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static struct pe_watcher_vtbl pe_var_vtbl;
static pe_watcher *pe_var_allocate(HV *stash, SV *temple) {
pe_var *ev;
EvNew(10, ev, 1, pe_var);
ev->base.vtbl = &pe_var_vtbl;
pe_watcher_init(&ev->base, stash, temple);
ev->variable = &PL_sv_undef;
ev->events = PE_W;
WaREPEAT_on(ev);
WaINVOKE1_off(ev);
return (pe_watcher*) ev;
}
static void pe_var_dtor(pe_watcher *ev) {
pe_var *wv = (pe_var *)ev;
SvREFCNT_dec(wv->variable);
pe_watcher_dtor(ev);
EvFree(10, ev);
}
static void pe_tracevar(pe_watcher *wa, SV *sv, int got) {
/* Adapted from tkGlue.c
We are a "magic" set processor.
So we are (I think) supposed to look at "private" flags
and set the public ones if appropriate.
e.g. "chop" sets SvPOKp as a hint but not SvPOK
presumably other operators set other private bits.
Question are successive "magics" called in correct order?
i.e. if we are tracing a tied variable should we call
some magic list or be careful how we insert ourselves in the list?
*/
pe_ioevent *ev;
if (SvPOKp(sv)) SvPOK_on(sv);
if (SvNOKp(sv)) SvNOK_on(sv);
if (SvIOKp(sv)) SvIOK_on(sv);
ev = (pe_ioevent*) (*wa->vtbl->new_event)(wa);
++ev->base.hits;
ev->got |= got;
queueEvent((pe_event*) ev);
}
static I32 tracevar_r(pTHX_ IV ix, SV *sv)
{ pe_tracevar(INT2PTR(pe_watcher *, ix), sv, PE_R); return 0; /*ignored*/ }
static I32 tracevar_w(pTHX_ IV ix, SV *sv)
{ pe_tracevar(INT2PTR(pe_watcher *, ix), sv, PE_W); return 0; /*ignored*/ }
static char *pe_var_start(pe_watcher *_ev, int repeat) {
STRLEN n_a;
struct ufuncs *ufp;
MAGIC **mgp;
MAGIC *mg;
pe_var *ev = (pe_var*) _ev;
SV *sv = ev->variable;
if (!_ev->callback)
return "without callback";
if (!sv || !SvOK(sv))
return "watching what?";
if (!ev->events)
return "without poll events specified";
sv = SvRV(sv);
if (SvREADONLY(sv))
return "cannot trace read-only variable";
if (!SvUPGRADE(sv, SVt_PVMG))
return "SvUPGRADE failed";
mgp = &SvMAGIC(sv);
while ((mg = *mgp)) {
mgp = &mg->mg_moremagic;
}
EvNew(11, mg, 1, MAGIC);
Zero(mg, 1, MAGIC);
mg->mg_type = 'U';
mg->mg_virtual = &PL_vtbl_uvar;
*mgp = mg;
EvNew(8, ufp, 1, struct ufuncs);
ufp->uf_val = ev->events & PE_R? tracevar_r : 0;
ufp->uf_set = ev->events & PE_W? tracevar_w : 0;
ufp->uf_index = PTR2IV(ev);
mg->mg_ptr = (char *) ufp;
mg->mg_obj = (SV*) ev;
mg_magical(sv);
if (!SvMAGICAL(sv))
return "mg_magical didn't";
return 0;
}
static void pe_var_stop(pe_watcher *_ev) {
MAGIC **mgp;
MAGIC *mg;
pe_var *ev = (pe_var*) _ev;
SV *sv = SvRV(ev->variable);
if (SvTYPE(sv) < SVt_PVMG || !SvMAGIC(sv)) {
warn("Var unmagic'd already?");
return;
}
mgp = &SvMAGIC(sv);
while ((mg = *mgp)) {
if (mg->mg_type == 'U' && mg->mg_obj == (SV*)ev)
break;
mgp = &mg->mg_moremagic;
}
if(!mg) {
warn("Couldn't find var magic");
return;
}
*mgp = mg->mg_moremagic;
EvFree(8, mg->mg_ptr);
EvFree(11, mg);
}
static void _var_restart(pe_watcher *ev) {
if (!WaPOLLING(ev)) return;
pe_watcher_off(ev);
pe_watcher_on(ev, 0);
}
WKEYMETH(_var_events) {
pe_var *vp = (pe_var*)ev;
if (nval) {
vp->events = sv_2events_mask(nval, PE_R|PE_W);
_var_restart(ev);
}
{
dSP;
XPUSHs(sv_2mortal(events_mask_2sv(vp->events)));
PUTBACK;
}
}
WKEYMETH(_var_variable) {
pe_var *vp = (pe_var*)ev;
if (nval) {
SV *old = vp->variable;
int active = WaPOLLING(ev);
if (SvOK(nval)) {
if (!SvROK(nval))
croak("Expecting a reference");
if (SvTYPE(SvRV(nval)) > SVt_PVMG)
croak("Var watchers can only watch plain vanilla scalars");
}
if (active) pe_watcher_off(ev);
vp->variable = SvREFCNT_inc(nval);
if (active) pe_watcher_on(ev, 0);
SvREFCNT_dec(old);
}
{
dSP;
XPUSHs(vp->variable);
PUTBACK;
}
}
static void boot_var() {
pe_watcher_vtbl *vt = &pe_var_vtbl;
memcpy(vt, &pe_watcher_base_vtbl, sizeof(pe_watcher_base_vtbl));
vt->dtor = pe_var_dtor;
vt->start = pe_var_start;
vt->stop = pe_var_stop;
pe_register_vtbl(vt, gv_stashpv("Event::var",1), &ioevent_vtbl);
}
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