ref: c11957a7915d355d80ff7e6a21721ba05441ca29
dir: /libbio/binit.c/
#include "lib9.h" #include <bio.h> enum { MAXBUFS = 20 }; static Biobuf* wbufs[MAXBUFS]; static int atexitflag; static void batexit(void) { Biobuf *bp; int i; for(i=0; i<nelem(wbufs); i++) { bp = wbufs[i]; if(bp != 0) { wbufs[i] = 0; Bflush(bp); } } } static void deinstall(Biobuf *bp) { int i; for(i=0; i<nelem(wbufs); i++) if(wbufs[i] == bp) wbufs[i] = 0; } static void install(Biobuf *bp) { int i; deinstall(bp); for(i=0; i<nelem(wbufs); i++) if(wbufs[i] == 0) { wbufs[i] = bp; break; } if(atexitflag == 0) { atexitflag = 1; atexit(batexit); } } int Binits(Biobuf *bp, int f, int mode, uchar *p, int size) { p += Bungetsize; /* make room for Bungets */ size -= Bungetsize; switch(mode&~(OCEXEC|ORCLOSE|OTRUNC)) { default: fprint(2, "Bopen: unknown mode %d\n", mode); return Beof; case OREAD: bp->state = Bractive; bp->ocount = 0; break; case OWRITE: install(bp); bp->state = Bwactive; bp->ocount = -size; break; } bp->bbuf = p; bp->ebuf = p+size; bp->bsize = size; bp->icount = 0; bp->gbuf = bp->ebuf; bp->fid = f; bp->flag = 0; bp->rdline = 0; bp->offset = 0; bp->runesize = 0; return 0; } int Binit(Biobuf *bp, int f, int mode) { return Binits(bp, f, mode, bp->b, sizeof(bp->b)); } Biobuf* Bopen(char *name, int mode) { Biobuf *bp; int f; switch(mode&~(OCEXEC|ORCLOSE|OTRUNC)) { default: fprint(2, "Bopen: unknown mode %d\n", mode); return 0; case OREAD: f = open(name, OREAD); break; case OWRITE: f = create(name, mode, 0666); break; } if(f < 0) return 0; bp = malloc(sizeof(Biobuf)); if(bp == nil) return 0; Binits(bp, f, mode, bp->b, sizeof(bp->b)); bp->flag = Bmagic; return bp; } int Bterm(Biobuf *bp) { int r; deinstall(bp); r = Bflush(bp); if(bp->flag == Bmagic) { bp->flag = 0; close(bp->fid); bp->fid = -1; /* prevent accidents */ free(bp); } /* otherwise opened with Binit(s) */ return r; }