house, not me. I have no problem with making the change. However, since the specification was created on the MPI side, I just want to make sure that the MPI folks all realize this has now been changed. Obviously, if this change in spec isadopted, someone needs to make sure that the C and Fortran bindings -do not- close that port any more! RalphOn 4/25/08 2:41 PM, "boute...@osl.iu.edu" <boute...@osl.iu.edu> wrote:Author: bouteill Date: 2008-04-25 16:41:44 EDT (Fri, 25 Apr 2008) New Revision: 18303 URL: https://svn.open-mpi.org/trac/ompi/changeset/18303 Log: Fix a bug that rpevented to use the same port (as returned by Open_port) for several Comm_accept) Text files modified: trunk/ompi/mca/dpm/orte/dpm_orte.c | 19 ++++++++++--------- 1 files changed, 10 insertions(+), 9 deletions(-) Modified: trunk/ompi/mca/dpm/orte/dpm_orte.c = = = = = = = = == = ===================================================================--- trunk/ompi/mca/dpm/orte/dpm_orte.c (original) +++ trunk/ompi/mca/dpm/orte/dpm_orte.c 2008-04-25 16:41:44 EDT (Fri, 25 Apr 2008) @@ -848,8 +848,14 @@ { char *tmp_string, *ptr; + /* copy the RML uri so we can return a malloc'd value + * that can later be free'd + */ + tmp_string = strdup(port_name); + /* find the ':' demarking the RML tag we added to the end */ - if (NULL == (ptr = strrchr(port_name, ':'))) { + if (NULL == (ptr = strrchr(tmp_string, ':'))) { + free(tmp_string); return NULL; } @@ -863,15 +869,10 @@ /* see if the length of the RML uri is too long - if so, * truncate it */ - if (strlen(port_name) > MPI_MAX_PORT_NAME) { - port_name[MPI_MAX_PORT_NAME] = '\0'; + if (strlen(tmp_string) > MPI_MAX_PORT_NAME) { + tmp_string[MPI_MAX_PORT_NAME] = '\0'; } - - /* copy the RML uri so we can return a malloc'd value - * that can later be free'd - */ - tmp_string = strdup(port_name); - + return tmp_string; } _______________________________________________ svn mailing list s...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/svn_______________________________________________ devel mailing list de...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/devel_______________________________________________ devel mailing list de...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/devel_______________________________________________ devel mailing list de...@open-mpi.org http://www.open-mpi.org/mailman/listinfo.cgi/devel
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