chl.c

Path MPICH-V for MPICH the MPI Implementation

#include "chl.h"

#include <unistd.h>
#include "debug.h"

/**
 * Fork and executes the exeargv array according the restart/invoke flag, for this rang and this job id
 * The localMPI argument is already pushed on the stack.
 * @param argv: the array of arguments ([0] is the path)
 * @param argc: the number of used arguments
 * @param args: the size of the argv array
 * @param wid: the group number of the application
 * @param rankid: the rank of the MPI process
 * @param invoke: not zero iff this is not a restart
 * @return the pid of the new process or -1 in case of error
 */
int ckptForkExec(char **argv, int argc, int args, int wid, int rankid, int invoke)
{
  char *p;
  char *exepath;
  char *exename;
  int pid;

  if( !invoke )
    {
      printw("No checkpoint enabled: can not restart a process");
      return -1;
    }

  pid = fork();
  if(pid == -1)
    {
      printe("fork() for the MPI process");
      return -1;
    }

  if( pid > 0 )
    return pid;

  exepath = argv[0];
  exename = exepath;
  for(p = exepath; *p; p++)
    if( *p == '/' ) exename = p+1;
  argv[0] = exename;

#ifdef DEBUG
  {
    char **param;
    char *cmdline;
    int cmdsize = strlen(exepath) + 128;
    for(param = argv; *param; param++)
      cmdsize += strlen(*param) + 1;
    cmdline = (char*)malloc(cmdsize);
    cmdline[0] = 0;
    for(param = argv; *param; param++)
      {
	strcat(cmdline, *param);
	strcat(cmdline, " ");
      }
    printi("param", "vdaemon: executing %s [%s]", exepath, cmdline);
    free(cmdline);
  }
#endif
  
  execvp(exepath, argv);
  qerror("vdaemon execvp(%s)", argv[0]);
  return -1;
}