writeopen          19 kernel/pipe.c    int writeopen;  // write fd is still open
writeopen          34 kernel/pipe.c    pi->writeopen = 1;
writeopen          63 kernel/pipe.c      pi->writeopen = 0;
writeopen          69 kernel/pipe.c    if(pi->readopen == 0 && pi->writeopen == 0){
writeopen         113 kernel/pipe.c    while(pi->nread == pi->nwrite && pi->writeopen){  //DOC: pipe-empty