Example #1
0
/* ------------------------------------------------------------------------------------ */
static int gasnetc_attach_primary(void) {
  int retval = GASNET_OK;

  AMLOCK();
    /* pause to make sure all nodes have called attach 
       if a node calls gasnet_exit() between init/attach, then this allows us
       to process the AMUDP_SPMD control messages required for job shutdown
     */
    gasnetc_bootstrapBarrier();

    /* ------------------------------------------------------------------------------------ */
    /*  register fatal signal handlers */

    /* catch fatal signals and convert to SIGQUIT */
    gasneti_registerSignalHandlers(gasneti_defaultSignalHandler);

#if HAVE_ON_EXIT
    on_exit(gasnetc_on_exit, NULL);
#else
    atexit(gasnetc_atexit);
#endif

    #if GASNET_TRACE || GASNET_DEBUG
     #if !GASNET_DEBUG
      if (GASNETI_TRACE_ENABLED(A))
     #endif
        GASNETI_AM_SAFE(AMUDP_SetHandlerCallbacks(gasnetc_endpoint,
          gasnetc_enteringHandler_hook, gasnetc_leavingHandler_hook));
    #endif

    #if GASNETC_MOCK_EVERYTHING
      retval = AM_SetSeg(gasnetc_endpoint, NULL, (uintptr_t)-1);
      if (retval != AM_OK) INITERR(RESOURCE, "AM_SetSeg() failed");
    #endif

    /* ------------------------------------------------------------------------------------ */
    /*  primary attach complete */
    gasneti_attach_done = 1;
    gasnetc_bootstrapBarrier();
  AMUNLOCK();

  GASNETI_TRACE_PRINTF(C,("gasnetc_attach_primary(): primary attach complete\n"));

  gasnete_init(); /* init the extended API */

  gasneti_nodemapFini();

  /* ensure extended API is initialized across nodes */
  AMLOCK();
    gasnetc_bootstrapBarrier();
  AMUNLOCK();

  gasneti_assert(retval == GASNET_OK);
  return retval;

done: /*  error return while locked */
  AMUNLOCK();
  GASNETI_RETURN(retval);
}
Example #2
0
extern int gasnetc_AMPoll(void) {
  int retval;
  GASNETI_CHECKATTACH();
#if GASNET_PSHM
  gasneti_AMPSHMPoll(0);
#endif
  AMLOCK();
    GASNETI_AM_SAFE_NORETURN(retval,AM_Poll(gasnetc_bundle));
  AMUNLOCK();
  if_pf (retval) GASNETI_RETURN_ERR(RESOURCE);
  else return GASNET_OK;
Example #3
0
// TODO-EX: this is a candidate for factorization (once we understand the per-conduit variations)
extern int gasnetc_attach( gex_TM_t               _tm,
                           gasnet_handlerentry_t  *table,
                           int                    numentries,
                           uintptr_t              segsize)
{
  int retval = GASNET_OK;

  GASNETI_TRACE_PRINTF(C,("gasnetc_attach(table (%i entries), segsize=%"PRIuPTR")",
                          numentries, segsize));
  gasneti_TM_t tm = gasneti_import_tm(_tm);
  gasneti_EP_t ep = tm->_ep;

  if (!gasneti_init_done) 
    GASNETI_RETURN_ERRR(NOT_INIT, "GASNet attach called before init");
  if (gasneti_attach_done) 
    GASNETI_RETURN_ERRR(NOT_INIT, "GASNet already attached");

  /*  check argument sanity */
  #if GASNET_SEGMENT_FAST || GASNET_SEGMENT_LARGE
    if ((segsize % GASNET_PAGESIZE) != 0) 
      GASNETI_RETURN_ERRR(BAD_ARG, "segsize not page-aligned");
    if (segsize > gasneti_MaxLocalSegmentSize) 
      GASNETI_RETURN_ERRR(BAD_ARG, "segsize too large");
  #else
    segsize = 0;
  #endif

  /*  primary attach  */
  if (GASNET_OK != gasnetc_attach_primary())
    GASNETI_RETURN_ERRR(RESOURCE,"Error in primary attach");

  #if GASNET_SEGMENT_FAST || GASNET_SEGMENT_LARGE
    /*  register client segment  */
    gex_Segment_t seg; // g2ex segment is automatically saved by a hook
    if (GASNET_OK != gasnetc_attach_segment(&seg, _tm, segsize, gasneti_defaultExchange, GASNETI_FLAG_INIT_LEGACY))
      GASNETI_RETURN_ERRR(RESOURCE,"Error attaching segment");
  #endif

  AMLOCK();
    /*  register client handlers */
    if (table && gasneti_amregister_legacy(ep->_amtbl, table, numentries) != GASNET_OK)
      INITERR(RESOURCE,"Error registering handlers");
  AMUNLOCK();

  /* ensure everything is initialized across all nodes */
  gasnet_barrier(0, GASNET_BARRIERFLAG_UNNAMED);

  return GASNET_OK;

done: /*  error return while locked */
  AMUNLOCK();
  GASNETI_RETURN(retval);
}
Example #4
0
extern int gasnetc_AMPoll(GASNETI_THREAD_FARG_ALONE) {
  int retval;
  GASNETI_CHECKATTACH();
#if GASNET_PSHM
  gasneti_AMPSHMPoll(0 GASNETI_THREAD_PASS);
#endif
  AMLOCK();
  // In single-nbrhd case never need to poll the network for client AMs.
  // However, we'll still check for control traffic for orderly exit handling.
  if (gasneti_mysupernode.grp_count > 1) {
    GASNETI_AM_SAFE_NORETURN(retval,AM_Poll(gasnetc_bundle));
  } else {
    // TODO-EX: a lock-free peek would allow elimination of a lock cycle
    GASNETI_AM_SAFE_NORETURN(retval,AMUDP_SPMDHandleControlTraffic(NULL));
  }
  AMUNLOCK();
  if_pf (retval) GASNETI_RETURN_ERR(RESOURCE);
  else return GASNET_OK;
Example #5
0
/* ------------------------------------------------------------------------------------ */
extern int gasnetc_attach(gasnet_handlerentry_t *table, int numentries,
                          uintptr_t segsize, uintptr_t minheapoffset) {
  int retval = GASNET_OK;
  void *segbase = NULL;
  
  GASNETI_TRACE_PRINTF(C,("gasnetc_attach(table (%i entries), segsize=%lu, minheapoffset=%lu)",
                          numentries, (unsigned long)segsize, (unsigned long)minheapoffset));
  AMLOCK();
    if (!gasneti_init_done) 
      INITERR(NOT_INIT, "GASNet attach called before init");
    if (gasneti_attach_done) 
      INITERR(NOT_INIT, "GASNet already attached");

    /* pause to make sure all nodes have called attach 
       if a node calls gasnet_exit() between init/attach, then this allows us
       to process the AMUDP_SPMD control messages required for job shutdown
     */
    gasnetc_bootstrapBarrier();

    /*  check argument sanity */
    #if GASNET_SEGMENT_FAST || GASNET_SEGMENT_LARGE
      if ((segsize % GASNET_PAGESIZE) != 0) 
        INITERR(BAD_ARG, "segsize not page-aligned");
      if (segsize > gasneti_MaxLocalSegmentSize) 
        INITERR(BAD_ARG, "segsize too large");
      if ((minheapoffset % GASNET_PAGESIZE) != 0) /* round up the minheapoffset to page sz */
        minheapoffset = ((minheapoffset / GASNET_PAGESIZE) + 1) * GASNET_PAGESIZE;
    #else
      segsize = 0;
      minheapoffset = 0;
    #endif

    segsize = gasneti_auxseg_preattach(segsize); /* adjust segsize for auxseg reqts */

    /* ------------------------------------------------------------------------------------ */
    /*  register handlers */
#ifdef GASNETC_MAX_NUMHANDLERS
    /* Initialize shadow handler table */
    { int i;
      for (i=0; i<GASNETC_MAX_NUMHANDLERS; i++)
          gasnetc_handler[i]=(gasneti_handler_fn_t)&gasneti_defaultAMHandler;
    }
#endif
    { /*  core API handlers */
      gasnet_handlerentry_t *ctable = (gasnet_handlerentry_t *)gasnetc_get_handlertable();
      int len = 0;
      int numreg = 0;
      gasneti_assert(ctable);
      while (ctable[len].fnptr) len++; /* calc len */
      if (gasnetc_reghandlers(ctable, len, 1, 63, 0, &numreg) != GASNET_OK)
        INITERR(RESOURCE,"Error registering core API handlers");
      gasneti_assert(numreg == len);
    }

    { /*  extended API handlers */
      gasnet_handlerentry_t *etable = (gasnet_handlerentry_t *)gasnete_get_handlertable();
      int len = 0;
      int numreg = 0;
      gasneti_assert(etable);
      while (etable[len].fnptr) len++; /* calc len */
      if (gasnetc_reghandlers(etable, len, 64, 127, 0, &numreg) != GASNET_OK)
        INITERR(RESOURCE,"Error registering extended API handlers");
      gasneti_assert(numreg == len);
    }

    if (table) { /*  client handlers */
      int numreg1 = 0;
      int numreg2 = 0;

      /*  first pass - assign all fixed-index handlers */
      if (gasnetc_reghandlers(table, numentries, 128, 255, 0, &numreg1) != GASNET_OK)
        INITERR(RESOURCE,"Error registering fixed-index client handlers");

      /*  second pass - fill in dontcare-index handlers */
      if (gasnetc_reghandlers(table, numentries, 128, 255, 1, &numreg2) != GASNET_OK)
        INITERR(RESOURCE,"Error registering fixed-index client handlers");

      gasneti_assert(numreg1 + numreg2 == numentries);
    }

    /* ------------------------------------------------------------------------------------ */
    /*  register fatal signal handlers */

    /* catch fatal signals and convert to SIGQUIT */
    gasneti_registerSignalHandlers(gasneti_defaultSignalHandler);

#if HAVE_ON_EXIT
    on_exit(gasnetc_on_exit, NULL);
#else
    atexit(gasnetc_atexit);
#endif

    /* ------------------------------------------------------------------------------------ */
    /*  register segment  */

    gasneti_seginfo = (gasnet_seginfo_t *)gasneti_malloc(gasneti_nodes*sizeof(gasnet_seginfo_t));
    gasneti_leak(gasneti_seginfo);

    #if GASNET_SEGMENT_FAST || GASNET_SEGMENT_LARGE
      gasneti_segmentAttach(segsize, minheapoffset, gasneti_seginfo, &gasnetc_bootstrapExchange);
    #else /* GASNET_SEGMENT_EVERYTHING */
      { int i;
        for (i=0;i<gasneti_nodes;i++) {
          gasneti_seginfo[i].addr = (void *)0;
          gasneti_seginfo[i].size = (uintptr_t)-1;
        }
      }
    #endif
    segbase = gasneti_seginfo[gasneti_mynode].addr;
    segsize = gasneti_seginfo[gasneti_mynode].size;
  
    /* After local segment is attached, call optional client-provided hook
       (###) should call BEFORE any conduit-specific pinning/registration of the segment
     */
    if (gasnet_client_attach_hook) {
      gasnet_client_attach_hook(segbase, segsize);
    }

    /*  AMUDP allows arbitrary registration with no further action  */
    if (segsize) {
      retval = AM_SetSeg(gasnetc_endpoint, segbase, segsize);
      if (retval != AM_OK) INITERR(RESOURCE, "AM_SetSeg() failed");
    }

    #if GASNET_TRACE
      if (GASNETI_TRACE_ENABLED(A))
        GASNETI_AM_SAFE(AMUDP_SetHandlerCallbacks(gasnetc_endpoint,
          gasnetc_enteringHandler_hook, gasnetc_leavingHandler_hook));
    #endif

    /* ------------------------------------------------------------------------------------ */
    /*  primary attach complete */
    gasneti_attach_done = 1;
    gasnetc_bootstrapBarrier();
  AMUNLOCK();

  GASNETI_TRACE_PRINTF(C,("gasnetc_attach(): primary attach complete\n"));

  gasneti_auxseg_attach(); /* provide auxseg */

  gasnete_init(); /* init the extended API */

  gasneti_nodemapFini();

  /* ensure extended API is initialized across nodes */
  AMLOCK();
  gasnetc_bootstrapBarrier();
  AMUNLOCK();

  gasneti_assert(retval == GASNET_OK);
  return retval;

done: /*  error return while locked */
  AMUNLOCK();
  GASNETI_RETURN(retval);
}
Example #6
0
static int gasnetc_init(int *argc, char ***argv) {
  int retval = GASNET_OK;

  /*  check system sanity */
  gasnetc_check_config();

  /* --------- begin Master code ------------ */
  if (!AMUDP_SPMDIsWorker(argv?*argv:NULL)) {
    /* assume we're an implicit master 
       (we don't currently support explicit workers spawned 
        without using the AMUDP SPMD API)   
     */
    int num_nodes;
    int i;
    char spawnfn;
    amudp_spawnfn_t fp = (amudp_spawnfn_t)NULL;

    if (!argv) {
      gasneti_fatalerror("implicit-master without argv not supported - use amudprun");
    }

    /* pretend we're node 0, for purposes of verbose env reporting */
    gasneti_init_done = 1;
    gasneti_mynode = 0;

    #if defined(GASNET_CSPAWN_CMD)
    { /* set configure default cspawn cmd */
      const char *cmd = gasneti_getenv_withdefault("GASNET_CSPAWN_CMD",GASNET_CSPAWN_CMD);
      gasneti_setenv("GASNET_CSPAWN_CMD",cmd);
    }
    #endif

    /* parse node count from command line */
    if (*argc < 2) {
      fprintf(stderr, "GASNet: Missing parallel node count\n");
      fprintf(stderr, "GASNet: Specify node count as first argument, or use upcrun/tcrun spawner script to start job\n");
      fprintf(stderr, "GASNet: Usage '%s <num_nodes> {program arguments}'\n", (*argv)[0]);
      exit(-1);
    }
    /*
     * argv[1] is number of nodes; argv[0] is program name; argv is
     * list of arguments including program name and number of nodes.
     * We need to remove argv[1] when the argument array is passed
     * to the tic_main().
     */
    num_nodes = atoi((*argv)[1]);
    if (num_nodes < 1) {
      fprintf (stderr, "GASNet: Invalid number of nodes: %s\n", (*argv)[1]);
      fprintf (stderr, "GASNet: Usage '%s <num_nodes> {program arguments}'\n", (*argv)[0]);
      exit (1);
    }

    /* remove the num_nodes argument */
    for (i = 1; i < (*argc)-1; i++) {
      (*argv)[i] = (*argv)[i+1];
    }
    (*argv)[(*argc)-1] = NULL;
    (*argc)--;

    /* get spawnfn */
    spawnfn = *gasneti_getenv_withdefault("GASNET_SPAWNFN", _STRINGIFY(GASNETC_DEFAULT_SPAWNFN));

    { /* ensure we pass the effective spawnfn to worker env */
      char spawnstr[2];
      spawnstr[0] = toupper(spawnfn);
      spawnstr[1] = '\0';
      gasneti_setenv("GASNET_SPAWNFN",spawnstr);
    }

    /* ensure reliable localhost operation by forcing use of 127.0.0.1
     * setting GASNET_MASTERIP to the empty string will prevent this */
    if (('L' == toupper(spawnfn)) && !gasneti_getenv("GASNET_MASTERIP")) {
      gasneti_setenv("GASNET_MASTERIP","127.0.0.1");
    }

    for (i=0; AMUDP_Spawnfn_Desc[i].abbrev; i++) {
      if (toupper(spawnfn) == toupper(AMUDP_Spawnfn_Desc[i].abbrev)) {
        fp = AMUDP_Spawnfn_Desc[i].fnptr;
        break;
      }
    }

    if (!fp) {
      fprintf (stderr, "GASNet: Invalid spawn function specified in GASNET_SPAWNFN\n");
      fprintf (stderr, "GASNet: The following mechanisms are available:\n");
      for (i=0; AMUDP_Spawnfn_Desc[i].abbrev; i++) {
        fprintf(stderr, "    '%c'  %s\n",  
              toupper(AMUDP_Spawnfn_Desc[i].abbrev), AMUDP_Spawnfn_Desc[i].desc);
      }
      exit(1);
    }

    #if GASNET_DEBUG_VERBOSE
      /* note - can't call trace macros during gasnet_init because trace system not yet initialized */
      fprintf(stderr,"gasnetc_init(): about to spawn...\n"); fflush(stderr);
    #endif

    retval = AMUDP_SPMDStartup(argc, argv, 
      num_nodes, 0, fp,
      NULL, &gasnetc_bundle, &gasnetc_endpoint);
    /* master startup should never return */
    gasneti_fatalerror("master AMUDP_SPMDStartup() failed");
  }

  /* --------- begin Worker code ------------ */
  AMLOCK();
    if (gasneti_init_done) 
      INITERR(NOT_INIT, "GASNet already initialized");

    gasneti_freezeForDebugger();

    AMUDP_VerboseErrors = gasneti_VerboseErrors;
    AMUDP_SPMDkillmyprocess = gasneti_killmyprocess;

    /*  perform job spawn */
    retval = AMUDP_SPMDStartup(argc, argv, 
      0, 0, NULL, /* dummies */
      &gasnetc_networkpid, &gasnetc_bundle, &gasnetc_endpoint);
    if (retval != AM_OK) INITERR(RESOURCE, "slave AMUDP_SPMDStartup() failed");
    gasneti_init_done = 1; /* enable early to allow tracing */

    gasneti_conduit_getenv = (/* cast drops const */ gasneti_getenv_fn_t*)&AMUDP_SPMDgetenvMaster;
    gasneti_mynode = AMUDP_SPMDMyProc();
    gasneti_nodes = AMUDP_SPMDNumProcs();

    /* enable tracing */
    gasneti_trace_init(argc, argv);
    GASNETI_AM_SAFE(AMUDP_SPMDSetExitCallback(gasnetc_traceoutput));

    /* for local spawn, assume we want to wait-block */
    if (gasneti_getenv("GASNET_SPAWNFN") && *gasneti_getenv("GASNET_SPAWNFN") == 'L') { 
      GASNETI_TRACE_PRINTF(C,("setting gasnet_set_waitmode(GASNET_WAIT_BLOCK) for localhost spawn"));
      gasnet_set_waitmode(GASNET_WAIT_BLOCK);
    }

    #if GASNET_DEBUG_VERBOSE
      fprintf(stderr,"gasnetc_init(): spawn successful - node %i/%i starting...\n", 
        gasneti_mynode, gasneti_nodes); fflush(stderr);
    #endif

    gasneti_nodemapInit(&gasnetc_bootstrapExchange, NULL, 0, 0);

    #if GASNET_PSHM
      gasneti_pshm_init(&gasnetc_bootstrapSNodeBroadcast, 0);
    #endif

    #if GASNET_SEGMENT_FAST || GASNET_SEGMENT_LARGE
    { uintptr_t limit;
      #if HAVE_MMAP
        limit = gasneti_mmapLimit((uintptr_t)-1, (uint64_t)-1,
                                  &gasnetc_bootstrapExchange,
                                  &gasnetc_bootstrapBarrier);
      #else
        limit = (intptr_t)-1;
      #endif
      gasneti_segmentInit(limit, &gasnetc_bootstrapExchange);
    }
    #elif GASNET_SEGMENT_EVERYTHING
      /* segment is everything - nothing to do */
    #else
      #error Bad segment config
    #endif

    #if GASNET_BLCR
      gasneti_checkpoint_guid = gasnetc_networkpid;
      gasneti_checkpoint_init(NULL);
    #endif

  AMUNLOCK();

  gasneti_auxseg_init(); /* adjust max seg values based on auxseg */

  gasneti_assert(retval == GASNET_OK);
  return retval;

done: /*  error return while locked */
  AMUNLOCK();
  GASNETI_RETURN(retval);
}
Example #7
0
static int gasnetc_init(int *argc, char ***argv) {
  int retval = GASNET_OK;
  int networkdepth = 0;
  const char *pstr = NULL;
  const char *tmsgstr = NULL;

  AMLOCK();
    if (gasneti_init_done) 
      INITERR(NOT_INIT, "GASNet already initialized");
    gasneti_init_done = 1; /* enable early to allow tracing */

    /*  check system sanity */
    gasnetc_check_config();

    gasneti_freezeForDebugger();

    #if GASNET_DEBUG_VERBOSE
      /* note - can't call trace macros during gasnet_init because trace system not yet initialized */
      fprintf(stderr,"gasnetc_init(): about to spawn...\n"); fflush(stderr);
    #endif

    /*  choose network depth */
    networkdepth = gasnett_getenv_int_withdefault("GASNET_NETWORKDEPTH", GASNETC_DEFAULT_NETWORKDEPTH, 0);
    if (networkdepth <= 1) networkdepth = GASNETC_DEFAULT_NETWORKDEPTH;

    AMMPI_VerboseErrors = gasneti_VerboseErrors;
    AMMPI_SPMDkillmyprocess = gasneti_killmyprocess;
    #if !defined(GASNETI_DISABLE_MPI_INIT_THREAD) 
      { int res; 
      #if GASNETI_THREADS
        /* tell MPI to be thread-safe */
        res = AMMPI_SPMDSetThreadMode(1, &pstr, argc, argv);
      #else
        res = AMMPI_SPMDSetThreadMode(0, &pstr, argc, argv);
      #endif
        if (!res) { 
          #if GASNETI_THREADS
          { static char tmsg[255];
            snprintf(tmsg, sizeof(tmsg),
                          "*** WARNING: The pthreaded version of mpi-conduit requires an MPI implementation "
                          "which supports threading mode MPI_THREAD_SERIALIZED, "
                          "but this implementation reports it can only support %s\n", pstr);
            #if GASNET_DEBUG_VERBOSE
              /* only show this in verbose mode, because some versions of MPICH (eg Quadrics version)
                 lie and report THREAD_SINGLE, when in actuality MPI_THREAD_SERIALIZED works just fine */
              if (!gasneti_getenv_yesno_withdefault("GASNET_QUIET",0)) fprintf(stderr, "%s", tmsg);
            #else
              tmsgstr = tmsg;
            #endif
          }
          #else
            fprintf(stderr,"unknown failure in AMMPI_SPMDSetThreadMode() => %s\n",pstr);
          #endif
        }
      }
    #endif

    /*  perform job spawn */
    retval = AMMPI_SPMDStartup(argc, argv, networkdepth, NULL, &gasnetc_bundle, &gasnetc_endpoint);
    if (retval != AM_OK) INITERR(RESOURCE, "AMMPI_SPMDStartup() failed");

    gasneti_mynode = AMMPI_SPMDMyProc();
    gasneti_nodes = AMMPI_SPMDNumProcs();

    /* a number of MPI job spawners fail to propagate the environment to all compute nodes */
    /* do this before trace_init to make sure it gets right environment */
    gasneti_setupGlobalEnvironment(gasneti_nodes, gasneti_mynode, 
                                   gasnetc_bootstrapExchange, gasnetc_bootstrapBroadcast);

    /* enable tracing */
    gasneti_trace_init(argc, argv);
    GASNETI_AM_SAFE(AMMPI_SPMDSetExitCallback(gasnetc_traceoutput));
    if (pstr)    GASNETI_TRACE_PRINTF(C,("AMMPI_SPMDSetThreadMode/MPI_Init_thread()=>%s",pstr));
    if (tmsgstr) GASNETI_TRACE_PRINTF(I,("%s",tmsgstr));

    #if GASNET_DEBUG_VERBOSE
      fprintf(stderr,"gasnetc_init(): spawn successful - node %i/%i starting...\n", 
        gasneti_mynode, gasneti_nodes); fflush(stderr);
    #endif

    gasneti_nodemapInit(&gasnetc_bootstrapExchange, NULL, 0, 0);

    #if GASNET_PSHM
      gasneti_pshm_init(&gasnetc_bootstrapExchange, 0);
    #endif
 
    #if GASNET_SEGMENT_FAST || GASNET_SEGMENT_LARGE
    { uintptr_t limit;
      #if HAVE_MMAP
        limit = gasneti_mmapLimit((uintptr_t)-1, (uint64_t)-1,
                                  &gasnetc_bootstrapExchange,
                                  &gasnetc_bootstrapBarrier);
      #else
        limit = (intptr_t)-1;
      #endif
      gasneti_segmentInit(limit, &gasnetc_bootstrapExchange);
    }
    #elif GASNET_SEGMENT_EVERYTHING
      /* segment is everything - nothing to do */
    #else
      #error Bad segment config
    #endif

  AMUNLOCK();

  gasneti_auxseg_init(); /* adjust max seg values based on auxseg */

  gasneti_assert(retval == GASNET_OK);
  return retval;

done: /*  error return while locked */
  AMUNLOCK();
  GASNETI_RETURN(retval);
}
Example #8
0
static int gasnetc_init(int *argc, char ***argv, gex_Flags_t flags) {
  int retval = GASNET_OK;

  /*  check system sanity */
  gasnetc_check_config();

  /* --------- begin Master code ------------ */
  if (!AMUDP_SPMDIsWorker(argv?*argv:NULL)) {
    /* assume we're an implicit master 
       (we don't currently support explicit workers spawned 
        without using the AMUDP SPMD API)   
     */
    int num_nodes;
    int i;
    char spawnfn;
    amudp_spawnfn_t fp = (amudp_spawnfn_t)NULL;

    if (!argv) {
      gasneti_fatalerror("implicit-master without argv not supported - use amudprun");
    }

    /* pretend we're node 0, for purposes of verbose env reporting */
    gasneti_init_done = 1;
    gasneti_mynode = 0;

    #if defined(GASNET_CSPAWN_CMD)
    { /* set configure default cspawn cmd */
      const char *cmd = gasneti_getenv_withdefault("GASNET_CSPAWN_CMD",GASNET_CSPAWN_CMD);
      gasneti_setenv("GASNET_CSPAWN_CMD",cmd);
    }
    #endif

    /* parse node count from command line */
    if (*argc < 2) {
      fprintf(stderr, "GASNet: Missing parallel node count\n");
      fprintf(stderr, "GASNet: Specify node count as first argument, or use upcrun/tcrun spawner script to start job\n");
      fprintf(stderr, "GASNet: Usage '%s <num_nodes> {program arguments}'\n", (*argv)[0]);
      exit(-1);
    }
    /*
     * argv[1] is number of nodes; argv[0] is program name; argv is
     * list of arguments including program name and number of nodes.
     * We need to remove argv[1] when the argument array is passed
     * to the tic_main().
     */
    num_nodes = atoi((*argv)[1]);
    if (num_nodes < 1) {
      fprintf (stderr, "GASNet: Invalid number of nodes: %s\n", (*argv)[1]);
      fprintf (stderr, "GASNet: Usage '%s <num_nodes> {program arguments}'\n", (*argv)[0]);
      exit (1);
    }

    /* remove the num_nodes argument */
    for (i = 1; i < (*argc)-1; i++) {
      (*argv)[i] = (*argv)[i+1];
    }
    (*argv)[(*argc)-1] = NULL;
    (*argc)--;

    /* get spawnfn */
    spawnfn = *gasneti_getenv_withdefault("GASNET_SPAWNFN", _STRINGIFY(GASNETC_DEFAULT_SPAWNFN));

    { /* ensure we pass the effective spawnfn to worker env */
      char spawnstr[2];
      spawnstr[0] = toupper(spawnfn);
      spawnstr[1] = '\0';
      gasneti_setenv("GASNET_SPAWNFN",spawnstr);
    }

    /* ensure reliable localhost operation by forcing use of 127.0.0.1
     * setting GASNET_MASTERIP to the empty string will prevent this */
    if (('L' == toupper(spawnfn)) && !gasneti_getenv("GASNET_MASTERIP")) {
      gasneti_setenv("GASNET_MASTERIP","127.0.0.1");
    }

    for (i=0; AMUDP_Spawnfn_Desc[i].abbrev; i++) {
      if (toupper(spawnfn) == toupper(AMUDP_Spawnfn_Desc[i].abbrev)) {
        fp = AMUDP_Spawnfn_Desc[i].fnptr;
        break;
      }
    }

    if (!fp) {
      fprintf (stderr, "GASNet: Invalid spawn function specified in GASNET_SPAWNFN\n");
      fprintf (stderr, "GASNet: The following mechanisms are available:\n");
      for (i=0; AMUDP_Spawnfn_Desc[i].abbrev; i++) {
        fprintf(stderr, "    '%c'  %s\n",  
              toupper(AMUDP_Spawnfn_Desc[i].abbrev), AMUDP_Spawnfn_Desc[i].desc);
      }
      exit(1);
    }

    #if GASNET_DEBUG_VERBOSE
      /* note - can't call trace macros during gasnet_init because trace system not yet initialized */
      fprintf(stderr,"gasnetc_init(): about to spawn...\n"); fflush(stderr);
    #endif

    retval = AMUDP_SPMDStartup(argc, argv, 
      num_nodes, 0, fp,
      NULL, &gasnetc_bundle, &gasnetc_endpoint);
    /* master startup should never return */
    gasneti_fatalerror("master AMUDP_SPMDStartup() failed");
  }

  /* --------- begin Worker code ------------ */
  AMLOCK();
    if (gasneti_init_done) 
      INITERR(NOT_INIT, "GASNet already initialized");

    gasneti_freezeForDebugger();

    AMX_VerboseErrors = gasneti_VerboseErrors;
    AMUDP_SPMDkillmyprocess = gasneti_killmyprocess;

#if GASNETI_CALIBRATE_TSC
    // Early x86*/Linux timer initialization before AMUDP_SPMDStartup()
    //
    // udp-conduit does not support user-provided values for GASNET_TSC_RATE*
    // (which fine-tune timer calibration on x86/Linux).  This is partially due
    // to a dependency cycle at startup with envvar propagation, but more
    // importantly because the retransmission algorithm (and hence all conduit
    // comms) rely on gasnet timers to be accurate (at least approximately), so
    // we don't allow the user to weaken or disable their calibration.
    gasneti_unsetenv("GASNET_TSC_RATE");
    gasneti_unsetenv("GASNET_TSC_RATE_TOLERANCE");
    gasneti_unsetenv("GASNET_TSC_RATE_HARD_TOLERANCE");
    GASNETI_TICKS_INIT();
#endif

    /*  perform job spawn */
    retval = AMUDP_SPMDStartup(argc, argv, 
      0, 0, NULL, /* dummies */
      &gasnetc_networkpid, &gasnetc_bundle, &gasnetc_endpoint);
    if (retval != AM_OK) INITERR(RESOURCE, "slave AMUDP_SPMDStartup() failed");
    gasneti_init_done = 1; /* enable early to allow tracing */

    gasneti_getenv_hook = (/* cast drops const */ gasneti_getenv_fn_t*)&AMUDP_SPMDgetenvMaster;
    gasneti_mynode = AMUDP_SPMDMyProc();
    gasneti_nodes = AMUDP_SPMDNumProcs();

#if !GASNETI_CALIBRATE_TSC
    /* Must init timers after global env, and preferably before tracing */
    GASNETI_TICKS_INIT();
#endif

    /* enable tracing */
    gasneti_trace_init(argc, argv);
    GASNETI_AM_SAFE(AMUDP_SPMDSetExitCallback(gasnetc_traceoutput));

    /* for local spawn, assume we want to wait-block */
    if (gasneti_getenv("GASNET_SPAWNFN") && *gasneti_getenv("GASNET_SPAWNFN") == 'L') { 
      GASNETI_TRACE_PRINTF(C,("setting gasnet_set_waitmode(GASNET_WAIT_BLOCK) for localhost spawn"));
      gasnet_set_waitmode(GASNET_WAIT_BLOCK);
    }

    #if GASNET_DEBUG_VERBOSE
      fprintf(stderr,"gasnetc_init(): spawn successful - node %i/%i starting...\n", 
        gasneti_mynode, gasneti_nodes); fflush(stderr);
    #endif

    gasneti_nodemapInit(&gasnetc_bootstrapExchange, NULL, 0, 0);

    #if GASNET_PSHM
      gasneti_pshm_init(&gasnetc_bootstrapSNodeBroadcast, 0);
    #endif

    uintptr_t mmap_limit;
    #if HAVE_MMAP
      mmap_limit = gasneti_mmapLimit((uintptr_t)-1, (uint64_t)-1,
                                  &gasnetc_bootstrapExchange,
                                  &gasnetc_bootstrapBarrier);
    #else
      // TODO-EX: we can at least look at rlimits but such logic belongs in conduit-indep code
      mmap_limit = (intptr_t)-1;
    #endif

    /* allocate and attach an aux segment */

    gasneti_auxsegAttach(mmap_limit, &gasnetc_bootstrapExchange);

    /* determine Max{Local,GLobal}SegmentSize */
    gasneti_segmentInit(mmap_limit, &gasnetc_bootstrapExchange, flags);

    #if GASNET_BLCR
      gasneti_checkpoint_guid = gasnetc_networkpid;
      gasneti_checkpoint_init(NULL);
    #endif

  AMUNLOCK();

  gasneti_assert(retval == GASNET_OK);
  return retval;

done: /*  error return while locked */
  AMUNLOCK();
  GASNETI_RETURN(retval);
}