* This file is part of the public release of Spin. It is subject to the

/***** spin: sched.c *****/

/*
* This file is part of the public release of Spin. It is subject to the
* terms in the LICENSE file that is included in this source directory.
* Tool documentation is available at http://spinroot.com
*/

#include <stdlib.h>
#include "spin.h"
#include "y.tab.h"

extern int verbose, s_trail, analyze, no_wrapup;
extern char *claimproc, *eventmap, Buf[];
extern Ordered *all_names;
extern Symbol *Fname, *context;
extern int lineno, nr_errs, dumptab, xspin, jumpsteps, columns;
extern int u_sync, Elcnt, interactive, TstOnly, cutoff;
extern short has_enabled, has_priority, has_code, replay;
extern int limited_vis, product, nclaims, old_priority_rules;
extern int old_scope_rules, scope_seq[128], scope_level, has_stdin;

extern int pc_highest(Lextok *n);

RunList *X = (RunList *) 0;
RunList *run = (RunList *) 0;
RunList *LastX = (RunList *) 0; /* previous executing proc */
ProcList *rdy = (ProcList *) 0;
Element *LastStep = ZE;
int nproc=0, nstop=0, Tval=0, Priority_Sum = 0;
int Rvous=0, depth=0, nrRdy=0, MadeChoice;
short Have_claim=0, Skip_claim=0;

static void setlocals(RunList *);
static void setparams(RunList *, ProcList *, Lextok *);
static void talk(RunList *);

void
runnable(ProcList *p, int weight, int noparams)
{ RunList *r = (RunList *) emalloc(sizeof(RunList));

r->n = p->n;
r->tn = p->tn;
r->b = p->b;
r->pid = nproc++ - nstop + Skip_claim;
r->priority = weight;
p->priority = (unsigned char) weight; /* not quite the best place of course */

if (!noparams && ((verbose&4) || (verbose&32)))
{ printf("Starting %s with pid %d",
p->n?p->n->name:"--", r->pid);
if (has_priority) printf(" priority %d", r->priority);
printf("\n");
}
if (!p->s)
fatal("parsing error, no sequence %s",
p->n?p->n->name:"--");

r->pc = huntele(p->s->frst, p->s->frst->status, -1);
r->ps = p->s;

if (p->s->last)
p->s->last->status |= ENDSTATE; /* normal end state */

r->nxt = run;
r->prov = p->prov;
if (weight < 1 || weight > 255)
{ fatal("bad process priority, valid range: 1..255", (char *) 0);
}

if (noparams) setlocals(r);
Priority_Sum += weight;

run = r;
}

ProcList *
ready(Symbol *n, Lextok *p, Sequence *s, int det, Lextok *prov, enum btypes b)
/* n=name, p=formals, s=body det=deterministic prov=provided */
{ ProcList *r = (ProcList *) emalloc(sizeof(ProcList));
Lextok *fp, *fpt; int j; extern int Npars;

r->n = n;
r->p = p;
r->s = s;
r->b = b;
r->prov = prov;
r->tn = (short) nrRdy++;
n->sc = scope_seq[scope_level]; /* scope_level should be 0 */

if (det != 0 && det != 1)
{ fprintf(stderr, "spin: bad value for det (cannot happen)\n");
}
r->det = (unsigned char) det;
r->nxt = rdy;
rdy = r;

for (fp = p, j = 0; fp; fp = fp->rgt)
for (fpt = fp->lft; fpt; fpt = fpt->rgt)
j++; /* count # of parameters */
Npars = max(Npars, j);

return rdy;
}

int
find_maxel(Symbol *s)
{ ProcList *p;

for (p = rdy; p; p = p->nxt)
if (p->n == s)
return p->s->maxel++;
return Elcnt++;
}

static void
formdump(void)
{ ProcList *p;
Lextok *f, *t;
int cnt;

for (p = rdy; p; p = p->nxt)
{ if (!p->p) continue;
cnt = -1;
for (f = p->p; f; f = f->rgt) /* types */
for (t = f->lft; t; t = t->rgt) /* formals */
{ if (t->ntyp != ',')
t->sym->Nid = cnt--; /* overload Nid */
else
t->lft->sym->Nid = cnt--;
}
}
}

void
announce(char *w)
{
if (columns)
{ extern char Buf[];
extern int firstrow;
firstrow = 1;
if (columns == 2)
{ sprintf(Buf, "%d:%s",
run->pid - Have_claim, run->n->name);
pstext(run->pid - Have_claim, Buf);
} else
{ printf("proc %d = %s\n",
run->pid - Have_claim, run->n->name);
}
return;
}

if (dumptab
|| analyze
|| product
|| s_trail
|| !(verbose&4))
return;

if (w)
printf(" 0: proc - (%s) ", w);
else
whoruns(1);
printf("creates proc %2d (%s)",
run->pid - Have_claim,
run->n->name);
if (run->priority > 1)
printf(" priority %d", run->priority);
printf("\n");
}

#ifndef MAXP
#define MAXP 255 /* matches max nr of processes in verifier */
#endif

int
enable(Lextok *m)
{ ProcList *p;
Symbol *s = m->sym; /* proctype name */
Lextok *n = m->lft; /* actual parameters */

if (m->val < 1)
{ m->val = 1; /* minimum priority */
}
for (p = rdy; p; p = p->nxt)
{ if (strcmp(s->name, p->n->name) == 0)
{ if (nproc-nstop >= MAXP)
{ printf("spin: too many processes (%d max)\n", MAXP);
break;
}
runnable(p, m->val, 0);
announce((char *) 0);
setparams(run, p, n);
setlocals(run); /* after setparams */
return run->pid - Have_claim + Skip_claim; /* effective simu pid */
} }
return 0; /* process not found */
}

void
check_param_count(int i, Lextok *m)
{ ProcList *p;
Symbol *s = m->sym; /* proctype name */
Lextok *f, *t; /* formal pars */
int cnt = 0;

for (p = rdy; p; p = p->nxt)
{ if (strcmp(s->name, p->n->name) == 0)
{ if (m->lft) /* actual param list */
{ lineno = m->lft->ln;
Fname = m->lft->fn;
}
for (f = p->p; f; f = f->rgt) /* one type at a time */
for (t = f->lft; t; t = t->rgt) /* count formal params */
{ cnt++;
}
if (i != cnt)
{ printf("spin: saw %d parameters, expected %d\n", i, cnt);
non_fatal("wrong number of parameters", "");
}
break;
} }
}

void
start_claim(int n)
{ ProcList *p;
RunList *r, *q = (RunList *) 0;

for (p = rdy; p; p = p->nxt)
if (p->tn == n && p->b == N_CLAIM)
{ runnable(p, 1, 1);
goto found;
}
printf("spin: couldn't find claim %d (ignored)\n", n);
if (verbose&32)
for (p = rdy; p; p = p->nxt)
printf("\t%d = %s\n", p->tn, p->n->name);

Skip_claim = 1;
goto done;
found:
/* move claim to far end of runlist, and reassign it pid 0 */
if (columns == 2)
{ extern char Buf[];
depth = 0;
sprintf(Buf, "%d:%s", 0, p->n->name);
pstext(0, Buf);
for (r = run; r; r = r->nxt)
{ if (r->b != N_CLAIM)
{ sprintf(Buf, "%d:%s", r->pid+1, r->n->name);
pstext(r->pid+1, Buf);
} } }

if (run->pid == 0) return; /* it is the first process started */

q = run; run = run->nxt;
q->pid = 0; q->nxt = (RunList *) 0; /* remove */
done:
Have_claim = 1;
for (r = run; r; r = r->nxt)
{ r->pid = r->pid+Have_claim; /* adjust */
if (!r->nxt)
{ r->nxt = q;
break;
} }
}

int
f_pid(char *n)
{ RunList *r;
int rval = -1;

for (r = run; r; r = r->nxt)
if (strcmp(n, r->n->name) == 0)
{ if (rval >= 0)
{ printf("spin: remote ref to proctype %s, ", n);
printf("has more than one match: %d and %d\n",
rval, r->pid);
} else
rval = r->pid;
}
return rval;
}

void
wrapup(int fini)
{
limited_vis = 0;
if (columns)
{ extern void putpostlude(void);
if (columns == 2) putpostlude();
if (!no_wrapup)
printf("-------------\nfinal state:\n-------------\n");
}
if (no_wrapup)
goto short_cut;
if (nproc != nstop)
{ int ov = verbose;
printf("#processes: %d\n", nproc-nstop - Have_claim + Skip_claim);
verbose &= ~4;
dumpglobals();
verbose = ov;
verbose &= ~1; /* no more globals */
verbose |= 32; /* add process states */
for (X = run; X; X = X->nxt)
talk(X);
verbose = ov; /* restore */
}
printf("%d process%s created\n",
nproc - Have_claim + Skip_claim,
(xspin || nproc!=1)?"es":"");
short_cut:
if (s_trail || xspin) alldone(0); /* avoid an abort from xspin */
if (fini) alldone(1);
}

static char is_blocked[256];

static int
p_blocked(int p)
{ int i, j;

is_blocked[p%256] = 1;
for (i = j = 0; i < nproc - nstop; i++)
j += is_blocked[i];
if (j >= nproc - nstop)
{ memset(is_blocked, 0, 256);
return 1;
}
return 0;
}

static Element *
silent_moves(Element *e)
{ Element *f;

if (e->n)
switch (e->n->ntyp) {
case GOTO:
if (Rvous) break;
f = get_lab(e->n, 1);
cross_dsteps(e->n, f->n);
return f; /* guard against goto cycles */
case UNLESS:
return silent_moves(e->sub->this->frst);
case NON_ATOMIC:
case ATOMIC:
case D_STEP:
e->n->sl->this->last->nxt = e->nxt;
return silent_moves(e->n->sl->this->frst);
case '.':
return silent_moves(e->nxt);
}
return e;
}

static int
x_can_run(void) /* the currently selected process in X can run */
{
if (X->prov && !eval(X->prov))
{
if (0) printf("pid %d cannot run: not provided\n", X->pid);
return 0;
}
if (has_priority && !old_priority_rules)
{ Lextok *n = nn(ZN, CONST, ZN, ZN);
n->val = X->pid;
if (0) printf("pid %d %s run (priority)\n", X->pid, pc_highest(n)?"can":"cannot");
return pc_highest(n);
}
if (0) printf("pid %d can run\n", X->pid);
return 1;
}

static RunList *
pickproc(RunList *Y)
{ SeqList *z; Element *has_else;
short Choices[256];
int j, k, nr_else = 0;

if (nproc <= nstop+1)
{ X = run;
return NULL;
}
if (!interactive || depth < jumpsteps)
{ if (has_priority && !old_priority_rules) /* new 6.3.2 */
{ j = Rand()%(nproc-nstop);
for (X = run; X; X = X->nxt)
{ if (j-- <= 0)
break;
}
if (X == NULL)
{ fatal("unexpected, pickproc", (char *)0);
}
j = nproc - nstop;
while (j-- > 0)
{ if (x_can_run())
{ Y = X;
break;
}
X = (X->nxt)?X->nxt:run;
}
return Y;
}
if (Priority_Sum < nproc-nstop)
fatal("cannot happen - weights", (char *)0);
j = (int) Rand()%Priority_Sum;

while (j - X->priority >= 0)
{ j -= X->priority;
Y = X;
X = X->nxt;
if (!X) { Y = NULL; X = run; }
}

} else
{ int only_choice = -1;
int no_choice = 0, proc_no_ch, proc_k;

Tval = 0; /* new 4.2.6 */
try_again: printf("Select a statement\n");
try_more: for (X = run, k = 1; X; X = X->nxt)
{ if (X->pid > 255) break;

Choices[X->pid] = (short) k;

if (!X->pc || !x_can_run())
{ if (X == run)
Choices[X->pid] = 0;
continue;
}
X->pc = silent_moves(X->pc);
if (!X->pc->sub && X->pc->n)
{ int unex;
unex = !Enabled0(X->pc);
if (unex)
no_choice++;
else
only_choice = k;
if (!xspin && unex && !(verbose&32))
{ k++;
continue;
}
printf("\tchoice %d: ", k++);
p_talk(X->pc, 0);
if (unex)
printf(" unexecutable,");
printf(" [");
comment(stdout, X->pc->n, 0);
if (X->pc->esc) printf(" + Escape");
printf("]\n");
} else {
has_else = ZE;
proc_no_ch = no_choice;
proc_k = k;
for (z = X->pc->sub, j=0; z; z = z->nxt)
{ Element *y = silent_moves(z->this->frst);
int unex;
if (!y) continue;

if (y->n->ntyp == ELSE)
{ has_else = (Rvous)?ZE:y;
nr_else = k++;
continue;
}

unex = !Enabled0(y);
if (unex)
no_choice++;
else
only_choice = k;
if (!xspin && unex && !(verbose&32))
{ k++;
continue;
}
printf("\tchoice %d: ", k++);
p_talk(X->pc, 0);
if (unex)
printf(" unexecutable,");
printf(" [");
comment(stdout, y->n, 0);
printf("]\n");
}
if (has_else)
{ if (no_choice-proc_no_ch >= (k-proc_k)-1)
{ only_choice = nr_else;
printf("\tchoice %d: ", nr_else);
p_talk(X->pc, 0);
printf(" [else]\n");
} else
{ no_choice++;
printf("\tchoice %d: ", nr_else);
p_talk(X->pc, 0);
printf(" unexecutable, [else]\n");
} }
} }
X = run;
if (k - no_choice < 2 && Tval == 0)
{ Tval = 1;
no_choice = 0; only_choice = -1;
goto try_more;
}
if (xspin)
printf("Make Selection %d\n\n", k-1);
else
{ if (k - no_choice < 2)
{ printf("no executable choices\n");
alldone(0);
}
printf("Select [1-%d]: ", k-1);
}
if (!xspin && k - no_choice == 2)
{ printf("%d\n", only_choice);
j = only_choice;
} else
{ char buf[256];
fflush(stdout);
if (scanf("%64s", buf) == 0)
{ printf("\tno input\n");
goto try_again;
}
j = -1;
if (isdigit((int) buf[0]))
j = atoi(buf);
else
{ if (buf[0] == 'q')
alldone(0);
}
if (j < 1 || j >= k)
{ printf("\tchoice is outside range\n");
goto try_again;
} }
MadeChoice = 0;
Y = NULL;
for (X = run; X; Y = X, X = X->nxt)
{ if (!X->nxt
|| X->nxt->pid > 255
|| j < Choices[X->nxt->pid])
{
MadeChoice = 1+j-Choices[X->pid];
break;
} }
}
return Y;
}

void
multi_claims(void)
{ ProcList *p, *q = NULL;

if (nclaims > 1)
{ printf(" the model contains %d never claims:", nclaims);
for (p = rdy; p; p = p->nxt)
{ if (p->b == N_CLAIM)
{ printf("%s%s", q?", ":" ", p->n->name);
q = p;
} }
printf("\n");
printf(" only one claim is used in a verification run\n");
printf(" choose which one with ./pan -a -N name (defaults to -N %s)\n",
q?q->n->name:"--");
printf(" or use e.g.: spin -search -ltl %s %s\n",
q?q->n->name:"--", Fname?Fname->name:"filename");
}
}

void
sched(void)
{ Element *e;
RunList *Y = NULL; /* previous process in run queue */
RunList *oX;
int go, notbeyond = 0;
#ifdef PC
int bufmax = 100;
#endif
if (dumptab)
{ formdump();
symdump();
dumplabels();
return;
}
if (has_code && !analyze)
{ printf("spin: warning: c_code fragments remain uninterpreted\n");
printf(" in random simulations with spin; use ./pan -r instead\n");
}

if (has_enabled && u_sync > 0)
{ printf("spin: error, cannot use 'enabled()' in ");
printf("models with synchronous channels.\n");
nr_errs++;
}
if (product)
{ sync_product();
alldone(0);
}
if (analyze && (!replay || has_code))
{ gensrc();
multi_claims();
return;
}
if (replay && !has_code)
{ return;
}
if (s_trail)
{ match_trail();
return;
}

if (claimproc)
printf("warning: never claim not used in random simulation\n");
if (eventmap)
printf("warning: trace assertion not used in random simulation\n");

X = run;
Y = pickproc(Y);

while (X)
{ context = X->n;
if (X->pc && X->pc->n)
{ lineno = X->pc->n->ln;
Fname = X->pc->n->fn;
}
if (cutoff > 0 && depth >= cutoff)
{ printf("-------------\n");
printf("depth-limit (-u%d steps) reached\n", cutoff);
break;
}
#ifdef PC
if (xspin && !interactive && --bufmax <= 0)
{ int c; /* avoid buffer overflow on pc's */
printf("spin: type return to proceed\n");
fflush(stdout);
c = getc(stdin);
if (c == 'q') wrapup(0);
bufmax = 100;
}
#endif
depth++; LastStep = ZE;
oX = X; /* a rendezvous could change it */
go = 1;
if (X->pc
&& !(X->pc->status & D_ATOM)
&& !x_can_run())
{ if (!xspin && ((verbose&32) || (verbose&4)))
{ p_talk(X->pc, 1);
printf("\t<<Not Enabled>>\n");
}
go = 0;
}
if (go && (e = eval_sub(X->pc)))
{ if (depth >= jumpsteps
&& ((verbose&32) || (verbose&4)))
{ if (X == oX)
if (!(e->status & D_ATOM) || (verbose&32)) /* no talking in d_steps */
{ if (!LastStep) LastStep = X->pc;
/* A. Tanaka, changed order */
p_talk(LastStep, 1);
printf(" [");
comment(stdout, LastStep->n, 0);
printf("]\n");
}
if (verbose&1) dumpglobals();
if (verbose&2) dumplocal(X);

if (!(e->status & D_ATOM))
if (xspin)
printf("\n");
}
if (oX != X
|| (X->pc->status & (ATOM|D_ATOM))) /* new 5.0 */
{ e = silent_moves(e);
notbeyond = 0;
}
oX->pc = e; LastX = X;

if (!interactive) Tval = 0;
memset(is_blocked, 0, 256);

if (X->pc && (X->pc->status & (ATOM|L_ATOM))
&& (notbeyond == 0 || oX != X))
{ if ((X->pc->status & L_ATOM))
notbeyond = 1;
continue; /* no process switch */
}
} else
{ depth--;
if (oX->pc && (oX->pc->status & D_ATOM))
{ non_fatal("stmnt in d_step blocks", (char *)0);
}
if (X->pc
&& X->pc->n
&& X->pc->n->ntyp == '@'
&& X->pid == (nproc-nstop-1))
{ if (X != run && Y != NULL)
Y->nxt = X->nxt;
else
run = X->nxt;
nstop++;
Priority_Sum -= X->priority;
if (verbose&4)
{ whoruns(1);
dotag(stdout, "terminates\n");
}
LastX = X;
if (!interactive) Tval = 0;
if (nproc == nstop) break;
memset(is_blocked, 0, 256);
/* proc X is no longer in runlist */
X = (X->nxt) ? X->nxt : run;
} else
{ if (p_blocked(X->pid))
{ if (Tval && !has_stdin)
{ break;
}
if (!Tval && depth >= jumpsteps)
{ oX = X;
X = (RunList *) 0; /* to suppress indent */
dotag(stdout, "timeout\n");
X = oX;
Tval = 1;
} } } }

if (!run || !X) break; /* new 5.0 */

Y = pickproc(X);
notbeyond = 0;
}
context = ZS;
wrapup(0);
}

int
complete_rendez(void)
{ RunList *orun = X, *tmp;
Element *s_was = LastStep;
Element *e;
int j, ointer = interactive;

if (s_trail)
return 1;
if (orun->pc->status & D_ATOM)
fatal("rv-attempt in d_step sequence", (char *)0);
Rvous = 1;
interactive = 0;

j = (int) Rand()%Priority_Sum; /* randomize start point */
X = run;
while (j - X->priority >= 0)
{ j -= X->priority;
X = X->nxt;
if (!X) X = run;
}
for (j = nproc - nstop; j > 0; j--)
{ if (X != orun
&& (!X->prov || eval(X->prov))
&& (e = eval_sub(X->pc)))
{ if (TstOnly)
{ X = orun;
Rvous = 0;
goto out;
}
if ((verbose&32) || (verbose&4))
{ tmp = orun; orun = X; X = tmp;
if (!s_was) s_was = X->pc;
p_talk(s_was, 1);
printf(" [");
comment(stdout, s_was->n, 0);
printf("]\n");
tmp = orun; /* orun = X; */ X = tmp;
if (!LastStep) LastStep = X->pc;
p_talk(LastStep, 1);
printf(" [");
comment(stdout, LastStep->n, 0);
printf("]\n");
}
Rvous = 0; /* before silent_moves */
X->pc = silent_moves(e);
out: interactive = ointer;
return 1;
}

X = X->nxt;
if (!X) X = run;
}
Rvous = 0;
X = orun;
interactive = ointer;
return 0;
}

/***** Runtime - Local Variables *****/

static void
addsymbol(RunList *r, Symbol *s)
{ Symbol *t;
int i;

for (t = r->symtab; t; t = t->next)
if (strcmp(t->name, s->name) == 0
&& (old_scope_rules
|| strcmp((const char *)t->bscp, (const char *)s->bscp) == 0))
return; /* it's already there */

t = (Symbol *) emalloc(sizeof(Symbol));
t->name = s->name;
t->type = s->type;
t->hidden = s->hidden;
t->isarray = s->isarray;
t->nbits = s->nbits;
t->nel = s->nel;
t->ini = s->ini;
t->setat = depth;
t->context = r->n;

t->bscp = (unsigned char *) emalloc(strlen((const char *)s->bscp)+1);
strcpy((char *)t->bscp, (const char *)s->bscp);

if (s->type != STRUCT)
{ if (s->val) /* if already initialized, copy info */
{ t->val = (int *) emalloc(s->nel*sizeof(int));
for (i = 0; i < s->nel; i++)
t->val[i] = s->val[i];
} else
{ (void) checkvar(t, 0); /* initialize it */
}
} else
{ if (s->Sval)
fatal("saw preinitialized struct %s", s->name);
t->Slst = s->Slst;
t->Snm = s->Snm;
t->owner = s->owner;
/* t->context = r->n; */
}
t->next = r->symtab; /* add it */
r->symtab = t;
}

static void
setlocals(RunList *r)
{ Ordered *walk;
Symbol *sp;
RunList *oX = X;

X = r;
for (walk = all_names; walk; walk = walk->next)
{ sp = walk->entry;
if (sp
&& sp->context
&& strcmp(sp->context->name, r->n->name) == 0
&& sp->Nid >= 0
&& (sp->type == UNSIGNED
|| sp->type == BIT
|| sp->type == MTYPE
|| sp->type == BYTE
|| sp->type == CHAN
|| sp->type == SHORT
|| sp->type == INT
|| sp->type == STRUCT))
{ if (!findloc(sp))
non_fatal("setlocals: cannot happen '%s'",
sp->name);
}
}
X = oX;
}

static void
oneparam(RunList *r, Lextok *t, Lextok *a, ProcList *p)
{ int k; int at, ft;
RunList *oX = X;

if (!a)
fatal("missing actual parameters: '%s'", p->n->name);
if (t->sym->nel > 1 || t->sym->isarray)
fatal("array in parameter list, %s", t->sym->name);
k = eval(a->lft);

at = Sym_typ(a->lft);
X = r; /* switch context */
ft = Sym_typ(t);

if (at != ft && (at == CHAN || ft == CHAN))
{ char buf[256], tag1[64], tag2[64];
(void) sputtype(tag1, ft);
(void) sputtype(tag2, at);
sprintf(buf, "type-clash in params of %s(..), (%s<-> %s)",
p->n->name, tag1, tag2);
non_fatal("%s", buf);
}
t->ntyp = NAME;
addsymbol(r, t->sym);
(void) setval(t, k);

X = oX;
}

static void
setparams(RunList *r, ProcList *p, Lextok *q)
{ Lextok *f, *a; /* formal and actual pars */
Lextok *t; /* list of pars of 1 type */

if (q)
{ lineno = q->ln;
Fname = q->fn;
}
for (f = p->p, a = q; f; f = f->rgt) /* one type at a time */
for (t = f->lft; t; t = t->rgt, a = (a)?a->rgt:a)
{ if (t->ntyp != ',')
oneparam(r, t, a, p); /* plain var */
else
oneparam(r, t->lft, a, p); /* expanded struct */
}
}

Symbol *
findloc(Symbol *s)
{ Symbol *r;

if (!X)
{ /* fatal("error, cannot eval '%s' (no proc)", s->name); */
return ZS;
}
for (r = X->symtab; r; r = r->next)
{ if (strcmp(r->name, s->name) == 0
&& (old_scope_rules
|| strcmp((const char *)r->bscp, (const char *)s->bscp) == 0))
{ break;
} }
if (!r)
{ addsymbol(X, s);
r = X->symtab;
}
return r;
}

int
in_bound(Symbol *r, int n)
{
if (!r) return 0;

if (n >= r->nel || n < 0)
{ printf("spin: indexing %s[%d] - size is %d\n",
r->name, n, r->nel);
non_fatal("indexing array \'%s\'", r->name);
return 0;
}
return 1;
}

int
getlocal(Lextok *sn)
{ Symbol *r, *s = sn->sym;
int n = eval(sn->lft);

r = findloc(s);
if (r && r->type == STRUCT)
return Rval_struct(sn, r, 1); /* 1 = check init */
if (in_bound(r, n))
return cast_val(r->type, r->val[n], r->nbits);
return 0;
}

int
setlocal(Lextok *p, int m)
{ Symbol *r = findloc(p->sym);
int n = eval(p->lft);

if (in_bound(r, n))
{ if (r->type == STRUCT)
(void) Lval_struct(p, r, 1, m); /* 1 = check init */
else
{
#if 0
if (r->nbits > 0)
m = (m & ((1<<r->nbits)-1));
r->val[n] = m;
#else
r->val[n] = cast_val(r->type, m, r->nbits);
#endif
r->setat = depth;
} }

return 1;
}

void
whoruns(int lnr)
{ if (!X) return;

if (lnr) printf("%3d: ", depth);
printf("proc ");
if (Have_claim && X->pid == 0)
printf(" -");
else
printf("%2d", X->pid - Have_claim);
if (old_priority_rules)
{ printf(" (%s) ", X->n->name);
} else
{ printf(" (%s:%d) ", X->n->name, X->priority);
}
}

static void
talk(RunList *r)
{
if ((verbose&32) || (verbose&4))
{ p_talk(r->pc, 1);
printf("\n");
if (verbose&1) dumpglobals();
if (verbose&2) dumplocal(r);
}
}

void
p_talk(Element *e, int lnr)
{ static int lastnever = -1;
static char nbuf[128];
int newnever = -1;

if (e && e->n)
newnever = e->n->ln;

if (Have_claim && X && X->pid == 0
&& lastnever != newnever && e)
{ if (xspin)
{ printf("MSC: ~G line %d\n", newnever);
#if 0
printf("%3d: proc - (NEVER) line %d \"never\" ",
depth, newnever);
printf("(state 0)\t[printf('MSC: never\\\\n')]\n");
} else
{ printf("%3d: proc - (NEVER) line %d \"never\"\n",
depth, newnever);
#endif
}
lastnever = newnever;
}

whoruns(lnr);
if (e)
{ if (e->n)
{ char *ptr = e->n->fn->name;
char *qtr = nbuf;
while (*ptr != '\0')
{ if (*ptr != '"')
{ *qtr++ = *ptr;
}
ptr++;
}
*qtr = '\0';
} else
{ strcpy(nbuf, "-");
}
printf("%s:%d (state %d)",
nbuf,
e->n?e->n->ln:-1,
e->seqno);
if (!xspin
&& ((e->status&ENDSTATE) || has_lab(e, 2))) /* 2=end */
{ printf(" <valid end state>");
}
}
}

int
remotelab(Lextok *n)
{ int i;

lineno = n->ln;
Fname = n->fn;
if (n->sym->type != 0 && n->sym->type != LABEL)
{ printf("spin: error, type: %d\n", n->sym->type);
fatal("not a labelname: '%s'", n->sym->name);
}
if (n->indstep >= 0)
{ fatal("remote ref to label '%s' inside d_step",
n->sym->name);
}
if ((i = find_lab(n->sym, n->lft->sym, 1)) == 0) /* remotelab */
{ fatal("unknown labelname: %s", n->sym->name);
}
return i;
}

int
remotevar(Lextok *n)
{ int prno, i, added=0;
RunList *Y, *oX;
Lextok *onl;
Symbol *os;

lineno = n->ln;
Fname = n->fn;

if (!n->lft->lft)
prno = f_pid(n->lft->sym->name);
else
{ prno = eval(n->lft->lft); /* pid - can cause recursive call */
#if 0
if (n->lft->lft->ntyp == CONST) /* user-guessed pid */
#endif
{ prno += Have_claim;
added = Have_claim;
} }

if (prno < 0)
{ return 0; /* non-existing process */
}
#if 0
i = nproc - nstop;
for (Y = run; Y; Y = Y->nxt)
{ --i;
printf(" %s: i=%d, prno=%d, ->pid=%d\n", Y->n->name, i, prno, Y->pid);
}
#endif
i = nproc - nstop + Skip_claim; /* 6.0: added Skip_claim */
for (Y = run; Y; Y = Y->nxt)
if (--i == prno)
{ if (strcmp(Y->n->name, n->lft->sym->name) != 0)
{ printf("spin: remote reference error on '%s[%d]'\n",
n->lft->sym->name, prno-added);
non_fatal("refers to wrong proctype '%s'", Y->n->name);
}
if (strcmp(n->sym->name, "_p") == 0)
{ if (Y->pc)
{ return Y->pc->seqno;
}
/* harmless, can only happen with -t */
return 0;
}

/* check remote variables */
oX = X;
X = Y;

onl = n->lft;
n->lft = n->rgt;

os = n->sym;
if (!n->sym->context)
{ n->sym->context = Y->n;
}
{ int rs = old_scope_rules;
old_scope_rules = 1; /* 6.4.0 */
n->sym = findloc(n->sym);
old_scope_rules = rs;
}
i = getval(n);

n->sym = os;
n->lft = onl;
X = oX;
return i;
}
printf("remote ref: %s[%d] ", n->lft->sym->name, prno-added);
non_fatal("%s not found", n->sym->name);
printf("have only:\n");
i = nproc - nstop - 1;
for (Y = run; Y; Y = Y->nxt, i--)
if (!strcmp(Y->n->name, n->lft->sym->name))
printf("\t%d\t%s\n", i, Y->n->name);

return 0;
}