pvm_reg_hoster(3)

1REG_HOSTER(3PVM)                PVM Version 3.4               REG_HOSTER(3PVM)
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NAME

6       pvm_reg_hoster - Register task as PVM slave starter.
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SYNOPSIS

10       C    #include <pvmsdpro.h>
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12            int cc = pvm_reg_hoster()
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14       Fortran   Not Available
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DESCRIPTION

18       Registers  the calling task as a PVM slave pvmd starter.  When the mas‐
19       ter pvmd receives a DM_ADD message, instead of starting the  new  slave
20       pvmd  processes  itself,  it passes a message to the hoster, which does
21       the dirty work and sends a message back to the pvmd.
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23       Note:  This function isn't for beginners.  If you don't  grok  what  it
24       does,  you  probably don't need it.  For a more complete explanation of
25       what's going on here, you should refer to the PVM  source  code  and/or
26       user  guide  section  on implementation; this is just a man page.  That
27       said...
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29       When the master pvmd receives a DM_ADD message (request to add hosts to
30       the  virtual  machine),  it  looks  up  the new host IP addresses, gets
31       parameters from the host file if it was  started  with  one,  and  sets
32       default  parameters.   It  then  either attempts to start the processes
33       (using rsh or rexec()) or, if a  hoster  has  registered,  sends  it  a
34       SM_STHOST message.
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36       The format of the SM_STHOST message is:
37           int nhosts                // number of hosts
38           {
39               int tid               // of host
40               string options        // from hostfile so= field
41               string login          // in form ``[username@]hostname.domain''
42               string command        // to run on remote host
43           } [nhosts]
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45       The  hoster  should attempt to run each command on each host and record
46       the result.  A command usually looks like:
47           $PVM_ROOT/lib/pvmd  -s  -d8   -nhonk   1   80a9ca95:0f5a   4096   3
48       80a95c43:0000
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50       and a reply from a slave pvmd like:
51           ddpro<2312> arch<ALPHA> ip<80a95c43:0b3f> mtu<4096>
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53       When  finished,  the  hoster should send a SM_STHOSTACK message back to
54       the address of the sender (the master pvmd).  The format of  the  reply
55       message is:
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57           {
58               int tid               // of host, must match request
59               string status         // result line from slave or error code
60           } []                      // implied count
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62       The  TIDs in the reply must match those in the request.  They may be in
63       a different order, however.
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65       The result string should contain the entire reply (a single line)  from
66       each  new  slave pvmd, or an error code if something went wrong.  Legal
67       error codes are the literal names of the pvm_errno codes,  for  example
68       ``PvmCantStart''.  The default PVM hoster can return PvmDSysErr or Pvm‐
69       CantStart, and the slave pvmd itself can return PvmDupHost.
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71       The hoster must use pvm_setmwid() to set the wait ID in the reply  mes‐
72       sage  to  the same value as in the request.  The wait ID in the request
73       is obtained by calling pvm_getmwid().
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75       The hoster task must use pvm_setopt(PvmResvTids, 1)  to  allow  sending
76       reserved messages.  Messages should be packed using encoding PvmDataDe‐
77       fault to ensure they can be unpacked anywhere in the system.
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79       pvm_reg_hoster() returns PvmOk when successful.
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NAME

SYNOPSIS

DESCRIPTION

SEE ALSO