diff options
Diffstat (limited to 'libinterp/alt.c')
| -rw-r--r-- | libinterp/alt.c | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/libinterp/alt.c b/libinterp/alt.c new file mode 100644 index 00000000..61bda2e3 --- /dev/null +++ b/libinterp/alt.c @@ -0,0 +1,297 @@ +#include "lib9.h" +#include "isa.h" +#include "interp.h" +#include "raise.h" + +#define OP(fn) void fn(void) +#define W(p) *((WORD*)(p)) + +#define CANGET(c) ((c)->size > 0) +#define CANPUT(c) ((c)->buf != H && (c)->size < (c)->buf->len) + +extern OP(isend); +extern OP(irecv); + +/* + * Count the number of ready channels in an array of channels + * Set each channel's alt pointer to the owning prog + */ +static int +altmark(Channel *c, Prog *p) +{ + int nrdy; + Array *a; + Channel **ca, **ec; + + nrdy = 0; + a = (Array*)c; + ca = (Channel**)a->data; + ec = ca + a->len; + while(ca < ec) { + c = *ca; + if(c != H) { + if(c->send->prog || CANGET(c)) + nrdy++; + cqadd(&c->recv, p); + } + ca++; + } + + return nrdy; +} + +/* + * Remove alt references to an array of channels + */ +static void +altunmark(Channel *c, WORD *ptr, Prog *p, int sr, Channel **sel, int dn) +{ + int n; + Array *a; + Channel **ca, **ec; + + n = 0; + a = (Array*)c; + ca = (Channel**)a->data; + ec = ca + a->len; + while(ca < ec) { + c = *ca; + if(c != H && c->recv->prog) + cqdelp(&c->recv, p); + if(sr == 1 && *sel == c) { + W(p->R.d) = dn; + p->ptr = ptr + 1; + ptr[0] = n; + *sel = nil; + } + ca++; + n++; + } +} + +/* + * ALT Pass 1 - Count the number of ready channels and mark + * each channel as ALT by this prog + */ +static int +altrdy(Alt *a, Prog *p) +{ + char *e; + Type *t; + int nrdy; + Channel *c; + Altc *ac, *eac; + + e = nil; + nrdy = 0; + + ac = a->ac + a->nsend; + eac = ac + a->nrecv; + while(ac < eac) { + c = ac->c; + ac++; + if(c == H) { + e = exNilref; + continue; + } + t = D2H(c)->t; + if(t == &Tarray) + nrdy += altmark(c, p); + else { + if(c->send->prog || CANGET(c)) + nrdy++; + cqadd(&c->recv, p); + } + } + + ac = a->ac; + eac = ac + a->nsend; + while(ac < eac) { + c = ac->c; + ac++; + if(c == H) { + e = exNilref; + continue; + } + if(c->recv->prog || CANPUT(c)) { + if(c->recv->prog == p) { + e = exAlt; + continue; + } + nrdy++; + } + cqadd(&c->send, p); + } + + if(e != nil) { + altdone(a, p, nil, -1); + error(e); + } + + return nrdy; +} + +/* + * ALT Pass 3 - Pull out of an ALT cancelling the channel pointers in each item + */ +void +altdone(Alt *a, Prog *p, Channel *sel, int sr) +{ + int n; + Type *t; + Channel *c; + Altc *ac, *eac; + + n = 0; + ac = a->ac; + eac = a->ac + a->nsend; + while(ac < eac) { + c = ac->c; + if(c != H) { + if(c->send->prog) + cqdelp(&c->send, p); + if(sr == 0 && c == sel) { + p->ptr = ac->ptr; + W(p->R.d) = n; + sel = nil; + } + } + ac++; + n++; + } + + eac = a->ac + a->nsend + a->nrecv; + while(ac < eac) { + c = ac->c; + if(c != H) { + t = D2H(c)->t; + if(t == &Tarray) + altunmark(c, ac->ptr, p, sr, &sel, n); + else { + if(c->recv->prog) + cqdelp(&c->recv, p); + if(sr == 1 && c == sel) { + p->ptr = ac->ptr; + W(p->R.d) = n; + sel = nil; + } + } + } + ac++; + n++; + } +} + +/* + * ALT Pass 2 - Perform the communication on the chosen channel + */ +static void +altcomm(Alt *a, int which) +{ + Type *t; + Array *r; + int n, an; + WORD *ptr; + Altc *ac, *eac; + Channel *c, **ca, **ec; + + n = 0; + ac = a->ac; + eac = ac + a->nsend; + while(ac < eac) { + c = ac->c; + if((c->recv->prog != nil || CANPUT(c)) && which-- == 0) { + W(R.d) = n; + R.s = ac->ptr; + R.d = &c; + isend(); + return; + } + ac++; + n++; + } + + eac = eac + a->nrecv; + while(ac < eac) { + c = ac->c; + t = D2H(c)->t; + if(t == &Tarray) { + an = 0; + r = (Array*)c; + ca = (Channel**)r->data; + ec = ca + r->len; + while(ca < ec) { + c = *ca; + if(c != H && (c->send->prog != nil || CANGET(c)) && which-- == 0) { + W(R.d) = n; + R.s = &c; + ptr = ac->ptr; + R.d = ptr + 1; + ptr[0] = an; + irecv(); + return; + } + ca++; + an++; + } + } + else + if((c->send->prog != nil || CANGET(c)) && which-- == 0) { + W(R.d) = n; + R.s = &c; + R.d = ac->ptr; + irecv(); + return; + } + ac++; + n++; + } + return; +} + +void +altgone(Prog *p) +{ + Alt *a; + + if (p->state == Palt) { + a = p->R.s; + altdone(a, p, nil, -1); + p->kill = "alt channel hungup"; + addrun(p); + } +} + +void +xecalt(int block) +{ + Alt *a; + Prog *p; + int nrdy; + static int xrand = -1; + + p = currun(); + + a = R.s; + nrdy = altrdy(a, p); + if(nrdy == 0) { + if(block) { + delrun(Palt); + p->R.s = R.s; + p->R.d = R.d; + R.IC = 1; + R.t = 1; + return; + } + W(R.d) = a->nsend + a->nrecv; + altdone(a, p, nil, -1); + return; + } + + xrand += xrand; + if(xrand < 0) + xrand ^= 0x88888EEF; + + altcomm(a, xrand%nrdy); + altdone(a, p, nil, -1); +} |