ref: df8c7d8fd8b3e2d81c887a5072d72f179fd0691e
dir: /kern/pgrp.c/
#include "u.h" #include "lib.h" #include "dat.h" #include "fns.h" #include "error.h" static Ref pgrpid; static Ref mountid; Pgrp* newpgrp(void) { Pgrp *p; p = smalloc(sizeof(Pgrp)); p->ref.ref = 1; p->pgrpid = incref(&pgrpid); return p; } Rgrp* newrgrp(void) { Rgrp *r; r = smalloc(sizeof(Rgrp)); r->ref.ref = 1; return r; } void closergrp(Rgrp *r) { if(decref(&r->ref) == 0) free(r); } void closepgrp(Pgrp *p) { Mhead **h, **e, *f; Mount *m; if(decref(&p->ref)) return; e = &p->mnthash[MNTHASH]; for(h = p->mnthash; h < e; h++) { while((f = *h) != nil){ *h = f->hash; wlock(&f->lock); m = f->mount; f->mount = nil; wunlock(&f->lock); mountfree(m); putmhead(f); } } free(p); } void pgrpinsert(Mount **order, Mount *m) { Mount *f; m->order = nil; if(*order == nil) { *order = m; return; } for(f = *order; f != nil; f = f->order) { if(m->mountid < f->mountid) { m->order = f; *order = m; return; } order = &f->order; } *order = m; } /* * pgrpcpy MUST preserve the mountid allocation order of the parent group */ void pgrpcpy(Pgrp *to, Pgrp *from) { Mount *n, *m, **link, *order; Mhead *f, **tom, **l, *mh; int i; wlock(&to->ns); rlock(&from->ns); order = nil; tom = to->mnthash; for(i = 0; i < MNTHASH; i++) { l = tom++; for(f = from->mnthash[i]; f != nil; f = f->hash) { rlock(&f->lock); mh = newmhead(f->from); *l = mh; l = &mh->hash; link = &mh->mount; for(m = f->mount; m != nil; m = m->next) { n = smalloc(sizeof(Mount)); n->mountid = m->mountid; n->mflag = m->mflag; n->to = m->to; incref(&n->to->ref); if(m->spec != nil) kstrdup(&n->spec, m->spec); pgrpinsert(&order, n); *link = n; link = &n->next; } runlock(&f->lock); } } /* * Allocate mount ids in the same sequence as the parent group */ for(m = order; m != nil; m = m->order) m->mountid = incref(&mountid); runlock(&from->ns); wunlock(&to->ns); } Fgrp* dupfgrp(Fgrp *f) { Fgrp *new; Chan *c; int i; new = smalloc(sizeof(Fgrp)); if(f == nil){ new->fd = smalloc(DELTAFD*sizeof(Chan*)); new->nfd = DELTAFD; new->ref.ref = 1; return new; } lock(&f->ref.lk); /* Make new fd list shorter if possible, preserving quantization */ new->nfd = f->maxfd+1; i = new->nfd%DELTAFD; if(i != 0) new->nfd += DELTAFD - i; new->fd = malloc(new->nfd*sizeof(Chan*)); if(new->fd == nil){ unlock(&f->ref.lk); free(new); error("no memory for fgrp"); } new->ref.ref = 1; new->maxfd = f->maxfd; for(i = 0; i <= f->maxfd; i++) { if((c = f->fd[i]) != nil){ incref(&c->ref); new->fd[i] = c; } } unlock(&f->ref.lk); return new; } void closefgrp(Fgrp *f) { int i; Chan *c; if(f == nil || decref(&f->ref)) return; for(i = 0; i <= f->maxfd; i++) if((c = f->fd[i]) != nil){ f->fd[i] = nil; cclose(c); } free(f->fd); free(f); } Mount* newmount(Chan *to, int flag, char *spec) { Mount *m; m = smalloc(sizeof(Mount)); m->to = to; incref(&to->ref); m->mountid = incref(&mountid); m->mflag = flag; if(spec != nil) kstrdup(&m->spec, spec); return m; } void mountfree(Mount *m) { Mount *f; while((f = m) != nil) { m = m->next; cclose(f->to); free(f->spec); free(f); } }