ref: c1d40df49550393f3afe53fb6e6d500dfa8eb7a8
dir: /sys/src/libdtracy/chan.c/
#include <u.h> #include <libc.h> #include <dtracy.h> int dtnmach; void dtinit(int nmach) { DTProvider **p; dtnmach = nmach; /* sanity */ for(p = dtproviders; *p != nil; p++){ assert((*p)->name != nil); assert((*p)->provide != nil); assert((*p)->enable != nil); assert((*p)->disable != nil); } } void dtsync(void) { int i; for(i = 0; i < dtnmach; i++){ dtmachlock(i); dtmachunlock(i); } } DTChan * dtcnew(void) { DTChan *c; int i; c = dtmalloc(sizeof(DTChan)); c->rdbufs = dtmalloc(sizeof(DTBuf *) * dtnmach); c->wrbufs = dtmalloc(sizeof(DTBuf *) * dtnmach); for(i = 0; i < dtnmach; i++){ c->rdbufs[i] = dtmalloc(sizeof(DTBuf)); c->wrbufs[i] = dtmalloc(sizeof(DTBuf)); } c->aggrdbufs = dtmalloc(sizeof(DTBuf *) * dtnmach); c->aggwrbufs = dtmalloc(sizeof(DTBuf *) * dtnmach); for(i = 0; i < dtnmach; i++){ c->aggrdbufs[i] = dtmalloc(sizeof(DTBuf)); c->aggwrbufs[i] = dtmalloc(sizeof(DTBuf)); memset(c->aggrdbufs[i]->data, -1, DTBUFSZ); memset(c->aggwrbufs[i]->data, -1, DTBUFSZ); } return c; } void dtcfree(DTChan *ch) { int i; if(ch == nil) return; dtcrun(ch, DTCSTOP); dtcreset(ch); dtsync(); for(i = 0; i < dtnmach; i++){ free(ch->rdbufs[i]); free(ch->wrbufs[i]); } free(ch->rdbufs); free(ch->wrbufs); for(i = 0; i < dtnmach; i++){ free(ch->aggrdbufs[i]); free(ch->aggwrbufs[i]); } free(ch->aggrdbufs); free(ch->aggwrbufs); free(ch); } int dtcaddgr(DTChan *c, char *name, DTActGr *gr) { DTProbe **l, *p; DTEnab *ep; int i, nl, n; if(dtgverify(c, gr) < 0) return -1; gr->chan = c; nl = dtpmatch(name, &l); if(nl == 0){ dtfree(l); werrstr("no match for %s", name); return -1; } n = 0; for(i = 0; i < nl; i++){ p = l[i]; if(p->nenable == 0) if(p->prov->enable(p) < 0) continue; ep = dtmalloc(sizeof(DTEnab)); ep->epid = c->epidalloc++; ep->gr = gr; ep->prob = p; ep->probnext = &p->enablist; ep->probprev = p->enablist.probprev; ep->probnext->probprev = ep; ep->channext = c->enab; c->enab = ep; gr->ref++; n++; p->nenable++; /* careful, has to be atomic for dtptrigger */ dtcoherence(); ep->probprev->probnext = ep; } dtfree(l); return n; } int dtcaddcl(DTChan *c, DTClause *cl) { int i, rc; rc = 0; for(i = 0; i < cl->nprob; i++) rc += dtcaddgr(c, cl->probs[i], cl->gr); return rc; } static void dtcbufswap(DTChan *c, int n) { DTBuf *z; dtmachlock(n); z = c->rdbufs[n]; c->rdbufs[n] = c->wrbufs[n]; c->wrbufs[n] = z; dtmachunlock(n); } int dtcread(DTChan *c, void *buf, int n) { int i, swapped; if(c->state == DTCFAULT){ werrstr("%s", c->errstr); return -1; } for(i = 0; i < dtnmach; i++){ if(swapped = c->rdbufs[i]->wr == 0) dtcbufswap(c, i); if(c->rdbufs[i]->wr != 0){ if(c->rdbufs[i]->wr > n){ werrstr("short read"); return -1; } n = c->rdbufs[i]->wr; memmove(buf, c->rdbufs[i]->data, n); c->rdbufs[i]->wr = 0; if(!swapped) dtcbufswap(c, i); return n; } } return 0; } static void dtcaggbufswap(DTChan *c, int n) { DTBuf *z; dtmachlock(n); z = c->aggrdbufs[n]; c->aggrdbufs[n] = c->aggwrbufs[n]; c->aggwrbufs[n] = z; dtmachunlock(n); } int dtcaggread(DTChan *c, void *buf, int n) { int i, swapped; if(c->state == DTCFAULT){ werrstr("%s", c->errstr); return -1; } for(i = 0; i < dtnmach; i++){ if(swapped = c->aggrdbufs[i]->wr == 0) dtcaggbufswap(c, i); if(c->aggrdbufs[i]->wr != 0){ if(c->aggrdbufs[i]->wr > n){ werrstr("short read"); return -1; } n = c->aggrdbufs[i]->wr; memmove(buf, c->aggrdbufs[i]->data, n); c->aggrdbufs[i]->wr = 0; memset(c->aggrdbufs[i]->data + DTABUCKETS, -1, 4 * DTANUMBUCKETS); if(!swapped) dtcaggbufswap(c, i); return n; } } return 0; } void dtcreset(DTChan *c) { DTEnab *ep, *eq; for(ep = c->enab; ep != nil; ep = ep->channext){ /* careful! has to look atomic for dtptrigger */ ep->probprev->probnext = ep->probnext; ep->probnext->probprev = ep->probprev; } dtsync(); for(ep = c->enab; ep != nil; eq = ep->channext, free(ep), ep = eq){ if(--ep->gr->ref == 0) dtgfree(ep->gr); if(--ep->prob->nenable == 0) ep->prob->prov->disable(ep->prob); } c->enab = nil; } void dtcrun(DTChan *c, int newstate) { assert(newstate == DTCSTOP || newstate == DTCGO); c->state = newstate; }